Telephone: Wikis

  
  

Encyclopedia

From Wikipedia, the free encyclopedia

Telephone
ATTtelephone-large.jpg
A 1970's era AT&T "Touch-Tone" telephone
Inventor Alexander Graham Bell
Launch year 1876
Available? Worldwide
.The telephone (from the Greek: τῆλε, tēle, "far" and φωνή, phōnē, "voice") is a telecommunications device that transmits and receives sound, most commonly the human voice.^ You'll have one antenna for the voice transmit channel, one antenna for the set up or control channel, and two antennas to receive.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to one another.^ In time division multiple access we separate calls by time, one after another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ For most of us, let's go through this again, this time from another point of view.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ "Most people see the cell as the blue hexagon, being defined by the tower in the center, with the antennae pointing in the directions indicated by the arrows.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

It is one of the most common household appliances in the developed world, and has long been considered indispensable to business, industry and government. The word "telephone" has been adapted to many languages and is widely recognized around the world.
The device operates principally by converting sound waves into electrical signals, and electrical signals into sound waves. .Such signals when conveyed through telephone networks — and often converted to electronic and/or optical signals — enable nearly every telephone user to communicate with nearly every other worldwide.^ A 30 kHz channel for cellular gives you great sound almost automatically, nearly on par with the normal telephone network.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Broad and deep knowledge of digital switching and transmission technology in the public switched telephone network, radio, signal processing, antennas, etc.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include (U+2121), (U+260E), (U+260F), and (U+2706).^ (Time division duplexing, as used in cordless telephone schemes: DECT and Personal Handy Phone systems might have a place but this still isn't clear.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Advanced Mobile Phone Service overcomes these problems be using a novel cellular approach.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Contents

History

Credit for the invention of the electric telephone is frequently disputed, and new controversies over the issue have arisen from time-to-time. .As with other great inventions such as radio, television, light bulb, and computer, there were several inventors who did pioneering experimental work on voice transmission over a wire and improved on each other's ideas.^ The CDG states that CDMA systems have seven advantages over other cellular radio transmission techniques.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Six sectored sites have been touted as a Great Thing by manufacturers such as Hughes and Motorola who want to sell you more equipment.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Innocenzo Manzetti, Antonio Meucci, Johann Philipp Reis, Elisha Gray, Alexander Graham Bell, and Thomas Edison, among others, have all been credited with pioneering work on the telephone.^ His interview on Alexander Graham Bell will air on the History Channel the end of 2006.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.An undisputed fact is that Alexander Graham Bell was the first to be awarded a patent for the electric telephone by the United States Patent and Trademark Office (USPTO) in March 1876.[1] That first patent by Bell was the master patent of the telephone, from which all other patents for electric telephone devices and features flowed.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ His interview on Alexander Graham Bell will air on the History Channel the end of 2006.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The early history of the telephone became and still remains a confusing morass of claims and counterclaims, which were not clarified by the huge mass of lawsuits that hoped to resolve the patent claims of many individuals and commercial competitors. The Bell and Edison patents, however, were forensically victorious and commercially decisive.
A Hungarian engineer, Tivadar Puskás quickly invented the telephone switchboard in 1876, which allowed for the formation of telephone exchanges, and eventually networks. [2]

Basic principles

1896 Telephone from Sweden.
.A traditional landline telephone system, also known as "plain old telephone service" (POTS), commonly handles both signaling and audio information on the same twisted pair of insulated wires: the telephone line.^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ AMPS is actually a hybrid system, combining both digital and analog signals.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ More recent systems (the MJ system at 150 KHz and the MK system at 450 KHz) [ Improved Mobile Telephone Service or IMTS, ed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Although originally designed for voice communication, the system has been adapted for data communication such as Telex, Fax and Internet communication.^ Although first in each cell's lineup, most radio engineers place priority on the voice channels in a system.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ AMPS, the older, analog voice system, not the digital IS-136, uses frequency shift keying to send data.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Rogers Communications unveiled new data plans designed to work with the launch of its much anticipated iPhone - and the pricing plans line up...

.The signaling equipment consists of a bell, beeper, light or other device to alert the user to incoming calls, and number buttons or a rotary dial to enter a telephone number for outgoing calls.^ All incoming and outgoing calls are then routed over this channel.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ New gadgets can be complicated at the best of times, especially when you have to overcome the complexities of overseas dialing codes and unfamiliar telephone number formats.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

A twisted pair line is preferred as it is more effective at rejecting electromagnetic interference (EMI) and crosstalk than an untwisted pair.
The telephone consists of an alerting device, usually a ringer, that remains connected to the phone line whenever the phone is "on hook", and other components which are connected when the phone is "off hook". These include a transmitter (microphone), a receiver (speaker) and other circuits for dialing, filtering, and amplification. .A calling party wishing to speak to another party will pick up the telephone's handset, thus operating a button switch or "switchhook", which puts the telephone into an active (off hook) state by connecting the transmitter (microphone), receiver (speaker) and related audio components to the line.^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Voice traffic is digitized and portions of many calls are put into a single bit stream, one sample at a time.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Your phone stops transmitting it once you pick up the handset or otherwise go off hook to answer the ring.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.This circuitry has a low resistance (less than 300 Ohms) which causes DC current (48 volts, nominal) from the telephone exchange to flow through the line.^ The data rate is 48.6 Kbits/s, less than a 56K modem, with each slot transmitting 324 bits in 6.67 ms. How is this rate determined?
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The exchange detects this DC current, attaches a digit receiver circuit to the line, and sends a dial tone to indicate readiness.^ To digress briefly, dial tone is not present on AMPS phones, although E.F. Johnson phones produced land line type dial tone within the unit.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.On a modern push-button telephone, the calling party then presses the number buttons in a sequence corresponding to the telephone number of the called party.^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The buttons are connected to a tone generator circuit that produces DTMF tones which end up at a circuit at the exchange. .A rotary dial telephone employs pulse dialing, sending electrical pulses corresponding to the telephone number to the exchange.^ To illustrate and compare, sending the number 175 in American Morse Code requires 11 pulses, three more than in binary code.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

(Most exchanges are still equipped to handle pulse dialing.) Provided the called party's line is not already active or "busy", the exchange sends an intermittent ringing signal (about 90 volts AC in North America and UK and 60 volts in Germany) to alert the called party to an incoming call. If the called party's line is active, the exchange sends a busy signal to the calling party. .However, if the called party's line is active but has call waiting installed, the exchange sends an intermittent audible tone to the called party to indicate an incoming call.^ Making a call, however, involves far more problems and resources than an incoming call does.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The phone's ringer is connected to the line through a capacitor, a device which blocks the flow of DC current but permits AC current. .This constitutes a mechanism whereby the phone draws no current when it is on hook, but exchange circuitry can send an AC voltage down the line to activate the ringer for an incoming call.^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ There was no secret that Nokia is coming up with the new fashion phone line-up this summer.

^ Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.When a landline phone is inactive or "on hook", the circuitry at the telephone exchange detects the absence of DC current flow and therefore "knows" that the phone is on hook with only the alerting device electrically connected to the line.^ Imagine dialing your landline phone without taking the receiver of the hook.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It would have to be a phone that can only call certain people.I'm very paranoid so it would make me feel better to know...

^ As we rely more heavily on mobile phones to stay connected, they increasingly know everything about us and have b...

.When a party initiates a call to this line, and the ringing signal is transmitted.^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.When the called party picks up the handset, they actuate a double-circuit switchhook which simultaneously disconnects the alerting device and connects the audio circuitry to the line.^ If it's a lousy call, they'll hang up.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Your phone stops transmitting it once you pick up the handset or otherwise go off hook to answer the ring.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ For the consumer CDMA appeals since a conversation can't be picked up with a scanner like an analog AMPS call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.This, in turn, draws DC current through the line, confirming that the called phone is now active.^ Through generous donations and the recycling of used cell phones, Robbie and Brittany have already distributed thousands of calling cards to soldiers around the globe.
  • Cellular Phone Directory of Florida 11 September 2009 20:57 UTC florida.uscity.net [Source type: General]

^ When you turn on your phone the mobile switch determines what cell will carry the call and assigns a vacant radio channel within that cell to take the conversation.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The exchange circuitry turns off the ring signal, and both phones are now active and connected through the exchange.^ Turning on and off the signal source in the above sequence represents the code.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Your phone stops transmitting it once you pick up the handset or otherwise go off hook to answer the ring.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The parties may now converse as long as both phones remain off hook.^ Both callers now hear each other's conversation.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A phone's MIN may change but the serial number remains the same.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Your phone stops transmitting it once you pick up the handset or otherwise go off hook to answer the ring.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.When a party "hangs up", placing the handset back on the cradle or hook, DC current ceases to flow in that line, signaling the exchange to disconnect the call.^ Cleardown or termination means hanging up, going on hook, or terminating a call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ "Once a call is up on a voice channel, all signaling is done on the voice channel via a scheme known as "Blank and Burst".
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ If it's a lousy call, they'll hang up.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Calls to parties beyond the local exchange are carried over "trunk" lines which establish connections between exchanges.^ This allocation is split equally between wire-line and radio common carriers (each is allocated 333 channels).
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In modern telephone networks, fiber-optic cable and digital technology are often employed in such connections.^ Broad and deep knowledge of digital switching and transmission technology in the public switched telephone network, radio, signal processing, antennas, etc.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Satellite technology may be used for communication over very long distances.
.In most telephones, the transmitter and receiver (microphone and speaker) are located in the handset, although in a speakerphone these components may be located in the base or in a separate enclosure.^ These courses have been given to staff of numerous US and foreign manufacturers of both mobile handset, mobile data, and base equipment.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Powered by the line, the transmitter produces an electric current whose voltage varies in response to the sound waves arriving at its diaphragm. .The resulting current is transmitted along the telephone line to the local exchange then on to the other phone (via the local exchange or a larger network), where it passes through the coil of the receiver.^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The first point is that cell phones and base stations transmit or communicate with each other on dedicated paired frequencies called channels.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ AT&T The NEW AT&T. Find a cell phone, browse cell phone plans and ringtones along with accessories for your needs at AT&T. AWS WIRELESS ACCESSORIES We offer the most up to date wireless phone accessory line.
  • Cellular Phone Directory of Florida 11 September 2009 20:57 UTC florida.uscity.net [Source type: General]

The varying voltage in the coil produces a corresponding movement of the receiver's diaphragm, reproducing the sound waves present at the transmitter.
A Lineman's handset is a telephone designed for testing the telephone network, and may be attached directly to aerial lines and other infrastructure components.

Early development

Early telephone with hand cranked generator.
  • 1844 — Innocenzo Manzetti first mooted the idea of a “speaking telegraph” (telephone).
  • 26 August 1854 — Charles Bourseul publishes an article in a magazine L'Illustration (Paris) : "Transmission électrique de la parole" [electric transmission of speech].
  • 26 October 1861 — Johann Philipp Reis (1834–1874) publicly demonstrated the Reis telephone before the Physical Society of Frankfurt
  • 22 August 1865, La Feuille d'Aoste reported “It is rumored that English technicians to whom Mr. Manzetti illustrated his method for transmitting spoken words on the telegraph wire intend to apply said invention in England on several private telegraph lines.”
  • 28 December 1871 — Antonio Meucci files a patent caveat (n.3335) in the U.S. Patent Office titled "Sound Telegraph", describing communication of voice between two people by wire.
  • 1874 — Meucci, after having renewed the caveat for two years, fails to find the money to renew it. The caveat lapses.
  • 6 April 1875 — Bell's U.S. Patent 161,739 "Transmitters and Receivers for Electric Telegraphs" is granted. .This uses multiple vibrating steel reeds in make-break circuits.
  • 11 February 1876 — Gray invents a liquid transmitter for use with a telephone but does not build one.
  • 14 February 1876 — Elisha Gray files a patent caveat for transmitting the human voice through a telegraphic circuit.
  • 14 February 1876 — Alexander Bell applies for the patent "Improvements in Telegraphy", for electromagnetic telephones using undulating currents.
  • 19 February 1876 — Gray is notified by the U.S. Patent Office of an interference between his caveat and Bell's patent application.^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ But CDMA does something like that, only using very low powered mobiles to reduce interference, and of course, some special coding.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ A telegraph key tap broke the circuit momentarily, transmitting a short pulse to a distant sounder, interpreted by an operator as a dot.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    .Gray decides to abandon his caveat.
  • 7 March 1876 — Bell's U.S. patent 174,465 "Improvement in Telegraphy" is granted, covering "the method of, and apparatus for, transmitting vocal or other sounds telegraphically … by causing electrical undulations, similar in form to the vibrations of the air accompanying the said vocal or other sound."
  • 10 March 1876 — The first successful telephone transmission of clear speech using a liquid transmitter when Bell spoke into his device, “Mr.^ (Time division duplexing, as used in cordless telephone schemes: DECT and Personal Handy Phone systems might have a place but this still isn't clear.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ The first point is that cell phones and base stations transmit or communicate with each other on dedicated paired frequencies called channels.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ The first law prohibits all drivers from using a handheld wireless telephone while operating a motor vehicle.

    .Watson, come here, I want to see you.” and Watson heard each word distinctly.
  • 30 January 1877 — Bell's U.S. patent 186,787 is granted for an electromagnetic telephone using permanent magnets, iron diaphragms, and a call bell.
  • 27 April 1877 — Edison files for a patent on a carbon (graphite) transmitter.^ If you want to see the whole graphic at once then click here.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ Click here if you want an illustrated overview of cell site layout .
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ Punch out the number that you want to call.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    The patent 474,230 was granted 3 May 1892, after a 15 year delay because of litigation. Edison was granted patent 222,390 for a carbon granules transmitter in 1879.

Early commercial instruments

Modern emergency telephone powered by sound alone.
Early telephones were technically diverse. Some used a liquid transmitter, some had a metal diaphragm that induced current in an electromagnet wound around a permanent magnet, and some were "dynamic" - their diaphragm vibrated a coil of wire in the field of a permanent magnet or the coil vibrated the diaphragm. .The dynamic kind survived in small numbers through the 20th century in military and maritime applications where its ability to create its own electrical power was crucial.^ Noise: Other vehicles, electric power transmission, industrial processing, etc., create broadband noise that impairs the channel, especially at 150 MHz and below.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Most, however, used the Edison/Berliner carbon transmitter, which was much louder than the other kinds, even though it required an induction coil, actually acting as an impedance matching transformer to make it compatible to the impedance of the line.^ Even though Ethiopia was listed as a country with coverage, I just could not believe that it would actually work there.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Apple s latest iPhone 3G will be more profitable than any other product in its line-up, which includes iPods, Macs, and iTunes.

^ It is much better than our cell phones we use everyday in Tennessee.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

The Edison patents kept the Bell monopoly viable into the 20th century, by which time the network was more important than the instrument.
Early telephones were locally powered, using either a dynamic transmitter or by the powering of a transmitter with a local battery. One of the jobs of outside plant personnel was to visit each telephone periodically to inspect the battery. .During the 20th century, "common battery" operation came to dominate, powered by "talk battery" from the telephone exchange over the same wires that carried the voice signals.^ This allocation is split equally between wire-line and radio common carriers (each is allocated 333 channels).
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A standard T1 transmission link carrying a DS-1 signal transmits 24 voice channels of about 4kHz each.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Early telephones used a single wire for the subscriber's line, with ground return used to complete the circuit (as used in telegraphs).^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Early digital wireless used a similar method with the telegraph.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The earliest dynamic telephones also had only one port opening for sound, with the user alternately listening and speaking (or rather, shouting) into the same hole.^ Every cell phone starts out with just one ESN. This number gets electronically burned into the phone's ROM, or read only memory chip.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The TDMA based IS-136 uses puts three calls into the same 30kz channel space that AMPS uses to carry one call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Sometimes the instruments were operated in pairs at each end, making conversation more convenient but also more expensive.
At first, the benefits of a telephone exchange were not exploited. .Instead telephones were leased in pairs to a subscriber, who had to arrange for a telegraph contractor to construct a line between them, for example between a home and a shop.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Users who wanted the ability to speak to several different locations would need to obtain and set up three or four pairs of telephones.^ They are so different (both in function and in how they are managed) that we never think of the set-up channel as the first of the cell's channels -- it's in a class by itself.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ At Mobal® we’ve chosen what we believe is the easiest system, which works in the same format wherever in the world you are — you never need to fiddle or set up your phone differently if you visit different countries — your Mobal® World Phone works seamlessly as you cross borders.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ In this example, just below , the cell site transmits and receives on three different sets of channels, one for each part or sector of the three cells it covers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Western Union, already using telegraph exchanges, quickly extended the principle to its telephones in New York City and San Francisco, and Bell was not slow in appreciating the potential.^ Cellular One has shut down roaming "privileges" altogether in New York City, Washington and Miami at different times.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Cellular Radio: Principles and Design, McGraw Hill, Inc., New York 1997 90.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Signalling began in an appropriately primitive manner. The user alerted the other end, or the exchange operator, by whistling into the transmitter. .Exchange operation soon resulted in telephones being equipped with a bell, first operated over a second wire, and later over the same wire, but with a condenser (capacitor) in series with the bell coil to allow the AC ringer signal through while still blocking DC (keeping the phone "on hook").^ To prevent any possible cross-subsidization or favoritism, the Bell operating companies must offer their cellular service through separate subsidiaries.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The first law prohibits all drivers from using a handheld wireless telephone while operating a motor vehicle.

^ The efficient use of frequencies that results from the cellular approach permits Advanced Mobile Phone Service customers to enjoy a level of service almost unknown with present mobile telephone service.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Telephones connected to the earliest Strowger automatic exchanges had seven wires, one for the knife switch, one for each telegraph key, one for the bell, one for the push-button and two for speaking.^ What's called "push to talk" since you must depress a microphone key or switch each time you want to talk.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Rural and other telephones that were not on a common battery exchange had a magneto or hand-cranked generator to produce a high voltage alternating signal to ring the bells of other telephones on the line and to alert the operator.^ This is unlike a landline telephone in which ringing gets produced at a central office or switch.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

A U.S. candlestick telephone in use, circa 1915.
In the 1890s a new smaller style of telephone was introduced, packaged in three parts. The transmitter stood on a stand, known as a "candlestick" for its shape. When not in use, the receiver hung on a hook with a switch in it, known as a "switchhook." Previous telephones required the user to operate a separate switch to connect either the voice or the bell. With the new kind, the user was less likely to leave the phone "off the hook". In phones connected to magneto exchanges, the bell, induction coil, battery and magneto were in a separate bell box called a "ringer box." [3] In phones connected to common battery exchanges, the ringer box was installed under a desk, or other out of the way place, since it did not need a battery or magneto.
.Cradle designs were also used at this time, having a handle with the receiver and transmitter attached, separate from the cradle base that housed the magneto crank and other parts.^ Once at the receiver the equipment identifies the call, separates its pieces from the spreading code and other calls, and returns the signal back to its original 9600 bit rate.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Using this method, a T1 line can carry 24 separate phone lines into your house or business with just an extra twisted pair.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It uses CDMA but is backward compatible with the analog based AMPS. IS-95 handles calls differently than TDMA schemes, although registration is the same.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.They were larger than the "candlestick" and more popular.^ In practice six sectors sites have been more trouble than they're worth.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Oh, and you have to perfectly control all customers so that they never attempt to use more resources than the system has available.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Disadvantages of single wire operation such as crosstalk and hum from nearby AC power wires had already led to the use of twisted pairs and, for long distance telephones, four-wire circuits.^ Using this method, a T1 line can carry 24 separate phone lines into your house or business with just an extra twisted pair.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Users at the beginning of the 20th century did not place long distance calls from their own telephones but made an appointment to use a special sound proofed long distance telephone booth furnished with the latest technology.^ From the user's standpoint, calls are initiated and received as they would be from any business or residence telephone.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ (Time division duplexing, as used in cordless telephone schemes: DECT and Personal Handy Phone systems might have a place but this still isn't clear.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Let's say you're making a long distance call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

What turned out to be the most popular and longest lasting physical style of telephone was introduced in the early 20th century, including Bell's Model 102. .A carbon granule transmitter and electromagnetic receiver were united in a single molded plastic handle, which when not in use sat in a cradle in the base unit.^ And instead of using a wire to connect to a distant receiver, you've used electromagnetic waves, silently passing energy and the information it carries across the atmosphere.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ That's since the mobile unit and the base station both need circuitry to transmit on one frequency while receiving on another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It uses CDMA but is backward compatible with the analog based AMPS. IS-95 handles calls differently than TDMA schemes, although registration is the same.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The circuit diagram of the Model 102 shows the direct connection of the receiver to the line, while the transmitter was induction coupled, with energy supplied by a local battery.^ And instead of using a wire to connect to a distant receiver, you've used electromagnetic waves, silently passing energy and the information it carries across the atmosphere.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The coupling transformer, battery, and ringer were in a separate enclosure. .The dial switch in the base interrupted the line current by repeatedly but very briefly disconnecting the line 1-10 times for each digit, and the hook switch (in the center of the circuit diagram) disconnected the line and the transmitter battery while the handset was on the cradle.^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ To digress briefly, dial tone is not present on AMPS phones, although E.F. Johnson phones produced land line type dial tone within the unit.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

After the 1930s, the base also enclosed the bell and induction coil, obviating the old separate ringer box. .Power was supplied to each subscriber line by central office batteries instead of a local battery, which required periodic service.^ Control equipment at the central office continually chooses an idle channel (if there is one) among the locally equipped complement of channels and marks it with an "idle" tone.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.For the next half century, the network behind the telephone became progressively larger and much more efficient, but after the dial was added the instrument itself changed little until American Telephone & Telegraph Company (AT&T) introduced Touch-Tone dialing in the 1960s.^ To progress from the early to the more mature configuration over a period of years, new cell sites can be added halfway between existing cell sites in stages.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ And as American Morse code was a logical, cohesive plan to send signals, much more complicated and useful arrangements have been devised.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Digital telephony

.The Public Switched Telephone Network (PSTN) has gradually evolved towards digital telephony which has improved the capacity and quality of the network.^ Broad and deep knowledge of digital switching and transmission technology in the public switched telephone network, radio, signal processing, antennas, etc.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.End-to-end analog telephone networks were first modified in the early 1960s by upgrading transmission networks with T1 carrier systems, designed to support the basic 3 kHZ voice channel by sampling the bandwidth-limited analog voice signal and encoding using PCM.^ Although first in each cell's lineup, most radio engineers place priority on the voice channels in a system.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ An uncompressed, non-multiplexed, bandwidth hogging analog signal simply sounds better than its present day compressed, digital counterpart.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Using this method, a T1 line can carry 24 separate phone lines into your house or business with just an extra twisted pair.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

While digitization allows wideband voice on the same channel, the improved quality of a wider analog voice channel did not find a large market in the PSTN.
Later transmission methods such as SONET and fiber optic transmission further advanced digital transmission. .Although analog carrier systems existed that multiplexed multiple analog voice channels onto a single transmission medium, digital transmission allowed lower cost and more channels multiplexed on the transmission medium.^ A five digit code called the home system identification number (SID or sometimes SIDH) identifies the cellular carrier your phone is registered with.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ If you ask an engineer in an AMPS system what channels he has on a cell, he'll automatically give you the voice channels.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ [More bandwidth] "The most noticeable disadvantage that is directly associated with digital systems is the additional bandwidth necessary to carry the digital signal as opposed to its analog counterpart.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Today the end instrument often remains analog but the analog signals are typically converted to digital signals at the (Serving Area Interface (SAI), central office (CO), or other aggregation point. .Digital loop carriers (DLC) place the digital network ever closer to the customer premises, relegating the analog local loop to legacy status.^ Remember, too, that an analog wave carries this digital information, just like most modems.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ IS-54 and now IS-136 co-exist with AMPS service, that is, a carrier can mix and match these digital and analog services on whatever channel sets they choose.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ [More bandwidth] "The most noticeable disadvantage that is directly associated with digital systems is the additional bandwidth necessary to carry the digital signal as opposed to its analog counterpart.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

IP telephony

Hardware-based IP phone.
.Internet Protocol (IP) telephony (also known as Voice over Internet Protocol, VoIP), is a disruptive technology that is rapidly gaining ground against traditional telephone network technologies.^ Broad and deep knowledge of digital switching and transmission technology in the public switched telephone network, radio, signal processing, antennas, etc.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.As of January 2005, up to 10% of telephone subscribers in Japan and South Korea have switched to this digital telephone service.^ Once the MTSO or mobile telephone switch assigns a voice channel the two frequencies making up the voice channel handle signaling during the actual conversation.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Broad and deep knowledge of digital switching and transmission technology in the public switched telephone network, radio, signal processing, antennas, etc.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

A January 2005 Newsweek article suggested that Internet telephony may be "the next big thing."[4] As of 2006 many VoIP companies offer service to consumers and businesses.
.IP telephony uses an Internet connection and hardware IP Phones or softphones installed on personal computers to transmit conversations encoded as data packets.^ (Time division duplexing, as used in cordless telephone schemes: DECT and Personal Handy Phone systems might have a place but this still isn't clear.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Demultiplexing those conversations is no more difficult than adding the right circuit board to a personal computer.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ We couldn't connect thru the internet but the Mobal World Phone worked just fine.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.In addition to replacing POTS (plain old telephone service), IP telephony services are also competing with mobile phone services by offering free or lower cost connections via WiFi hotspots.^ The latter is responsible for the high voice quality and high signaling reliability of the Advanced Mobile Phone Service.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ More recent systems (the MJ system at 150 KHz and the MK system at 450 KHz) [ Improved Mobile Telephone Service or IMTS, ed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Here's some great reading on the transition from mobile telephone service to cellular.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

VoIP is also used on private networks which may or may not have a connection to the global telephone network.
IP telephones have two notable disadvantages compared to traditional telephones. .Unless the IP telephone's components are backed up with an uninterruptible power supply or other emergency power source, the phone will cease to function during a power outage as can occur during an emergency or disaster, exactly when the phone is most needed.^ Once the MTSO or mobile telephone switch assigns a voice channel the two frequencies making up the voice channel handle signaling during the actual conversation.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A mobile phone runs a self diagnostic when it's powered up.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Verizon Wireless has just added a new mobile phone in its line-up useful and powerful mobile handsets.

.Traditional phones connected to the older PSTN network do not experience that problem since they are powered by the telephone company's battery supply, which will continue to function even if there's a prolonged power black-out.^ As we rely more heavily on mobile phones to stay connected, they increasingly know everything about us and have b...

^ Since there were so many qualified applicants, operating licenses were ultimately granted by the luck of a draw, not by a spectrum auction as they are today.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The two Spanish speakers can hear each other talking with out a problem, since their language or 'code' is so specific.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.A second distinct problem for an IP phone is the lack of a 'fixed address' which can impact the provision of emergency services such as police, fire or ambulance, should someone call for them.^ Making a call and getting a call from your cellular phone should be equally easy.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ NAMPS had the same fading problems as AMPS, lacked the error correction that digital systems provided and wasn't sophisticated enough to handle encryption or advanced services.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Things such as calling number identification, extension phone service and messaging.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Unless the registered user updates the IP phone's physical address location after moving to a new residence, emergency services can be, and have been, dispatched to the wrong location.^ Comes with an easy to follow user guide - giving you Mobal's global cell phone service with no monthly fees on your own cell phone!
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ In the international cell phone industry many new companies and services appear and disappear, leaving their customers searching for a replacement.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

Fixed telephone lines per 100 inhabitants 1997-2007

Usage

By the end of 2006, there were a total of nearly 4 billion mobile and fixed-line subscribers worldwide. This included 1.27 billion fixed-line subscribers and 2.68 billion mobile subscribers. [5]

Telephone operating companies

.In some countries, many telephone operating companies (commonly abbreviated to telco in American English) are in competition to provide telephone services.^ CDMA is a part of an overall operating system that provides cellular radio service.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Perhaps the biggest is, how many cellular companies (carriers) provide service to your location?
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The above Main article lists only facilities based providers and not companies which lease services from facilities based providers in order to serve their customers.^ When a system is newly installed in an area (when large cells are serving only a few customers), frequency reuse is unnecessary.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Perhaps the biggest is, how many cellular companies (carriers) provide service to your location?
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ If only 30% of your customers can use it, does it really provide capacity gains?
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Patents

.
  • US 174,465 -- Telegraphy (Bell's first telephone patent) -- Alexander Graham Bell
  • US 186,787 -- Electric Telegraphy (permanent magnet receiver) -- Alexander Graham Bell
  • US 474,230 -- Speaking Telegraph (graphite transmitter) -- Thomas Edison
  • US 203,016 -- Speaking Telephone (carbon button transmitter) -- Thomas Edison
  • US 222,390 -- Carbon Telephone (carbon granules transmitter) -- Thomas Edison
  • US 485,311 -- Telephone (solid back carbon transmitter) -- Anthony C. White (Bell engineer) This design was used until 1925 and installed phones were used until the 1940s.
  • US 3,449,750 -- Duplex Radio Communication and Signalling Appartus -- G. H. Sweigert
  • US 3,663,762 -- Cellular Mobile Communication System -- Amos Edward Joel (Bell Labs)
  • US 3,906,166 -- Radio Telephone System (DynaTAC cell phone) -- Martin Cooper et al.^ Since cellular uses radio waves to communicate signals are subject to the vagaries of the radio band.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ It's tough transferring a call between cells in any cellular radio system.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ The mobile sends its phone number, its electronic serial number, and its home system ID. Among other things.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    (Motorola)

See also

Notes

References

Further reading

  • Sobel, Robert (1974), The Entrepreneurs: Explorations Within the American Business Tradition. Weybright & Talley. .ISBN 0-679-40064-8.
  • Todd, Kenneth P. (1998), A Capsule History of the Bell System.^ This is from the long out of print A History of Engineering and Science in the Bell System: Communications Sciences (1925 -- 1980), prepared by members of the technical staff, AT&T Bell Laboratories, c.
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    ^ A History of Engineering and Science in the Bell System: Communications Sciences (1925 -- 1980) .
    • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

    American Telephone & Telegraph Company (AT&T).

External links


Source material

Up to date as of January 22, 2010
(Redirected to The Telephone article)

From Wikisource

The Telephone
by Robert Frost
From Mountain Interval, 1916.
“WHEN .I was just as far as I could walk
From here to-day,
There was an hour
All still
When leaning with my head against a flower
I heard you talk.
^ Talk Where you never could before...
  • Cellphoneantennas.com: Affordable Cell Phone Antennas - Cell Phone Antenna Amplifiers - CellPhone Signal Booster for Homes and Cars - Antenna for Cellphone - External RepeaterAntenna 31 January 2010 13:24 UTC cellphoneantennas.com [Source type: General]

^ So if you still want to flash your LG GT505 , follow my guide: .
  • LG Cell Phones Blog 31 January 2010 13:24 UTC www.lg-phones.org [Source type: General]

^ All items in original packaging and was my door step in 2 days.
  • Cell Phone Skins & Faceplates: Nokia, Motorola, Samsung Faceplates, iPhone & LG 31 January 2010 13:24 UTC www.cellularoutfitter.com [Source type: General]


.Don’t say I didn’t, for I heard you say—
You spoke from that flower on the window sill—
Do you remember what it was you said?”

“First tell me what it was you thought you heard.”

“Having found the flower and driven a bee away,
I leaned my head,
And holding by the stalk,
I listened and I thought I caught the word—
What was it?
^ Poser or not you decide, but don"t say we didn"t warn you.

^ You don't have to make an effort to remember.
  • People over 30 hate cell phones - Computerworld Blogs 31 January 2010 13:24 UTC blogs.computerworld.com [Source type: General]

^ Don't waste your time searching - we've already found you the best deals in the UK! But more importantly, we find you the best phones !
  • Mobile Phones UK >> Mobile phone reviews, consumer reviews and best buys: Apple iPhone 3G S, LG Cookie, Nokia 5530 XpressMusic, Nokia 5800 XpressMusic, Nokia 6303 Classic, Samsung Genio Touch, Samsung Jet, Samsung Tocco Lite 28 January 2010 1:30 UTC www.mobile-phones-uk.org.uk [Source type: General]

.Did you call me by my name?^ Amongst the mobile phone recycling companies featured at Sell My Mobile you can expect to see top named recyclers that allow you to sell mobile phone handsets with them: .
  • Sell Mobile Phone Price Comparison - Compare Prices at Envirofone, Fonebank, Mazuma & 13 others - Sell My Mobile 28 January 2010 1:30 UTC www.sellmymobile.com [Source type: General]

^ I regularly upgrade my mobile and you will be my first port of call to sell my old model in future..."

^ Now when you get a call on your cell phone and you do not recognize the cell phone number calling you, simply come to the Free Reverse Cell Phone Directory and enter the cell phone number to find the name associated with that number.


Or did you say—
Someone said ‘Come’—I heard it as I bowed.”

“I may have thought as much, but not aloud.”

“Well, so I came.”
PD-icon.svg This work is in the .public domain in the United States because it was published before January 1, 1923. It may be copyrighted outside the U.S. (see Help:Public domain).^ T-Mobile and Cingular operate GSM networks in the United States and as a subscriber on one of these networks you may already have a GSM world phone.
  • Using a Cell Phone Overseas 31 January 2010 13:24 UTC www.studyabroad.com [Source type: General]

^ Because of this, the FCC or The Federal Communications Commission, which is an independent agency of the United States government that regulating essentially all communications in or originating in the United States (including competition and fair play),...
  • Mobile Wire: Mobile Phone News 28 January 2010 1:30 UTC www.mobilewire.co.uk [Source type: General]

^ The federal universal service program is designed to help keep local telephone service rates affordable for all customers, in all areas of the United States.  .
  • Sweetser Telephone Company 11 January 2010 10:40 UTC sweetsertelephone.com [Source type: FILTERED WITH BAYES]

Flag of the United States.svg

1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

TELEPHONE (Gr. .TilXe, far, and qk vrl, voice).^ TilXe, far, and qk vrl, voice).

.Telephony is the art of reproducing sounds at a distance from their source, and a telephone is the instrument employed in sending or receiving such sounds.^ Telephony is the art of reproducing sounds at a distance from their source, and a telephone is the instrument employed in sending or receiving such sounds.

^ This only answers, however, for telephoning musical sounds to short distances.

^ The undefined sources were, in essence, a precaution by me to cover myself where sources occurred from uncommon or a new implementations in SIM, or simlar from external sources, such as mobile telephones.
  • Mobile Telephone Evidence: 11/01/2006 - 12/01/2006 11 September 2009 9:42 UTC trewmte.blogspot.com [Source type: FILTERED WITH BAYES]

.The term " telephony " was first used by Philipp Reis of Friedrichsdorf, in a lecture delivered before the Physical Society of Frankfort in 1861.1 But, although this lecture and Reis's subsequent work received considerable notice, little progress was made until the subject was taken up between 1874 and 1876 by Alexander Graham Bell, a native of Edinburgh, then resident in Boston, Mass., U.S.A. Bell, like Reis, employed electricity for the reproduction of sounds; but he attacked the problem in a totally different manner.^ The term " telephony " was first used by Philipp Reis of Friedrichsdorf , in a lecture delivered before the Physical Society of Frankfort in 1861.1 But, although this lecture and Reis's subsequent work received considerable notice, little progress was made until the subject was taken up between 1874 and 1876 by Alexander Graham Bell , a native of Edinburgh , then resident in Boston , Mass., U.S.A. Bell , like Reis, employed electricity for the reproduction of sounds; but he attacked the problem in a totally different manner.

^ This inventive schoolteacher was Alexander Graham Bell.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

^ The Mobile Mania In todays date, where we more than thank Alexander Graham Bell for inventing the telelphone, its also interesting to note that mot mobile phone users are known to match their personalities with the mobile instrument that they use.
  • Cell Phones 31 January 2010 13:24 UTC www.buzzle.com [Source type: FILTERED WITH BAYES]

.This will be better understood if we consider shortly on what the chief characteristics of sound depend.^ This will be better understood if we consider shortly on what the chief characteristics of sound depend.

.The sensation of sound is produced by rapid fluctuation in the pressure of the atmosphere on the tympanum of the Charac- ear.^ The sensation of sound is produced by rapid fluctuation in the pressure of the atmosphere on the tympanum of the Charac- ear .

^ If the fluctuations are irregular and non-periodic, teristics the sound is called a noise ; if they are cyclic and follow a regular and sufficiently rapid periodic law, the sound is musical.

^ When the connecting string is held taut and sounds, such as those of ordinary speech, are produced in front of one of the membranes, pulses corresponding to the fluctuations of the atmospheric pressure are transmitted along the string and communicated to the other membrane, which in its turn communicates them to the air , thus reproducing the sound.

.If the fluctuations are irregular and non-periodic, teristics the sound is called a noise; if they are cyclic and follow a regular and sufficiently rapid periodic law, the sound is musical.^ If the fluctuations are irregular and non-periodic, teristics the sound is called a noise ; if they are cyclic and follow a regular and sufficiently rapid periodic law, the sound is musical.

^ The sensation of sound is produced by rapid fluctuation in the pressure of the atmosphere on the tympanum of the Charac- ear .

^ Here in Maine they just passed a law called distracted driving.
  • Cell Phone Laws | WRKO 31 January 2010 13:24 UTC audio.wrko.com [Source type: Original source]

.In connexion with the present subject it is important to notice the three characteristics of a musical sound, namely, pitch, loudness and quality. The pitch of a musical sound depends on the number of cycles passed through by the fluctuations of the pressure per unit of time; the loudness depends on the amount or the amplitude of the fluctuation in each cycle; the quality depends on the form or the nature of the fluctuation in each cycle.^ In connexion with the present subject it is important to notice the three characteristics of a musical sound, namely, pitch , loudness and quality.

^ The pitch of a musical sound depends on the number of cycles passed through by the fluctuations of the pressure per unit of time; the loudness depends on the amount or the amplitude of the fluctuation in each cycle ; the quality depends on the form or the nature of the fluctuation in each cycle.

^ If the fluctuations are irregular and non-periodic, teristics the sound is called a noise ; if they are cyclic and follow a regular and sufficiently rapid periodic law, the sound is musical.

.The necessary condition for a successful system of telephony is the ability to reproduce these characteristics.^ The necessary condition for a successful system of telephony is the ability to reproduce these characteristics.

^ In both these examples all the three characteristics - pitch, relative intensity, and quality - of sound are reproduced.

.1 " - Ober Telephonie durch den galvanischen Strom," in Jahresber.^ Ober Telephonie durch den galvanischen Strom," in Jahresber.

d. physikalischen .Vereins
zu Frankfurt am Main, 1860-61, p.^ Vereins zu Frankfurt am Main, 1860-61, p.

57.
.In 1831 Wheatstone by his " magic lyre" experiment showed that, when the sounding-boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

.This only answers, however, for telephoning musical sounds to short distances.^ This only answers, however, for telephoning musical sounds to short distances.

^ In consequence of their high capacity, the attenuation constant of submarine cables is high, and only a small number of cables, of comparatively short length, are in use for telephonic purposes.

^ Minnesota, however, only reports the presence of a cellular telephone; not its use.
  • An Investigation of the Safety Implications of Wireless Communications in Vehicles DOT TOC 16 September 2009 22:41 UTC www.nhtsa.dot.gov [Source type: Reference]

.Another and somewhat similar example is furnished by what has been variously designated as the " string," toy," " lovers," and " mechanical " telephone.^ A system of wires, similar to that which connects the district exchanges in an area, links together the various local areas in the territory, and sometimes the territory of one administration with that of another.

^ The mobile communication exchanges are interconnected by transit switches, and each is connectable to a public switched telephone network or similar fixed network or to another mobile communication network via, e.g., a gateway office.
  • US Patent 6477364 - Automatic redialing method for a mobile communication network and a mobile communication system 20 September 2009 18:50 UTC www.wikipatents.com [Source type: Reference]

^ Another and somewhat similar example is furnished by what has been variously designated as the " string," toy ," " lovers," and " mechanical " telephone.

.ical tele- Two disks of thin metal, or two stretched membranes, each furnished with a mouthpiece, are connected together by a thin string or wire attached at each end to the centres of the membranes.^ RJ11 , 12 or 45 Connect two Cables together to extend the cable.
  • Telephone Cables, Modem Cables, Couplers, splitters, Wireless Telephone Jacks 11 January 2010 10:40 UTC www.action-electronics.com [Source type: General]

.A good example may be made with two cylindrical tin cups; the bottoms form the membranes and the cups the mouthpieces.^ A good example may be made with two cylindrical tin cups; the bottoms form the membranes and the cups the mouthpieces.

^ Again, the form of the opening or mouthpiece in front of the membrane exercised considerable 1 See A. G. Bell, " Telephone Researches," in Journ.

^ Two disks of thin metal , or two stretched membranes, each furnished with a mouthpiece , are connected together by a thin string or wire attached at each end to the centres of the membranes.

.When the connecting string is held taut and sounds, such as those of ordinary speech, are produced in front of one of the membranes, pulses corresponding to the fluctuations of the atmospheric pressure are transmitted along the string and communicated to the other membrane, which in its turn communicates them to the air, thus reproducing the sound.^ The sensation of sound is produced by rapid fluctuation in the pressure of the atmosphere on the tympanum of the Charac- ear .

^ When the connecting string is held taut and sounds, such as those of ordinary speech, are produced in front of one of the membranes, pulses corresponding to the fluctuations of the atmospheric pressure are transmitted along the string and communicated to the other membrane, which in its turn communicates them to the air , thus reproducing the sound.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

.In both these examples all the three characteristics - pitch, relative intensity, and quality - of sound are reproduced.^ In both these examples all the three characteristics - pitch, relative intensity, and quality - of sound are reproduced.

^ In connexion with the present subject it is important to notice the three characteristics of a musical sound, namely, pitch , loudness and quality.

^ As we have increased our exposure to both chemicals and EMFs in the last three decades we have seen certain brain cancers increase in all age groups by 1% a year.
  • Cell Phones 31 January 2010 13:24 UTC tuberose.com [Source type: Academic]

.In July 1837 Dr C. G. Page of Salem, Mass., drew attention to the sound given out by an electromagnet at the instant when the electric circuit is closed or broken, and in October of the same year he discussed, in a short article a entitled " Galvanic Music," the musical note pro- covery. duced by rapidly revolving the armature of an electromagnet in front of the poles.^ In July 1837 Dr C. G. Page of Salem, Mass., drew attention to the sound given out by an electromagnet at the instant when the electric circuit is closed or broken, and in October of the same year he discussed, in a short article a entitled " Galvanic Music ," the musical note pro- covery.

^ His first idea seems to have been to employ the vibrations of the current in an electric circuit, produced by moving the armature of an electromagnet included in the circuit nearer to or farther from the poles of the magnet.

^ The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.

.Experiments bearing on this subject were subsequently made by a great number of investigators.4 Page's discovery is of considerable importance in connexion with the theory of action of various forms of telephone, and was a very important feature in the early attempts by Reis to transit music and speech.^ Experiments bearing on this subject were subsequently made by a great number of investigators.4 Page's discovery is of considerable importance in connexion with the theory of action of various forms of telephone, and was a very important feature in the early attempts by Reis to transit music and speech.

^ The records of the telephone industry in Great Britain during the thirty years from 1877 to 1907 form an instructive chapter in the industrial history of the country.

^ The Cellular Telecommunications Industry Association (CTIA), various manufacturers as well as service providers have specifically focused on safe driving as an important consideration relating to cellular telephone use.
  • An Investigation of the Safety Implications of Wireless Communications in Vehicles DOT TOC 16 September 2009 22:41 UTC www.nhtsa.dot.gov [Source type: Reference]

.On the 26th of August 1854 there appeared in L'Illustration (Paris) an interesting article by Charles Bourseul on the electric transmission of speech.^ This is a very interesting article but I cannot seem to get the graphics to appear despite trying from a number of different machines and browsers.
  • Mobile Phones for Data Collection | MobileActive.org 28 January 2010 1:30 UTC mobileactive.org [Source type: FILTERED WITH BAYES]

^ The company's interest appears to be simple: there are more than a billion mobile phones in the world, and sales show no signs of slowing down.
  • mobile phone posts - Webware - CNET 28 January 2010 1:30 UTC news.cnet.com [Source type: General]

.5
The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.^ The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.

^ In July 1837 Dr C. G. Page of Salem, Mass., drew attention to the sound given out by an electromagnet at the instant when the electric circuit is closed or broken, and in October of the same year he discussed, in a short article a entitled " Galvanic Music ," the musical note pro- covery.

^ Sir W. Thomson (Lord Kelvin) observed in 1863 3 that when a condenser is charged or discharged, a sharp click is heard, and a similar observation was made by Cromwell F. Varley, who proposed to make use of it in a telegraphic receiving instrument.4 In Dolbear's instrument one plate of a condenser was a flexible diaphragm, connected with the telephone line in such a way that the varying electric potential produced by the action of the transmitting telephone caused an increased or diminished charge in the condenser.

.These suggestions were to some extent an anticipation of the work of Reis; but the conditions to be fulfilled before the sounds given out at the receiving station can be similar in pitch, quality and relative intensity to those produced at the transmitting station are not stated, and do not seem to have been appreciated.^ In both these examples all the three characteristics - pitch, relative intensity, and quality - of sound are reproduced.

^ These suggestions were to some extent an anticipation of the work of Reis; but the conditions to be fulfilled before the sounds given out at the receiving station can be similar in pitch, quality and relative intensity to those produced at the transmitting station are not stated, and do not seem to have been appreciated.

^ It sometimes occurs that the channel between the mobile station and the base station cannot be set up due to channel congestion or some other similar cause.
  • US Patent 6477364 - Automatic redialing method for a mobile communication network and a mobile communication system 20 September 2009 18:50 UTC www.wikipatents.com [Source type: Reference]

.In Reis's lecture an apparatus was described which has given rise to much discussion as to priority in the invention of the telephone.^ In Reis's lecture an apparatus was described which has given rise to much discussion as to priority in the invention of the telephone.

^ The draft agreement between the government and the National Telephone Company to carry out the policy of 1892 was submitted to parliament and led to much discussion.

.The instrument was described in over fifty publications 6 in various countries, and was well known to physicists previous to Bell's introduction of the electric telephone as a competitor with the electric telegraph.^ The instrument was described in over fifty publications 6 in various countries, and was well known to physicists previous to Bell's introduction of the electric telephone as a competitor with the electric telegraph .

^ Various states already have such laws in place, as well as certain cities across the country.

^ Western Electric manufactured telephones for both Bell telephone and Western Union.
  • Cybertelecom :: Telephone 11 January 2010 10:40 UTC www.cybertelecom.org [Source type: FILTERED WITH BAYES]

Reis caused a membrane to open and close an electric 2 See his Scientific Papers, P. 47.
a .See Silliman's Jour., xxxii.^ See Silliman's Jour., xxxii.

396, and xxxiii. 118.
4 Marrian, Phil. .Mag., 3rd ser., vol.^ Mag., 3rd ser., vol.

^ Mag., 5th ser., vol.

xxv. p. 382; Beatson, Arch. de l'Elect., v. .197; De la Rive, Treatise on Electricity, i.^ De la Rive, Treatise on Electricity, i.

306, also Phil. .Mag., 3rd ser., vol.^ Mag., 3rd ser., vol.

^ Mag., 5th ser., vol.

xxxv. p. 422, and Comp. Rend., xx. 1287, xxii. 432; Matteucci, Arch. de l'Elect., v. 389; Guillemin, Comp. Rend., xxii. 264; Wertheim, Comp. Rend., xxii. 33 6, 544, xxvi. 505, also Ann. de Chim. et de Phys., xxiii. 302, and Phil. .Mag., 3rd ser., vol.^ Mag., 3rd ser., vol.

^ Mag., 5th ser., vol.

xxviii. p. 544; Jannair, Comp. Rend., xxiii. 319; Joule, Phil. .Mag., 3rd ser., vol.^ Mag., 3rd ser., vol.

^ Mag., 5th ser., vol.

xxv. pp. 76, 225; Laborde, Comp. .Rend., 1.692; Poggendorff, Pogg.^ Rend., 1.692; Poggendorff, Pogg.

Ann.,
lxxxvii. 139, xeviii. .198; Du Moncel, Exp.^ Du Moncel, Exp.

de l'Elect., ii.
125, iii. 83; and Delesenne, Bibl. Univ. (1841), xvi. 406.
.See also Didaskalia: Blatter fib' Geist, Gemiith, u.^ See also Didaskalia: Blatter fib' Geist, Gemiith, u.

.Publiciteit,
Frankfort, No.^ Publiciteit, Frankfort, No.

.232, 28th September 1854; Du Moncel, Expose des Applications de l'Electricite (Paris), ii.^ September 1854; Du Moncel, Expose des Applications de l'Electricite (Paris), ii.

25, ed. 1854; iii. 110, ed. 1856, and Comp. Rend., 26th November 1877.
.6 The English reader may consult - Jour.^ The English reader may consult - Jour.

Soc. Tel. .Eng., March 1883; British Assoc.^ Eng., March 1883; British Assoc.

.Rep.,
1863; Civ.^ Rep., 1863; Civ.

Eng. and Arch. Jour.,
xxvi. .307; R. M. Ferguson, Electricity (London, 1866), p.^ R. M. Ferguson, Electricity (London, 1866), p.

257; S. P. Thompson, Philipp Reis, the Inventor of the Telephone (London, 1883).
circuit at each vibration, thus transmitting as many electric pulses through the circuit as there were vibrations in the sound. .These electric pulses were made to act on an electromagnet at the receiving station, which, in accordance with Page's discovery, gave out a sound of a pitch corresponding to the number of times it was magnetized or demagnetized per second.^ These electric pulses were made to act on an electromagnet at the receiving station, which, in accordance with Page's discovery, gave out a sound of a pitch corresponding to the number of times it was magnetized or demagnetized per second.

^ In July 1837 Dr C. G. Page of Salem, Mass., drew attention to the sound given out by an electromagnet at the instant when the electric circuit is closed or broken, and in October of the same year he discussed, in a short article a entitled " Galvanic Music ," the musical note pro- covery.

^ The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.

.Reis's object was to reproduce at a distance not only music but also human speech; but that he did not wholly succeed is clear from the following extract from his lecture: - " Hitherto it has not been possible to reproduce human speech with sufficient distinctness.^ The science required to send the human voice clear across the United States simply did not exist.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

.The consonants are for the most part reproduced pretty distinctly, but not the vowels as yet in an equal degree."^ The consonants are for the most part reproduced pretty distinctly, but not the vowels as yet in an equal degree."

.Considering the time at which he wrote, Reis seems to have understood very well the nature of the vibrations he had to reproduce, but he failed to comprehend how they could be reproduced by electricity.^ Considering the time at which he wrote, Reis seems to have understood very well the nature of the vibrations he had to reproduce, but he failed to comprehend how they could be reproduced by electricity.

^ TALK IS NOT CHEAP Narrator: In the summer of 1876, Bell and Watson were convinced the telephone could make money; they just didn't know how.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

^ If they simply weighted by age, Keeter wrote, pollsters would have "eliminated most of the bias that could occur from the underrepresentation of younger, more liberal voters."
  • Pollster.com: Cell Phones and Political Surveys: Part I 31 January 2010 13:24 UTC www.pollster.com [Source type: FILTERED WITH BAYES]

.His fundamental idea - the interruption of the current - was a fatal mistake, which was not at the time properly understood.^ His fundamental idea - the interruption of the current - was a fatal mistake, which was not at the time properly understood.

.The suggestion of Bourseul and the experiments of Reis are founded on the idea that a succession of currents, corresponding in number to the successive undulations of the pressure on the membrane of the transmitting instrument, could reproduce at the receiving station sounds of the same character as those produced at the sending station.^ The suggestion of Bourseul and the experiments of Reis are founded on the idea that a succession of currents, corresponding in number to the successive undulations of the pressure on the membrane of the transmitting instrument, could reproduce at the receiving station sounds of the same character as those produced at the sending station.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

^ These suggestions were to some extent an anticipation of the work of Reis; but the conditions to be fulfilled before the sounds given out at the receiving station can be similar in pitch, quality and relative intensity to those produced at the transmitting station are not stated, and do not seem to have been appreciated.

.Neither of them seemed to recognize anything as important except pitch and amplitude, and Reis thought the amplitude was to some extent obtained by the varying length of contact in the transmitting instrument.^ Neither of them seemed to recognize anything as important except pitch and amplitude, and Reis thought the amplitude was to some extent obtained by the varying length of contact in the transmitting instrument.

^ Multipath interference: Because the transmitted signal may travel over multiple paths of differing loss and length, the received signal in mobile communications varies rapidly in both amplitude and phase as the multiple signals reinforce or cancel one another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ These suggestions were to some extent an anticipation of the work of Reis; but the conditions to be fulfilled before the sounds given out at the receiving station can be similar in pitch, quality and relative intensity to those produced at the transmitting station are not stated, and do not seem to have been appreciated.

.This might possibly be true to a small extent; but, considering the small capacity of the circuits he used and the nature of his receiving instrument, it is hardly probable that duration of contact sensibly influenced the result.^ This might possibly be true to a small extent; but, considering the small capacity of the circuits he used and the nature of his receiving instrument, it is hardly probable that duration of contact sensibly influenced the result.

^ Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.

^ In consequence of their high capacity, the attenuation constant of submarine cables is high, and only a small number of cables, of comparatively short length, are in use for telephonic purposes.

.The quality of the sounds was to some extent also reproduced; but, judging from the results of later telephone investigation, it is highly probable that this was due, not to the varying duration, but to the varying firmness of the contact.^ STOCK ("Telephone Memories"): WATSON I could recognize the sound of Bell's voice and could almost understand some of his words.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

.The next worker at the telephone, and the one to whom the present great commercial importance of the instrument is due, Bell's re- was Bell.^ The next worker at the telephone, and the one to whom the present great commercial importance of the instrument is due, Bell's re- was Bell.

^ Bell's First Telephone (1875); one-fifth full size.

^ Chapter 5 presents a comprehensive review of simulator, and on-the-road, instrumented vehicle research conducted on cellular telephone use while driving.
  • An Investigation of the Safety Implications of Wireless Communications in Vehicles DOT TOC 16 September 2009 22:41 UTC www.nhtsa.dot.gov [Source type: Reference]

.His aim was the production, by means of the undulations of pressure on a membrane caused by sound, of an electric current the strength of which should at every instant vary directly as the pressure varied).^ His aim was the production, by means of the undulations of pressure on a membrane caused by sound, of an electric current the strength of which should at every instant vary directly as the pressure varied).

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

.His first idea seems to have been to employ the vibrations of the current in an electric circuit, produced by moving the armature of an electromagnet included in the circuit nearer to or farther from the poles of the magnet.^ His first idea seems to have been to employ the vibrations of the current in an electric circuit, produced by moving the armature of an electromagnet included in the circuit nearer to or farther from the poles of the magnet.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ The writer recommended the use of a flexible plate at the source of sound, which would vibrate in response to the varying pressure of the bons' air, and thus open and close an electric circuit, and of a similar plate at the receiving station, which would be acted on electromagnetically and thus give out as many pulsations as there are breaks in the current.

.He proposed to make the armature partake of the vibrations of the atmosphere either by converting it into a suitable vibrator or by controlling its vibrations by a stretched membrane of parchment armature had the form of a hinged lever one end, which pressed against the centre.^ He proposed to make the armature partake of the vibrations of the atmosphere either by converting it into a suitable vibrator or by controlling its vibrations by a stretched membrane of parchment armature had the form of a hinged lever one end, which pressed against the centre.

^ M was a membrane stretched by a ring R over the end of a tube T fixed at one side of the frame F. To the opposite side of the frame an electromagnet I was fixed with its axis in line with the tube T, and between the end of the electromagnet and the membrane a hinged armature A was arranged in such a way that its motion could be controlled by the membrane.

^ He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.

Fig. i shows the arrangement. .M was a membrane stretched by a ring R over the end of a tube T fixed at one side of the frame F. To the opposite side of the frame an electromagnet I was fixed with its axis in line with the tube T, and between the end of the electromagnet and the membrane a hinged armature A was arranged in such a way that its motion could be controlled by the membrane.^ M was a membrane stretched by a ring R over the end of a tube T fixed at one side of the frame F. To the opposite side of the frame an electromagnet I was fixed with its axis in line with the tube T, and between the end of the electromagnet and the membrane a hinged armature A was arranged in such a way that its motion could be controlled by the membrane.

^ He proposed to make the armature partake of the vibrations of the atmosphere either by converting it into a suitable vibrator or by controlling its vibrations by a stretched membrane of parchment armature had the form of a hinged lever one end, which pressed against the centre.

^ I radio or CD or even eat it a 100% in the control of that person group doing it -- one way interaction.
  • Cell Phone Laws | WRKO 31 January 2010 13:24 UTC audio.wrko.com [Source type: Original source]

.The instrument was joined in circuit with a battery and another similar instrument placed at a distance; and a continuous current was made to flow through the circuit, keeping the electromagnets energized.^ The instrument was joined in circuit with a battery and another similar instrument placed at a distance; and a continuous current was made to flow through the circuit, keeping the electromagnets energized.

^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ His first idea seems to have been to employ the vibrations of the current in an electric circuit, produced by moving the armature of an electromagnet included in the circuit nearer to or farther from the poles of the magnet.

.The experiments with this form were not successful, and, with the view of making the moving parts as light as possible, he substituted for the comparatively heavy lever armature a small piece of clock spring, about the size of a sixpence, glued to the centre of the diaphragm.^ The experiments with this form were not successful, and, with the view of making the moving parts as light as possible, he substituted for the comparatively heavy lever armature a small piece of clock spring, about the size of a sixpence, glued to the centre of the diaphragm .

^ It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet , and is capable of moving to and fro like a plunger when the diaphragm vibrates.

^ He proposed to make the armature partake of the vibrations of the atmosphere either by converting it into a suitable vibrator or by controlling its vibrations by a stretched membrane of parchment armature had the form of a hinged lever one end, which pressed against the centre.

.The magnet was mounted with its end carrying the coil opposite, and very close to, the centre of the piece of clock spring.^ The magnet was mounted with its end carrying the coil opposite, and very close to, the centre of the piece of clock spring.

^ The experiments with this form were not successful, and, with the view of making the moving parts as light as possible, he substituted for the comparatively heavy lever armature a small piece of clock spring, about the size of a sixpence, glued to the centre of the diaphragm .

.This answered sufficiently well to prove the feasibility of the plan, and subsequent experiments were directed to the discovery of the best form and arrangement of the parts.^ This answered sufficiently well to prove the feasibility of the plan, and subsequent experiments were directed to the discovery of the best form and arrangement of the parts.

^ A significant research effort, including well-planned animal experiments, is needed to provide the basis to assess the risk to human health of wireless communications devices.
  • Cell Phones 31 January 2010 13:24 UTC tuberose.com [Source type: Academic]

^ The business subsequently proved profitable, good dividends were paid, and the securities for the most part commanded a premium in the market.

.An increase in the size of the iron disk attached to the membrane augmented both the loudness and the distinctness of the sounds, and this finally led to the adoption of a thin iron disk supported round its edge, acting as both membrane and armature (fig.^ An increase in the size of the iron disk attached to the membrane augmented both the loudness and the distinctness of the sounds, and this finally led to the adoption of a thin iron disk supported round its edge, acting as both membrane and armature (fig.

^ D of thin sheet iron; in front of this was a cover M, M provided with a suitable cavity for directing the sound-waves against the diaphragm.

^ To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.

2). .Again, the form of the opening or mouthpiece in front of the membrane exercised considerable 1 See A. G. Bell, " Telephone Researches," in Journ.^ Again, the form of the opening or mouthpiece in front of the membrane exercised considerable 1 See A. G. Bell, " Telephone Researches," in Journ.

^ The Telephone Company, Limited, was formed to acquire Bell's patent.

^ A good example may be made with two cylindrical tin cups; the bottoms form the membranes and the cups the mouthpieces.

Soc Tel. Eng.,
31st October 1877.
influence on the efficiency of the instrument, and it was ultimately ascertained that a small central opening, with a thin air space extending across the face of the membrane, was best. .It was also found that comparatively small magnets were sufficient, and that there was no particular virtue in the closed circuit and electromagnet, but that a small permanent magnet having one pole in contact with FIG. 2. - Bell's Telephone (1877).^ It was also found that comparatively small magnets were sufficient, and that there was no particular virtue in the closed circuit and electromagnet, but that a small permanent magnet having one pole in contact with FIG. 2.

^ There's no real advantage to having either one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal .

.M, permanent magnet; E, electromagnet; C, diaphragm; t t,, terminals.^ It was also found that comparatively small magnets were sufficient, and that there was no particular virtue in the closed circuit and electromagnet, but that a small permanent magnet having one pole in contact with FIG. 2.

^ M, permanent magnet; E, electromagnet; C, diaphragm; t t,, terminals.

the end of the core of a short electromagnet, the coil of which was in circuit with the line, but which had no permanent current flowing through it, answered the purpose quite as well.' .The apparatus thus acted as both a transmitter and a receiver; indeed it is essentially the magneto-receiver which has come into universal use in practical telephony, though for transmission it was soon superseded by forms of microphonic transmitters.^ The apparatus thus acted as both a transmitter and a receiver ; indeed it is essentially the magneto-receiver which has come into universal use in practical telephony, though for transmission it was soon superseded by forms of microphonic transmitters.

^ A type of transmitter which has come to be invaluable in connexion with long distance telephony, and which has practically superseded all other forms, is the granular carbon transmitter.

^ The next transmitter of note was that introduced by Francis Blake, which came into wide use in the United States of America a.nd other countries.

.One of the latest forms of FIG. 3. - Double Pole Receiver.^ One of the latest forms of FIG. 3.

^ It was also found that comparatively small magnets were sufficient, and that there was no particular virtue in the closed circuit and electromagnet, but that a small permanent magnet having one pole in contact with FIG. 2.

^ Double Pole Receiver.

receiver, known as the double pole, is shown in fig. 3. M and M' are two permanent magnets; P and P' are soft iron pole-pieces upon which are placed the electromagnet coils C and C'; D is the diaphragm; I is a soft iron distance piece placed between the magnets at the end remote from the diaphragm; B is the brass body of the instrument, over which is placed a thin ebonite shell S. E is the ear-piece made of ebonite; F is a cap of the same material enclosing the receiver terminals, which are mounted upon the ebonite block G, attached to the distance piece I.
.A telephone transmitter and a receiver on a novel plan were patented in July 1877 by Edison, shortly after the introduction of Bell's instruments.^ A telephone transmitter and a receiver on a novel plan were patented in July 1877 by Edison, shortly after the introduction of Bell's instruments.

^ On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.

^ Edison's telephone patent was granted for the United Kingdom.

.The receiver was based on the change of friction produced by the passage of an electric current through the point of contact of certain substances in relative motion.^ The receiver was based on the change of friction produced by the passage of an electric current through the point of contact of certain substances in relative motion.

^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

^ His first idea seems to have been to employ the vibrations of the current in an electric circuit, produced by moving the armature of an electromagnet included in the circuit nearer to or farther from the poles of the magnet.

.In one form a drum, mounted on an axis and covered by a band of paper soaked in a solution of caustic potash, was turned under a spring the end of which was in contact through a platinum point with the paper.^ In one form a drum , mounted on an axis and covered by a band of paper soaked in a solution of caustic potash, was turned under a spring the end of which was in contact through a platinum point with the paper.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ The spring was attached to the centre of a diaphragm in such a way that, when the drum was turned, the friction between the point of the spring and the paper deflected !

.The spring was attached to the centre of a diaphragm in such a way that, when the drum was turned, the friction between the point of the spring and the paper deflected !^ The spring was attached to the centre of a diaphragm in such a way that, when the drum was turned, the friction between the point of the spring and the paper deflected !

^ In one form a drum , mounted on an axis and covered by a band of paper soaked in a solution of caustic potash, was turned under a spring the end of which was in contact through a platinum point with the paper.

^ And but that's quite such a great temptation and that's why I have come to the point literally -- I turn this thing off and I need to put it in my purse.
  • Cell Phone Laws | WRKO 31 January 2010 13:24 UTC audio.wrko.com [Source type: Original source]

the diaphragm. .The current from the line was made to pass through the spring and paper to the cylinder.^ The current from the line was made to pass through the spring and paper to the cylinder .

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

.Now it had been previously shown by Edison that, when a current was made to pass through an arrangement like that just described, the friction between the paper and the spring was greatly diminished.^ The current from the line was made to pass through the spring and paper to the cylinder .

^ Now it had been previously shown by Edison that, when a current was made to pass through an arrangement like that just described, the friction between the paper and the spring was greatly diminished.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence, R.I.
,?.?;??...
i. i. ??_,..... .6 ii 74,+ In the early trials the of iron carrying a stud at of a stretched membrane FIG. 1. - Bell's First Telephone (1875); one-fifth full size.^ In the early trials the of iron carrying a stud at of a stretched membrane FIG. 1.

^ Bell's First Telephone (1875); one-fifth full size.

^ The difficulty was first satisfactorily overcome in the long-distance transmitter, invented by A. C. White in the laboratory of the American Bell Telephone Company, and commonly known as the " solid back transmitter " (fig.

.FIG. 4. - Edison's Microphone Transmitter.^ Edison's Microphone Transmitter.

currents, and sounds were given out corresponding in pitch, and also to some extent in quality, with the sounds produced at the transmitting station. .A cylinder of chalk was used in some of Edison's later experiments with this receiver.^ A cylinder of chalk was used in some of Edison's later experiments with this receiver.

The transmitter (fig. .4), in an early form, consisted of a cell of insulating material having at its bottom a flat-headed platinum screw G; on the top of G was a layer of carbon powder C, on the top of that a platinum disk D, and above that again, forming the cover of the cell, a disk of ivory B, held in position by a ring E. Resting on the centre of the ivory disk was a small piece of rubber tubing, and this was lightly pressed by the diaphragm A, which was held in place by the mouthpiece M. The varying pressure on A, when a sound was produced near it, caused corresponding variations in the pressure on the carbon powder, and this produced similar variations in its electric resistance.^ G; on the top of G was a layer of carbon powder C, on the top of that a platinum disk D, and above that again, forming the cover of the cell, a disk of ivory B, held in position by a ring E. Resting on the centre of the ivory disk was a small piece of rubber tubing, and this was lightly pressed by the diaphragm A, which was held in place by the mouthpiece M. The varying pressure on A, when a sound was produced near it, caused corresponding variations in the pressure on the carbon powder, and this produced similar variations in its electric resistance.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ Some earlier flip phones had a small brick-like form factor with a hinge at the bottom of the phone that was attached to a flat piece of plastic which flipped up to cover the keypad but left the display screen exposed.
  • MOBILE PHONES HISTORY AND DEVELOPMENT ONLINE CHEAP BEST VALUE BARGAINS AIRTIME TEXTS VIDEO MESSAGING DEALS 28 January 2010 1:30 UTC www.bluebird-electric.net [Source type: FILTERED WITH BAYES]

.Experiments very similar to these of Edison were made by Elisha Gray of Boston, Mass., and described by him in papers communicated to the American Electrical Society in 1875 and 1878. In these experiments the electric current passed through the fingers of the operator's hand, which thus took the place of the spring in Edison's apparatus.^ The current from the line was made to pass through the spring and paper to the cylinder .

^ Experiments very similar to these of Edison were made by Elisha Gray of Boston, Mass., and described by him in papers communicated to the American Electrical Society in 1875 and 1878.

^ These devices have made our lives very simple for communicating.

.The diaphragm was itself used as the rubbing surface, and it was either mounted and rotated or the fingers were moved over it.^ The diaphragm was itself used as the rubbing surface, and it was either mounted and rotated or the fingers were moved over it.

.When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.

.The application of this apparatus to the transmission of music was described by Gray.'^ The application of this apparatus to the transmission of music was described by Gray .'

.In another form of telephone, brought prominently forward by Professor A. E. Dolbear, 2 the effects were produced by electrostatic instead of electromagnetic forces, as in con- the Bell telephone.^ A light opera called Cupid's Telephone brought Bell's invention to Broadway -- and the silent movies embraced the talking machine right from the beginning.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

^ Narrator: In the courtroom, Bell was an ideal witness: literate, poised and forceful.- Louis Galambos: Well, he brought believability.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

^ Bell"): Alexander Graham Bell stands on stage with one telephone; Thomas Watson stands in a small room with another.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

.Sir W. Thomson (Lord Kelvin) observed in 1863 3 that when a condenser is charged or discharged, a sharp click is heard, and a similar observation was made by Cromwell F. Varley, who proposed to make use of it in a telegraphic receiving instrument.4 In Dolbear's instrument one plate of a condenser was a flexible diaphragm, connected with the telephone line in such a way that the varying electric potential produced by the action of the transmitting telephone caused an increased or diminished charge in the condenser.^ Sir W. Thomson (Lord Kelvin) observed in 1863 3 that when a condenser is charged or discharged, a sharp click is heard, and a similar observation was made by Cromwell F. Varley, who proposed to make use of it in a telegraphic receiving instrument.4 In Dolbear's instrument one plate of a condenser was a flexible diaphragm, connected with the telephone line in such a way that the varying electric potential produced by the action of the transmitting telephone caused an increased or diminished charge in the condenser.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ Watson quickly constructed a new device, placing a lamb skin diaphragm opposite a magnet in a transmitter, running a connecting wire through sulfuric acid, causing the receiving membrane to vibrate.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

.This alteration of charge caused a corresponding change in the mutual attraction of the plates of the condenser; hence the flexible plate was made to copy the vibrations of the diaphragm of the transmitter.^ This alteration of charge caused a corresponding change in the mutual attraction of the plates of the condenser; hence the flexible plate was made to copy the vibrations of the diaphragm of the transmitter.

^ Watson quickly constructed a new device, placing a lamb skin diaphragm opposite a magnet in a transmitter, running a connecting wire through sulfuric acid, causing the receiving membrane to vibrate.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

^ Sir W. Thomson (Lord Kelvin) observed in 1863 3 that when a condenser is charged or discharged, a sharp click is heard, and a similar observation was made by Cromwell F. Varley, who proposed to make use of it in a telegraphic receiving instrument.4 In Dolbear's instrument one plate of a condenser was a flexible diaphragm, connected with the telephone line in such a way that the varying electric potential produced by the action of the transmitting telephone caused an increased or diminished charge in the condenser.

.It is obvious that this apparatus might be used either as a transmitter or as a receiver, but that the effects must under ordinary circumstances be in either case extremely feeble.^ It is obvious that this apparatus might be used either as a transmitter or as a receiver, but that the effects must under ordinary circumstances be in either case extremely feeble.

^ The apparatus thus acted as both a transmitter and a receiver ; indeed it is essentially the magneto-receiver which has come into universal use in practical telephony, though for transmission it was soon superseded by forms of microphonic transmitters.

^ This article generally looked at how data that are deleted and that might be subsequently recovered and used as evidence may be viewed following the case of R .v.
  • Mobile Telephone Evidence: 11/01/2006 - 12/01/2006 11 September 2009 9:42 UTC trewmte.blogspot.com [Source type: FILTERED WITH BAYES]

.It was very early recognized - and, indeed, is mentioned in the first patents of Bell, and in a caveat filed by Elisha Gray in the United States patent office only some two hours after Bell's application for a patent - that sounds and spoken words might be transmitted to a distance by causing the vibrations of a diaphragm to vary the resistance in the circuit.^ It was very early recognized - and, indeed, is mentioned in the first patents of Bell, and in a caveat filed by Elisha Gray in the United States patent office only some two hours after Bell's application for a patent - that sounds and spoken words might be transmitted to a distance by causing the vibrations of a diaphragm to vary the resistance in the circuit.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ Robert Bruce : The remarkable coincidence, as it seemed, of Elisha Gray's caveat being entered on the same day that Bell's patent application was, has raised a debate that still continues, and I think altogether unnecessarily.
  • American Experience . Technology . The Telephone . The Film & More | Program Transcript | PBS 11 January 2010 10:40 UTC www.pbs.org [Source type: FILTERED WITH BAYES]

.Both Bell and Gray proposed to do this by introducing a column of liquid into the circuit, the length or the resistance of which could be varied by causing the vibrations of the diaphragm to vary the depth of immersion of a light rod fixed to it and dipping into the liquid.^ He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.

^ Both Bell and Gray proposed to do this by introducing a column of liquid into the circuit, the length or the resistance of which could be varied by causing the vibrations of the diaphragm to vary the depth of immersion of a light rod fixed to it and dipping into the liquid.

^ It was very early recognized - and, indeed, is mentioned in the first patents of Bell, and in a caveat filed by Elisha Gray in the United States patent office only some two hours after Bell's application for a patent - that sounds and spoken words might be transmitted to a distance by causing the vibrations of a diaphragm to vary the resistance in the circuit.

.On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.^ This seems to have been the first transmitter in which it was proposed to use the resistance at the contact of two conductors.

^ Almost simultaneously with Berliner, Edison conceived the idea of using a variable resistance transmitter.

^ On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.

.The caveat was illustrated by a sketch showing a diaphragm with a metal patch in the See George B. Prescott, The Speaking Telephone (London, 1879), pp.^ The caveat was illustrated by a sketch showing a diaphragm with a metal patch in the See George B. Prescott, The Speaking Telephone (London, 1879), pp.

.151-205.2 Scientific American, 18th June 1881. Electrostatics and Magnetism, p.^ Scientific American, 18th June 1881.

236.
4 See Tel. .Journ., 1st August 1877, p.^ Journ., 1st August 1877, p.

178, also Adams, Journ. Soc. Tel. .Eng., 18 77, p.^ Eng., 18 77, p.

476.
centre, against which a metal knob was lightly pressed by an adjusting screw. .This seems to have been the first transmitter in which it was proposed to use the resistance at the contact of two conductors.^ This seems to have been the first transmitter in which it was proposed to use the resistance at the contact of two conductors.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ Almost simultaneously with Berliner, Edison conceived the idea of using a variable resistance transmitter.

.Almost simultaneously with Berliner, Edison conceived the idea of using a variable resistance transmitter.^ Almost simultaneously with Berliner, Edison conceived the idea of using a variable resistance transmitter.

^ This seems to have been the first transmitter in which it was proposed to use the resistance at the contact of two conductors.

.5 He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.^ He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.

^ He sometimes held the carbon powder against the diaphragm in a small tr ans' shallow cell (from a quarter to half an inch in diameter and about an eighth of an inch deep), and sometimes he used what he describes as a fluff, that is, a little brush of silk fibre with plumbago rubbed into it.

^ Both Bell and Gray proposed to do this by introducing a column of liquid into the circuit, the length or the resistance of which could be varied by causing the vibrations of the diaphragm to vary the depth of immersion of a light rod fixed to it and dipping into the liquid.

.He sometimes held the carbon powder against the diaphragm in a small tr ans' shallow cell (from a quarter to half an inch in diameter and about an eighth of an inch deep), and sometimes he used what he describes as a fluff, that is, a little brush of silk fibre with plumbago rubbed into it.^ He sometimes held the carbon powder against the diaphragm in a small tr ans' shallow cell (from a quarter to half an inch in diameter and about an eighth of an inch deep), and sometimes he used what he describes as a fluff, that is, a little brush of silk fibre with plumbago rubbed into it.

^ The microphonic arrangement consisted of a spring S, about the hundredth of an inch thick and the eighth of an inch broad, fixed at one end to a lever L, and carrying at its free extremity a brass block W. In one side of W a small disk C of gas carbon was inserted, resting on the hemispherical end of a small platinum pin K, about the twentieth of an inch in diameter, held in position by a thin spring A. The pressure of the carbon on the platinum point could be adjusted by the screw N, which turned the lever about the flexible joint G. The electrical connexions of the instrument as arranged for actual use are also illustrated in the figure.

^ He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.

.In another form the plumbago powder was worked into a button cemented together with syrup and other substances.^ In another form the plumbago powder was worked into a button cemented together with syrup and other substances.

.In the specification of the patent applied for on the list of July 1877 he showed a sketch of an instrument which consisted of a diaphragm, with a small platinum patch in the centre for an electrode, against which a hard point, made of plumbago powder cemented together with india-rubber and vulcanized, was pressed by a long spring, the pressure of the carbon against the platinum disk being adjusted by a straining screw near the base of the spring.^ In it the electrodes were of platinum and carbon.

^ In the specification of the patent applied for on the list of July 1877 he showed a sketch of an instrument which consisted of a diaphragm, with a small platinum patch in the centre for an electrode, against which a hard point, made of plumbago powder cemented together with india -rubber and vulcanized, was pressed by a long spring, the pressure of the carbon against the platinum disk being adjusted by a straining screw near the base of the spring.

^ The microphonic arrangement consisted of a spring S, about the hundredth of an inch thick and the eighth of an inch broad, fixed at one end to a lever L, and carrying at its free extremity a brass block W. In one side of W a small disk C of gas carbon was inserted, resting on the hemispherical end of a small platinum pin K, about the twentieth of an inch in diameter, held in position by a thin spring A. The pressure of the carbon on the platinum point could be adjusted by the screw N, which turned the lever about the flexible joint G. The electrical connexions of the instrument as arranged for actual use are also illustrated in the figure.

.Subsequently he filed an application for a patent in which various forms of springs and weights assisted in maintaining the contacts and otherwise improved the instrument.^ Subsequently he filed an application for a patent in which various forms of springs and weights assisted in maintaining the contacts and otherwise improved the instrument.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ One of the electrodes was attached to a sounding board capable of being vibrated by sound-waves and the other was held either by springs or weights in delicate contact with it.

.In the early part of 1878 Professor D. E. Hughes, while engaged in experiments upon a Bell telephone in an electric circuit, discovered that a peculiar noise was produced whenever two hard electrodes, such as two wires, were - drawn across each other, or were made to touch each other with a variable degree of firmness.^ In the early part of 1878 Professor D. E. Hughes, while engaged in experiments upon a Bell telephone in an electric circuit, discovered that a peculiar noise was produced whenever two hard electrodes, such as two wires, were - drawn across each other, or were made to touch each other with a variable degree of firmness.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

.Acting upon this discovery, he constructed an instrument which he called a " microphone," 6 and which consisted essentially of two hard carbon electrodes placed in contact, with a current passing through the point of contact and a telephone included in the same circuit.^ Acting upon this discovery, he constructed an instrument which he called a " microphone," 6 and which consisted essentially of two hard carbon electrodes placed in contact, with a current passing through the point of contact and a telephone included in the same circuit.

^ The average cost of constructing an exchange circuit in the metropolitan area (including the installation of telephone instruments and of exchange apparatus, but excluding the provision of spare plant) has been £33.

^ On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.

.One of the electrodes was attached to a sounding board capable of being vibrated by sound-waves and the other was held either by springs or weights in delicate contact with it.^ One of the electrodes was attached to a sounding board capable of being vibrated by sound-waves and the other was held either by springs or weights in delicate contact with it.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

^ When the sounding board was spoken to or subjected to sound-waves, the mechanical resistance of the loose electrode, due to its weight, or the spring, or both, served to vary the pressure at the contact, and this gave to the current a form corresponding to the sound-waves, and it was therefore capable of being used as a speaking-telephone transmitter.'

.When the sounding board was spoken to or subjected to sound-waves, the mechanical resistance of the loose electrode, due to its weight, or the spring, or both, served to vary the pressure at the contact, and this gave to the current a form corresponding to the sound-waves, and it was therefore capable of being used as a speaking-telephone transmitter.'^ One of the electrodes was attached to a sounding board capable of being vibrated by sound-waves and the other was held either by springs or weights in delicate contact with it.

^ When the sounding board was spoken to or subjected to sound-waves, the mechanical resistance of the loose electrode, due to its weight, or the spring, or both, served to vary the pressure at the contact, and this gave to the current a form corresponding to the sound-waves, and it was therefore capable of being used as a speaking-telephone transmitter.'

^ On the 4th of April 1877 Emile Berliner filed a caveat in the United States patent office, in which he stated that, on the principle of the variation with pressure of the resistance at the contact of two conductors, he had made an instrument which could be used as a telephone transmitter, and that, in consequence of the mutual forces between the two parts of the current on the two sides of the point of contact, the instrument was capable of acting as a receiver.

.The next transmitter of note was that introduced by Francis Blake, which came into wide use in the United States of America a.nd other countries.^ The next transmitter of note was that introduced by Francis Blake, which came into wide use in the United States of America a.nd other countries.

^ It is widely used in America, and was introduced into Great Britain in 1907.

^ Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.

.In it the electrodes were of platinum and carbon.^ In it the electrodes were of platinum and carbon.

To a frame F (fig. 5) was attached a diaphragm D of thin sheet iron; in front of this was a cover M, M provided with a suitable cavity for directing the sound-waves against the diaphragm. .The microphonic arrangement consisted of a spring S, about the hundredth of an inch thick and the eighth of an inch broad, fixed at one end to a lever L, and carrying at its free extremity a brass block W. In one side of W a small disk C of gas carbon was inserted, resting on the hemispherical end of a small platinum pin K, about the twentieth of an inch in diameter, held in position by a thin spring A. The pressure of the carbon on the platinum point could be adjusted by the screw N, which turned the lever about the flexible joint G. The electrical connexions of the instrument as arranged for actual use are also illustrated in the figure.^ The microphonic arrangement consisted of a spring S, about the hundredth of an inch thick and the eighth of an inch broad, fixed at one end to a lever L, and carrying at its free extremity a brass block W. In one side of W a small disk C of gas carbon was inserted, resting on the hemispherical end of a small platinum pin K, about the twentieth of an inch in diameter, held in position by a thin spring A. The pressure of the carbon on the platinum point could be adjusted by the screw N, which turned the lever about the flexible joint G. The electrical connexions of the instrument as arranged for actual use are also illustrated in the figure.

^ In one form a drum , mounted on an axis and covered by a band of paper soaked in a solution of caustic potash, was turned under a spring the end of which was in contact through a platinum point with the paper.

^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

.The current circuit went through S, W, C, K, A, and the primary circuit of the induction coil I to the battery B, and thence to S again.^ The current from the battery passes from one of the carbon disks to the other through the particles of granulated carbon which fill the space between them.

^ The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.

^ The subscriber's meter is joined in multiple with the cut-off relay, and whenever a peg is connected to the circuit a current flows through the meter.

.This formed a local circuit at the transmitting station.^ This formed a local circuit at the transmitting station.

.The line of circuit passed through the secondary of the induction coil I to the line, from that to the telephone T at the receiving station, 'See Journal of the Telegraph, New York, April 1877; Philadelphia Times, 9th July 1877; and Scientific American, August 181 This term was used by Wheatstone in 1827 for an acoustic apparatus intended to convert very feeble into audible sounds; see his Scientific Papers, p.^ The current from the line was made to pass through the spring and paper to the cylinder .

^ The line of circuit passed through the secondary of the induction coil I to the line, from that to the telephone T at the receiving station, 'See Journal of the Telegraph, New York , April 1877; Philadelphia Times, 9th July 1877; and Scientific American, August 181 This term was used by Wheatstone in 1827 for an acoustic apparatus intended to convert very feeble into audible sounds; see his Scientific Papers, p.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

32.
' See Proc. Roy. Soc., xxvii. 362; Proc. Phys. Soc., ii. 255; Phil. .Mag., 5th ser., vol.^ Mag., 3rd ser., vol.

^ Mag., 5th ser., vol.

vi. p. 44; W. H. Preece, Journ. Soc. Tel. Eng., vii. .270. Gray's and then either to earth or back to the induction coil by a return line of wire.^ Gray's and then either to earth or back to the induction coil by a return line of wire.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.

.Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.^ Two methods of " multipling " have been much used.

^ Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.

^ Transmitting binary or digital information today is, of course, much more complicated and faster than sending Morse code.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In this several microphonic joints were employed.^ In this several microphonic joints were employed.

FIG. 5. - Blake's Transmitter.
.Thus, in the Crossley transmitter four hard carbon pencils were arranged in a lozenge-shaped figure, the ends of each pencil resting loosely in a small carbon block.^ Thus, in the Crossley transmitter four hard carbon pencils were arranged in a lozenge -shaped figure, the ends of each pencil resting loosely in a small carbon block.

^ In the Ader transmitter as many as twelve carbon pencils were employed, arranged in a series of two groups with six pencils in parallel in each group.

.These blocks were fastened to a diaphragm of wood.^ These blocks were fastened to a diaphragm of wood.

.The circuit connexions were such that two adjacent sides of the lozenge were in parallel and two in series.^ The circuit connexions were such that two adjacent sides of the lozenge were in parallel and two in series.

^ An improvement was effected in this respect by the introduction of the " bridging " system, in which the bells possessing high inductance are placed in parallel between the two wires of the circuit.

^ In the Ader transmitter as many as twelve carbon pencils were employed, arranged in a series of two groups with six pencils in parallel in each group.

.In the Ader transmitter as many as twelve carbon pencils were employed, arranged in a series of two groups with six pencils in parallel in each group.^ In the Ader transmitter as many as twelve carbon pencils were employed, arranged in a series of two groups with six pencils in parallel in each group.

^ The circuit connexions were such that two adjacent sides of the lozenge were in parallel and two in series.

^ Thus, in the Crossley transmitter four hard carbon pencils were arranged in a lozenge -shaped figure, the ends of each pencil resting loosely in a small carbon block.

.These were supported at their ends in parallel carbon bars, which were carried by a nearly horizontal wooden diaphragm.^ These were supported at their ends in parallel carbon bars, which were carried by a nearly horizontal wooden diaphragm.

.Such multiple-electrode transmitters give a loud although somewhat harsh sound, and will bear being spoken to very strongly without breaking the circuit.^ Such multiple-electrode transmitters give a loud although somewhat harsh sound, and will bear being spoken to very strongly without breaking the circuit.

^ One of the electrodes was attached to a sounding board capable of being vibrated by sound-waves and the other was held either by springs or weights in delicate contact with it.

^ We need to bear in mind diseases such as MS and Alzheimer's are linked to proteins being found in the brain."
  • Cell Phones 31 January 2010 13:24 UTC tuberose.com [Source type: Academic]

.A type of transmitter which has come to be invaluable in connexion with long distance telephony, and which has practically superseded all other forms, is the granular carbon transmitter.^ A type of transmitter which has come to be invaluable in connexion with long distance telephony, and which has practically superseded all other forms, is the granular carbon transmitter.

^ This instrument has almost entirely displaced all other forms of transmitter.

^ The apparatus thus acted as both a transmitter and a receiver ; indeed it is essentially the magneto-receiver which has come into universal use in practical telephony, though for transmission it was soon superseded by forms of microphonic transmitters.

.The earliest instrument of this kind was the Hunnings transmitter, patented in 1878. This was constructed of a shallow box placed in a vertical position, with metallic front and back and insulating sides.^ The earliest instrument of this kind was the Hunnings transmitter, patented in 1878.

^ This was constructed of a shallow box placed in a vertical position, with metallic front and back and insulating sides.

^ The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.

.The front face was of thin metal, and served as a diaphragm.^ The front face was of thin metal, and served as a diaphragm.

^ D of thin sheet iron; in front of this was a cover M, M provided with a suitable cavity for directing the sound-waves against the diaphragm.

.The box was filled nearly, but not quite full, of granulated hard carbon.^ The box was filled nearly, but not quite full, of granulated hard carbon.

^ The space enclosed between the front and rear faces of the box is filled about three-quarters full of finely granulated hard carbon, which therefore lies in contact with the front and rear carbon disks of the apparatus, and also fills up the space lying between the lower edge of these disks and the curved surface of the case.

^ The front or cover of the case is a similar button of hard polished carbon D, also slightly smaller in diameter than the cylindrical wall of the box.

.The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.^ The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.

^ The current from the battery passes from one of the carbon disks to the other through the particles of granulated carbon which fill the space between them.

^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

.When spoken to the diaphragm vibrated, and thus set the carbon granules into vigorous vibration.^ When spoken to the diaphragm vibrated, and thus set the carbon granules into vigorous vibration.

^ He proposed to introduce into the circuit a cell containing carbon powder, the pressure on which could be varied by the micro- vibrations of a diaphragm.

^ The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.

.The vast number of microphonic contacts present give rise to very strong electrical undulations, and hence to a loud sound.^ The vast number of microphonic contacts present give rise to very strong electrical undulations, and hence to a loud sound.

^ In connexion with the present subject it is important to notice the three characteristics of a musical sound, namely, pitch , loudness and quality.

^ His aim was the production, by means of the undulations of pressure on a membrane caused by sound, of an electric current the strength of which should at every instant vary directly as the pressure varied).

.The chief difficulty with this transmitter, and with various others of later date based upon it, has been the frequent packing of the carbon granules, which renders the instrument inoperative.^ The chief difficulty with this transmitter, and with various others of later date based upon it, has been the frequent packing of the carbon granules, which renders the instrument inoperative.

^ The motions impressed upon the carbon granules are very vigorous, and this together with the particular arrangement of the parts of the instrument is effectual in obviating the difficulty from packing which attended the use of earlier forms of granulated carbon transmitters.

^ This instrument has almost entirely displaced all other forms of transmitter.

.The difficulty was first satisfactorily overcome in the long-distance transmitter, invented by A. C. White in the laboratory of the American Bell Telephone Company, and commonly known as the " solid back transmitter " (fig.^ The difficulty was first satisfactorily overcome in the long-distance transmitter, invented by A. C. White in the laboratory of the American Bell Telephone Company, and commonly known as the " solid back transmitter " (fig.

^ T-mobile was the first international communications company offering service to both the US and Europe and is well known for its ad campaigns featuring Catherine Zeta Jones.
  • T-Mobile To Go Prepaid Cell Phones | Prepaid Reviews 28 January 2010 1:30 UTC www.prepaidreviews.com [Source type: General]

^ In 1885 there were only 3800 telephone subscribers in London and less than io,000 in the rest of the United Kingdom, and telephonic services were available in only about 75 towns, while in the same year the American Bell Telephone Company had over 134,000 subscribers.

6).
.The microphonic portion of the transmitter is contained in a thin cylindrical box or case of brass A, the inner curved surface of which is covered with an insulating layer of paper.^ The microphonic portion of the transmitter is contained in a thin cylindrical box or case of brass A, the inner curved surface of which is covered with an insulating layer of paper.

^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

^ The separate wires are surrounded only with a loose covering of specially prepared paper, which furnishes abundant insulation.

.The case is firmly fixed to a " bridge " B with its back or bottom in a vertical position.^ The case is firmly fixed to a " bridge " B with its back or bottom in a vertical position.

^ This was constructed of a shallow box placed in a vertical position, with metallic front and back and insulating sides.

.To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.^ The front or cover of the case is a similar button of hard polished carbon D, also slightly smaller in diameter than the cylindrical wall of the box.

^ To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.

^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

.The front or cover of the case is a similar button of hard polished carbon D, also slightly smaller in diameter than the cylindrical wall of the box.^ The front or cover of the case is a similar button of hard polished carbon D, also slightly smaller in diameter than the cylindrical wall of the box.

^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

^ To the brass bottom of the case is attached 'a thin disk of polished hard carbon C, which is slightly less in diameter than the brass bottom, so that the carbon disk almost entirely covers this brass back, leaving only a slight annular space around its edge.

.It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet, and is capable of moving to and fro like a plunger when the diaphragm vibrates.^ It is attached to a brass disk E, which is fastened to the centre of the diaphragm F by means of a rivet , and is capable of moving to and fro like a plunger when the diaphragm vibrates.

^ The spring was attached to the centre of a diaphragm in such a way that, when the drum was turned, the friction between the point of the spring and the paper deflected !

^ Two disks of thin metal , or two stretched membranes, each furnished with a mouthpiece , are connected together by a thin string or wire attached at each end to the centres of the membranes.

.A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

^ The microphonic arrangement consisted of a spring S, about the hundredth of an inch thick and the eighth of an inch broad, fixed at one end to a lever L, and carrying at its free extremity a brass block W. In one side of W a small disk C of gas carbon was inserted, resting on the hemispherical end of a small platinum pin K, about the twentieth of an inch in diameter, held in position by a thin spring A. The pressure of the carbon on the platinum point could be adjusted by the screw N, which turned the lever about the flexible joint G. The electrical connexions of the instrument as arranged for actual use are also illustrated in the figure.

^ The microphonic portion of the transmitter is contained in a thin cylindrical box or case of brass A, the inner curved surface of which is covered with an insulating layer of paper.

.The box is thus entirely closed at the front, while the front carbon disk, which constitutes an electrode, is perfectly free to follow the motions of the diaphragm.^ The box is thus entirely closed at the front, while the front carbon disk, which constitutes an electrode, is perfectly free to follow the motions of the diaphragm.

^ The front or cover of the case is a similar button of hard polished carbon D, also slightly smaller in diameter than the cylindrical wall of the box.

.FIG. 6. - Solid Back Transmitter.^ The difficulty was first satisfactorily overcome in the long-distance transmitter, invented by A. C. White in the laboratory of the American Bell Telephone Company, and commonly known as the " solid back transmitter " (fig.

^ Solid Back Transmitter.

.The space enclosed between the front and rear faces of the box is filled about three-quarters full of finely granulated hard carbon, which therefore lies in contact with the front and rear carbon disks of the apparatus, and also fills up the space lying between the lower edge of these disks and the curved surface of the case.^ The box was filled nearly, but not quite full, of granulated hard carbon.

^ The space enclosed between the front and rear faces of the box is filled about three-quarters full of finely granulated hard carbon, which therefore lies in contact with the front and rear carbon disks of the apparatus, and also fills up the space lying between the lower edge of these disks and the curved surface of the case.

^ A washer of thin flexible mica G concentric with the carbon button is carried by the brass disk, and projecting over the edge of this is held firmly against the rim of the cylindrical wall of the case by an annular brass collar H, which is screwed upon the outer curved surface of this wall.

.The current from the battery passes from one of the carbon disks to the other through the particles of granulated carbon which fill the space between them.^ The current from the battery passes from one of the carbon disks to the other through the particles of granulated carbon which fill the space between them.

^ The current from the battery used passed from the diaphragm through the granulated carbon to the metallic back of the box.

^ When the current passed, the friction was felt to increase, and the effect of sending a rapidly undulating current through the arrangement was to produce a sound.

.The disks and granules constitute a very powerful microphone.^ The disks and granules constitute a very powerful microphone.

.The motions impressed upon the carbon granules are very vigorous, and this together with the particular arrangement of the parts of the instrument is effectual in obviating the difficulty from packing which attended the use of earlier forms of granulated carbon transmitters.^ The motions impressed upon the carbon granules are very vigorous, and this together with the particular arrangement of the parts of the instrument is effectual in obviating the difficulty from packing which attended the use of earlier forms of granulated carbon transmitters.

^ The chief difficulty with this transmitter, and with various others of later date based upon it, has been the frequent packing of the carbon granules, which renders the instrument inoperative.

^ This instrument has almost entirely displaced all other forms of transmitter.

.This instrument has almost entirely displaced all other forms of transmitter.^ This instrument has almost entirely displaced all other forms of transmitter.

^ A type of transmitter which has come to be invaluable in connexion with long distance telephony, and which has practically superseded all other forms, is the granular carbon transmitter.

^ The chief difficulty with this transmitter, and with various others of later date based upon it, has been the frequent packing of the carbon granules, which renders the instrument inoperative.

Table of contents

Subscribers' Organization

.The employment of the telephone as one of the great means of communication requires a definite organization of the subscribers.^ The employment of the telephone as one of the great means of communication requires a definite organization of the subscribers.

^ There is only one signal on the cord circuit at B, and that signal is controlled by exchange A. Each of the subscribers controls a signal at A, and when either or both of the telephones are replaced, the action is indicated by the lamps there.

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.It is not practicable to connect each subscriber directly to all the others, hence a system of exchanges has been adopted.^ It is not practicable to connect each subscriber directly to all the others, hence a system of exchanges has been adopted.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ Each subscriber's circuit is further connected to another spring-jack directly associated with the calling-drop.

.The territory in which a telephone administration operates is usually divided into a number of local areas, in each of which one or more exchanges are placed.^ The territory in which a telephone administration operates is usually divided into a number of local areas, in each of which one or more exchanges are placed.

^ When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."

^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

.An exchange is a central station to which wires are brought from the various subscribers in its neighbourhood, any two of whom can be put in telephonic communication with each other when the proper pairs of wires are joined together in the exchange.^ An exchange is a central station to which wires are brought from the various subscribers in its neighbourhood, any two of whom can be put in telephonic communication with each other when the proper pairs of wires are joined together in the exchange.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.

.When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

^ When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."

^ The territory in which a telephone administration operates is usually divided into a number of local areas, in each of which one or more exchanges are placed.

.In some cases the exchanges are connected together directly; but when the volume of traffic is not sufficient to warrant the adoption of such a course connexions between two exchanges are made through junction centres to which both are connected.^ In some cases the exchanges are connected together directly; but when the volume of traffic is not sufficient to warrant the adoption of such a course connexions between two exchanges are made through junction centres to which both are connected.

^ Sporting both 2.7- and 1.7-inch screens, the phone offers tri-band GSM connectivity, two megapixel camera, and GPS. HTC Touch Pro -- Jun.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ The circuit connexions were such that two adjacent sides of the lozenge were in parallel and two in series.

.A system of wires, similar to that which connects the district exchanges in an area, links together the various local areas in the territory, and sometimes the territory of one administration with that of another.^ A system of wires, similar to that which connects the district exchanges in an area, links together the various local areas in the territory, and sometimes the territory of one administration with that of another.

^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

^ When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."

.These inter-area or long-distance lines, called trunk circuits in England, terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

^ These areas are called cells.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ During the progress of these operations the A operator connects the originating subscriber to the junction circuit named by the B operator.

Circuit and Working Arrangements

.The method first employed for working a telephone line was extremely simple.^ The method first employed for working a telephone line was extremely simple.

^ The Hush-A-Phone was a simple product that slipped over a Candlestick Phone or Telephone Handset and gave the user some privacy (the first noise canceling microphone!
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ As no practical process of telephone relaying has been devised, it is extremely important that the character of the line should be such as to favour the preservation of the strength and form of the telephone current.

.A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.^ A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal .

.Words spoken to the telephone at one end could be heard by holding the telephone to the ear at the other.^ Words spoken to the telephone at one end could be heard by holding the telephone to the ear at the other.

^ The radios were half-duplex, this is to say, you could talk or listen, one or the other.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.To obviate the inconvenience of placing the telephone to the mouth and the ear alternately, two telephones were commonly used at each end, joined either parallel to each other or in series.^ To obviate the inconvenience of placing the telephone to the mouth and the ear alternately, two telephones were commonly used at each end, joined either parallel to each other or in series.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal .

.The contrivance most generally adopted for calling attention was a call-bell rung either by a small magneto-electric machine (magneto-generator) or by a battery.^ Works for phones, texting, or just generally not paying attention to the multi-ton machine you're controlling while it hurtles down the road.
  • Slashdot | The Cell Phone Has Changed — New Etiquette Needed 31 January 2010 13:24 UTC slashdot.org [Source type: FILTERED WITH BAYES]

.The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal.^ The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal .

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.This arrangement is still employed, a hook being attached to the switch lever so that the mere hanging up of the telephone puts the bell in circuit.^ This arrangement is still employed, a hook being attached to the switch lever so that the mere hanging up of the telephone puts the bell in circuit.

^ A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.

^ The telephone was switched out of circuit when not in use and the bell put in its place, a key being used for throwing the battery into circuit to make the signal .

.In some cases when a magneto-generator is employed for calling purposes the coil of the machine is automatically cut out of circuit when it is not in action, and is brought into circuit when the handle is turned by the operation of a centrifugal or other arrangement.^ In some cases when a magneto-generator is employed for calling purposes the coil of the machine is automatically cut out of circuit when it is not in action, and is brought into circuit when the handle is turned by the operation of a centrifugal or other arrangement.

^ Though many types of manually operated switchboards have been brought into use, differing from each other in respect of circuit and working arrangements, yet each of them may be placed in one or other of three main classes according as the system of working is magneto, call-wire, or common battery.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

.At first it was usual to join the microphone transmitter in the direct circuit.^ At first it was usual to join the microphone transmitter in the direct circuit.

^ The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.

.It was soon found that it could only be used to advantage in this way when the total resistance of the circuit, exclusive of the microphone, was small compared with the resistance of the microphone - that is, on very short lines worked with FIG. 7. - Telephone Set with Transmitter in a Local Circuit.^ It was soon found that it could only be used to advantage in this way when the total resistance of the circuit, exclusive of the microphone, was small compared with the resistance of the microphone - that is, on very short lines worked with FIG. 7.

^ Oliver Heaviside showed mathematically that uniformly-distributed inductance in a telephone line would diminish both attenuation and distortion, and that if the inductance were great enough and the insulation resistance not too high the circuit would be distortionless, while currents of all frequencies would be equally attenuated.

^ The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire.

low resistance telephones. .The transmitter on long and high resistance lines worked better by joining, in the manner shown in fig.^ The transmitter on long and high resistance lines worked better by joining, in the manner shown in fig.

^ It was soon found that it could only be used to advantage in this way when the total resistance of the circuit, exclusive of the microphone, was small compared with the resistance of the microphone - that is, on very short lines worked with FIG. 7.

^ The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.

.7, the microphone, a battery and the primary of an induction coil in a local circuit, and putting the line in circuit with the secondary of the induction coil, which acted as the transmitter.^ The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.

^ The transmitter is placed in multiple with the primary winding of an induction coil whose secondary operates in the loop circuit, and consequently when the transmitter is spoken into, a variable E.M.F. is impressed upon the circuit through the medium of the induction coil.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

.The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire.^ The resistance of the microphone can thus be made a large fraction of the total resistance of the circuit in which it is placed; hence by using considerable currents, small variations in its resistance can be made to induce somewhat powerful currents in the line wire.

^ Hence, when the undulating telephonic currents were made to pass through the apparatus, the constant variation of the friction of the spring caused the deflexions of the diaphragm to vary in unison with the variation of the electric The extreme smallness of the magnets which might be successfully employed was first demonstrated by Professor Peirce of Brown University, Providence , R.I. .

^ Oliver Heaviside showed mathematically that uniformly-distributed inductance in a telephone line would diminish both attenuation and distortion, and that if the inductance were great enough and the insulation resistance not too high the circuit would be distortionless, while currents of all frequencies would be equally attenuated.

.The requisite energy is derived from the battery.^ The requisite energy is derived from the battery.

.In the earliest telephone switchboards the lines were connected to vertical conducting strips, across which were placed a series of similar horizontal strips in such a manner that any horizontal could be connected to any line strip by the insertion of a plug into holes provided in the strips for the purpose.^ In the earliest telephone switchboards the lines were connected to vertical conducting strips, across which were placed a series of similar horizontal strips in such a manner that any horizontal could be connected to any line strip by the insertion of a plug into holes provided in the strips for the purpose.

^ Any two lines could be connected together by connecting both to the same horizontal strip.

^ Various states already have such laws in place, as well as certain cities across the country.

.Any two lines could be connected together by connecting both to the same horizontal strip.^ Any two lines could be connected together by connecting both to the same horizontal strip.

^ Sporting both 2.7- and 1.7-inch screens, the phone offers tri-band GSM connectivity, two megapixel camera, and GPS. HTC Touch Pro -- Jun.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ In some cases the exchanges are connected together directly; but when the volume of traffic is not sufficient to warrant the adoption of such a course connexions between two exchanges are made through junction centres to which both are connected.

.The next step of importance was the introduction of what was termed the " Standard board."^ The next step of importance was the introduction of what was termed the " Standard board."

.This board was equipped with spring-jacks and annunciators (calling-drops) for the subscribers' lines, and with flexible cords terminating in plugs for connecting purposes.^ Interesting Switchboard with only two positions with cords, but a third position with jacks for subscribers on the far right (used by right set of cords).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ Click for a bigger photo of the Drops (used for incoming calls instead of a lamp), and connections on the Magneto Test Desk .
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ In the beginning, you couldn't even call someone who was a subscriber in the competing system, since the lines didn't connect anywhere.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.The spring-jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ As subscribers' lines are invariably short, the smallest gauge of wire possessing the mechanical strength necessary to withstand the stresses to which it may be subjected can be employed, and bronze wire weighing 40 lb per mile is commonly used.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

.When a plug was inserted in the spring-jack the connexion between the springs was opened, disconnecting the calling-drop from the line.^ When a plug was inserted in the spring-jack the connexion between the springs was opened, disconnecting the calling-drop from the line.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

^ This attracted the attention of the attendant, who in response to the call inserted a plug into the spring-jack and connected the speaking apparatus to the circuit by means of the key.

.Each connecting-cord circuit had associated with it a clearing-out drop connected between the cord and earth and a key by means of which the operator's speaking and ringing apparatus could be brought into circuit.^ Each connecting- cord circuit had associated with it a clearing-out drop connected between the cord and earth and a key by means of which the operator's speaking and ringing apparatus could be brought into circuit.

^ In the first place it increased the visibility of the signalling instrument; in the second place it brought that instrument into the position in which it could most readily catch the operator's eye; and finally it eliminated the effort involved in associating one piece of apparatus with another and in finding that other.

^ This attracted the attention of the attendant, who in response to the call inserted a plug into the spring-jack and connected the speaking apparatus to the circuit by means of the key.

.When a subscriber called (by turning the handle of his magneto- 'generator), the shutter of the annunciator associated with his line dropped.^ When a subscriber called (by turning the handle of his magneto- 'generator), the shutter of the annunciator associated with his line dropped.

^ The callingdrop of the magneto system was displaced by a relay and a small electric incandescent lamp , and whereas in the older system the calling-drop and the answering jack with which it was associated were some distance apart, the calling-lamp and the answering jack of the newer system were placed in juxtaposition.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

.This attracted the attention of the attendant, who in response to the call inserted a plug into the spring-jack and connected the speaking apparatus to the circuit by means of the key.^ This attracted the attention of the attendant, who in response to the call inserted a plug into the spring-jack and connected the speaking apparatus to the circuit by means of the key.

^ The operator, whose attention is thus attracted, inserts a peg in the jack, then throws over the speaking key of the cord circuit, and having ascertained particulars of the requirement places the other peg of the pair in the nearest multiple jack of the wanted subscriber, whom she proceeds to ring up.

^ Each connecting- cord circuit had associated with it a clearing-out drop connected between the cord and earth and a key by means of which the operator's speaking and ringing apparatus could be brought into circuit.

.Then, having obtained particulars of the subscriber's requirement, the operator connected the second plug to the spring-jack of the wanted subscriber, whom she rang up.^ Then, having obtained particulars of the subscriber's requirement, the operator connected the second plug to the spring-jack of the wanted subscriber, whom she rang up.

^ The operator, whose attention is thus attracted, inserts a peg in the jack, then throws over the speaking key of the cord circuit, and having ascertained particulars of the requirement places the other peg of the pair in the nearest multiple jack of the wanted subscriber, whom she proceeds to ring up.

^ The supervisory lamp associated with the peg in the wanted subscriber's jack glows from the time that the peg is inserted until the subscriber responds, when it darkens, in which condition it remains until the subscriber restores the receiver to the hook and causes the lamp to light up again.

When. the conversation was finished either of the subscribers could release the shutter of the clearing-out drop by turning his generator handle, and the operator thus notified of the fact removed the plugs and discontinued the connexion.
.The single-wire earthed circuits used in the early days of telephony were subject to serious disturbances from the induction caused by currents in neighbouring telegraph and electric light wires, and from the varying potential of the earth due to natural or artificial causes.^ The single-wire earthed circuits used in the early days of telephony were subject to serious disturbances from the induction caused by currents in neighbouring telegraph and electric light wires, and from the varying potential of the earth due to natural or artificial causes.

^ It was early recognized that a complete metallic circuit would obviate troubles from varying earth potentials, and that if the outgoing and incoming branches of the circuit were parallel and kept, by transposition spiralling, or otherwise, at equal average distances from the disturbing wire, induction effects would likewise be removed.

^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The introduction of electric tramways caused an enormous increase in disturbances of this class.^ The introduction of electric tramways caused an enormous increase in disturbances of this class.

.It was early recognized that a complete metallic circuit would obviate troubles from varying earth potentials, and that if the outgoing and incoming branches of the circuit were parallel and kept, by transposition spiralling, or otherwise, at equal average distances from the disturbing wire, induction effects would likewise be removed.^ It was early recognized that a complete metallic circuit would obviate troubles from varying earth potentials, and that if the outgoing and incoming branches of the circuit were parallel and kept, by transposition spiralling, or otherwise, at equal average distances from the disturbing wire, induction effects would likewise be removed.

^ After the withdrawal of the restriction against the companies erecting trunk wires it became evident that the development of the telephone services throughout the country would be facilitated by complete intercommunication and uniformity of systems, and that economies could be effected by concentration of management.

^ The single-wire earthed circuits used in the early days of telephony were subject to serious disturbances from the induction caused by currents in neighbouring telegraph and electric light wires, and from the varying potential of the earth due to natural or artificial causes.

These advantages led to the gradual supersession of the single-wire system until at the present day the all-metallic system is employed almost universally. Since the time when the system first became prominent all switchboards have been arranged for metallic circuits.
.Though many types of manually operated switchboards have been brought into use, differing from each other in respect of circuit and working arrangements, yet each of them may be placed in one or other of three main classes according as the system of working is magneto, call-wire, or common battery.^ The " call-wire " system has been used to some extent, but it is now obsolete.

^ Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.

^ Though many types of manually operated switchboards have been brought into use, differing from each other in respect of circuit and working arrangements, yet each of them may be placed in one or other of three main classes according as the system of working is magneto, call-wire, or common battery.

.The fundamental principle of the magneto system has been described in connexion with the " Standard board."^ The fundamental principle of the magneto system has been described in connexion with the " Standard board."

.In a large exchange a number of operators are necessary to attend to calls.^ In a large exchange a number of operators are necessary to attend to calls.

^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

^ In large towns served by a number of exchanges the junction equipment is an important feature.

.Several single switchboards like that described may be employed, each devoted to a certain section of the subscribers, and placed in care of an operator.^ Several single switchboards like that described may be employed, each devoted to a certain section of the subscribers, and placed in care of an operator.

^ As we've discussed, TDMA or time division multiple access, places several calls on a single frequency.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ May 19, 2006 at 5:52 am *On the internet, people can pretend to be anything they want to… like a Strand employ, as someone else already mentioned.
  • Cell Phone Symphony « Improv Everywhere 31 January 2010 13:24 UTC improveverywhere.com [Source type: General]

.In these circumstances, when, as frequently will be the case, the person calling desires to be put in communication with a subscriber who belongs to another section, connexions must be established in the office between the two sections; this necessitates additional switchboard arrangements, and also increases the time required to put subscribers in communication with one another.^ In time division multiple access we separate calls by time, one after another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In these circumstances, when, as frequently will be the case, the person calling desires to be put in communication with a subscriber who belongs to another section, connexions must be established in the office between the two sections; this necessitates additional switchboard arrangements, and also increases the time required to put subscribers in communication with one another.

^ Hence this operator, when signalled in the ordinary way, can put any one of these subscribers in connexion with any subscriber whatever, without the necessity of calling upon another operator to make connexions.

.The difficulty was obviated by the introduction of the " multiple switchboard."^ The difficulty was obviated by the introduction of the " multiple switchboard."

.This board is built up in sections of one or more operators' positions each.^ When there were multiple positions that weren't covered by operators (like at night), an operator could use a plug from her switchboard in a jack of one on either side.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.All the subscribers' lines are connected in order to jacks on the first two or three or four operators' positions, and these connexions are repeated or " multipled " upon each succeeding similar group of positions.^ Interesting Switchboard with only two positions with cords, but a third position with jacks for subscribers on the far right (used by right set of cords).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ Africa showed the greatest increase, and more than two-thirds of all cell phone subscribers now come from developing countries.
  • Cell Phones 31 January 2010 13:24 UTC tuberose.com [Source type: Academic]

^ When businesses began installing multiple phones within their buildings, an on-site switchboard was used to connect a particular phone to an outside line.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.Each subscriber's circuit is further connected to another spring-jack directly associated with the calling-drop.^ Click for a bigger photo of the Drops (used for incoming calls instead of a lamp), and connections on the Magneto Test Desk .
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ In the beginning, you couldn't even call someone who was a subscriber in the competing system, since the lines didn't connect anywhere.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ The plugs, combined with their associated switches, were what actually rang and connected telephones (the jacks).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.These springjacks, known as answering jacks, are distributed along the switchboard, a certain number being terminated upon each position and placed in the care of the operator assigned to that position.^ These springjacks, known as answering jacks, are distributed along the switchboard, a certain number being terminated upon each position and placed in the care of the operator assigned to that position.

^ These supervisory signals took the form of lamps and were placed on the keyboard in positions immediately adjacent to the associated cords.

^ When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."

.Hence this operator, when signalled in the ordinary way, can put any one of these subscribers in connexion with any subscriber whatever, without the necessity of calling upon another operator to make connexions.^ Hence this operator, when signalled in the ordinary way, can put any one of these subscribers in connexion with any subscriber whatever, without the necessity of calling upon another operator to make connexions.

^ In these circumstances, when, as frequently will be the case, the person calling desires to be put in communication with a subscriber who belongs to another section, connexions must be established in the office between the two sections; this necessitates additional switchboard arrangements, and also increases the time required to put subscribers in communication with one another.

^ The system of the British Post Office is worked as follows: A subscriber desiring a long-distance connexion calls up his local exchange in the ordinary way, and the operator there, being informed that a trunk connexion is desired, extends the subscriber's line to the Post Office by means of a record circuit.

.Two methods of " multipling " have been much used.^ Two methods of " multipling " have been much used.

^ Another type of microphone which was used in Europe much more than in the United States was the multiple-contact instrument.

^ Another access method is code division multiple access or CDMA. The cellular system that uses it, IS-95, tags each and every part of multiple conversations with a specific digital code.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In the arrangement first introduced the line wire is connected in series through the various spring-jacks, the circuit finally passing through the answering jack to the calling-drop.^ Each subscriber's circuit is further connected to another spring-jack directly associated with the calling-drop.

^ This arrangement permits particulars of calls to be passed over lines while conversations are in progress.

^ In this arrangement, instead of the circuit being made through the jacks in series, each jack is connected to an independent branch from the main circuit.

.This arrangement is liable to give trouble, as disconnexions may arise in the spring-jacks in consequence of the failures of the springs to make contact.^ This arrangement is liable to give trouble, as disconnexions may arise in the spring-jacks in consequence of the failures of the springs to make contact.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ In the arrangement first introduced the line wire is connected in series through the various spring-jacks, the circuit finally passing through the answering jack to the calling-drop.

.Operating mistakes also cause interruptions to conversations, as it is possible, by the insertion of a plug in a multiple jack, to disconnect the circuit between two talking subscribers.^ Operating mistakes also cause interruptions to conversations, as it is possible, by the insertion of a plug in a multiple jack, to disconnect the circuit between two talking subscribers.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

^ The call is controlled by the trunk operators, the junction circuits being equipped in such a manner that the subscribers' signals appear at the trunk exchanges, from which point disconnecting signals are sent automatically to the local exchanges, when the connexions between the trunk and the junction circuits are removed.

.To overcome these difficulties the " branching multiple " was introduced.^ To overcome these difficulties the " branching multiple " was introduced.

^ With the " branching multiple " the " selfrestoring drop " was introduced.

In this arrangement, instead of the circuit being made through the jacks in series, each jack is connected to an independent branch from the main circuit. .With the " branching multiple " the " selfrestoring drop " was introduced.^ To overcome these difficulties the " branching multiple " was introduced.

^ With the " branching multiple " the " selfrestoring drop " was introduced.

.This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

.It is necessary that the operators working at a multiple board shall be able to ascertain without entering a subscriber's circuit whether the circuit be disengaged.^ It is necessary that the operators working at a multiple board shall be able to ascertain without entering a subscriber's circuit whether the circuit be disengaged.

^ Operating mistakes also cause interruptions to conversations, as it is possible, by the insertion of a plug in a multiple jack, to disconnect the circuit between two talking subscribers.

^ Each subscriber's circuit on this system terminates upon the incoming portion of a selector switch, called a first selector, and is multipled upon the outgoing portions of a number of similar switches called connector switches.

.This requirement is usually met by connecting a third or " test " wire to each of the jacks associated with a subscriber's line, and by making the circuit arrangements such that this wire is either disconnected or at earth potential when the line is not in use, and at some potential above or below that of the earth, when the circuit is engaged.^ This requirement is usually met by connecting a third or " test " wire to each of the jacks associated with a subscriber's line, and by making the circuit arrangements such that this wire is either disconnected or at earth potential when the line is not in use, and at some potential above or below that of the earth, when the circuit is engaged.

^ In addition to its durability, the writer has found that this type of clip is in some respects a great deal more convenient to rise than the "suspender clip" frequently furnished with the test sets for making attachment to wires.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ As subscribers' lines are invariably short, the smallest gauge of wire possessing the mechanical strength necessary to withstand the stresses to which it may be subjected can be employed, and bronze wire weighing 40 lb per mile is commonly used.

.With a proper arrangement of the operator's speaking set it is possible, by touching the socket of a jack with the tip of a peg or a special " test " thimble, to determine whether the circuit connected to the jack is in use.^ With a proper arrangement of the operator's speaking set it is possible, by touching the socket of a jack with the tip of a peg or a special " test " thimble , to determine whether the circuit connected to the jack is in use.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ Each subscriber's circuit is further connected to another spring-jack directly associated with the calling-drop.

.Both the series and the branching methods of multipling are recognized at the present time as standard methods, although the former is only employed in comparatively small exchanges.^ Both the series and the branching methods of multipling are recognized at the present time as standard methods, although the former is only employed in comparatively small exchanges.

^ In consequence of their high capacity, the attenuation constant of submarine cables is high, and only a small number of cables, of comparatively short length, are in use for telephonic purposes.

^ Although called 'multiple access', it is really another multiplexing method, a way to put many calls at once on a single channel.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The magneto system itself is dying out.^ The magneto system itself is dying out.

.There are still many magneto exchanges in existence, but when new exchanges are erected only the very smallest are equipped for magneto working, that system having succumbed to the common battery one in the case of all equipments of moderate and large dimensions.^ There are still many magneto exchanges in existence, but when new exchanges are erected only the very smallest are equipped for magneto working, that system having succumbed to the common battery one in the case of all equipments of moderate and large dimensions.

^ Though many types of manually operated switchboards have been brought into use, differing from each other in respect of circuit and working arrangements, yet each of them may be placed in one or other of three main classes according as the system of working is magneto, call-wire, or common battery.

^ Hull and Portsmouth were the only municipal telephone systems working in 1907.

"low
.The " call-wire " system has been used to some extent, but it is now obsolete.^ The " call-wire " system has been used to some extent, but it is now obsolete.

^ Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.

^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

.The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

^ These inter-area or long-distance lines, called trunk circuits in England , terminate at one exchange in each local area, and between that exchange and the various district exchanges junction circuits are provided for the purpose of connecting subscribers to the trunk lines.

^ The system of the British Post Office is worked as follows: A subscriber desiring a long-distance connexion calls up his local exchange in the ordinary way, and the operator there, being informed that a trunk connexion is desired, extends the subscriber's line to the Post Office by means of a record circuit.

.Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.^ The " call-wire " system has been used to some extent, but it is now obsolete.

^ Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

.Each telephone set was equipped with a special key or switch by means of which the telephone could be transferred from an exclusive line to the call-wire at will.^ Each telephone set was equipped with a special key or switch by means of which the telephone could be transferred from an exclusive line to the call-wire at will.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ A single line of wire, like an ordinary telegraph line, had a Bell telephone included in it at each end, and the ends were put to earth.

.A subscriber desiring a connexion pressed the key and communicated his own number and that of the wanted subscriber to the operator in attendance on the call-wire.^ A subscriber desiring a connexion pressed the key and communicated his own number and that of the wanted subscriber to the operator in attendance on the call-wire.

^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ Each subscriber's circuit on this system terminates upon the incoming portion of a selector switch, called a first selector, and is multipled upon the outgoing portions of a number of similar switches called connector switches.

.Then, when the connexion was made, the originating subscriber rang up the other.^ Then, when the connexion was made, the originating subscriber rang up the other.

^ Then, having obtained particulars of the subscriber's requirement, the operator connected the second plug to the spring-jack of the wanted subscriber, whom she rang up.

^ At the close of a conversation the originating subscriber again entered the call-wire and requested the operator to take down the connexion.

.At the close of a conversation the originating subscriber again entered the call-wire and requested the operator to take down the connexion.^ At the close of a conversation the originating subscriber again entered the call-wire and requested the operator to take down the connexion.

^ During the progress of these operations the A operator connects the originating subscriber to the junction circuit named by the B operator.

^ The call is controlled by the trunk operators, the junction circuits being equipped in such a manner that the subscribers' signals appear at the trunk exchanges, from which point disconnecting signals are sent automatically to the local exchanges, when the connexions between the trunk and the junction circuits are removed.

.The call-wires were usually equipped with drops in order that the exchange might be called at night when the operators were not listening continuously.^ The call-wires were usually equipped with drops in order that the exchange might be called at night when the operators were not listening continuously.

^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

^ Each telephone set was equipped with a special key or switch by means of which the telephone could be transferred from an exclusive line to the call-wire at will.

.One of the greatest advances made in the development of the art of telephony was the introduction of the " common battery relay system."^ One of the greatest advances made in the development of the art of telephony was the introduction of the " common battery relay system."

^ There are still many magneto exchanges in existence, but when new exchanges are erected only the very smallest are equipped for magneto working, that system having succumbed to the common battery one in the case of all equipments of moderate and large dimensions.

^ Stone Common Battery System.

.This advance did not merely remove the primary batteries from the subscribers' stations; it removed also the magneto-generator, and at the same time it modified considerably the conditions governing the exchange operating.^ This advance did not merely remove the primary batteries from the subscribers' stations; it removed also the magneto-generator, and at the same time it modified considerably the conditions governing the exchange operating.

^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

^ The record operator then removes her speaking apparatus from the circuit, and the local operator, receiving a disconnect signal, severs the connexion at the local exchange.

.The callingdrop of the magneto system was displaced by a relay and a small electric incandescent lamp, and whereas in the older system the calling-drop and the answering jack with which it was associated were some distance apart, the calling-lamp and the answering jack of the newer system were placed in juxtaposition.^ The callingdrop of the magneto system was displaced by a relay and a small electric incandescent lamp , and whereas in the older system the calling-drop and the answering jack with which it was associated were some distance apart, the calling-lamp and the answering jack of the newer system were placed in juxtaposition.

^ Each subscriber's circuit is further connected to another spring-jack directly associated with the calling-drop.

^ When a plug was inserted in the spring-jack the connexion between the springs was opened, disconnecting the calling-drop from the line.

.This alteration improved the operating conditions in three ways.^ This alteration improved the operating conditions in three ways.

.In the first place it increased the visibility of the signalling instrument; in the second place it brought that instrument into the position in which it could most readily catch the operator's eye; and finally it eliminated the effort involved in associating one piece of apparatus with another and in finding that other.^ In the first place it increased the visibility of the signalling instrument; in the second place it brought that instrument into the position in which it could most readily catch the operator's eye; and finally it eliminated the effort involved in associating one piece of apparatus with another and in finding that other.

^ Each connexion involves the use of three switches, viz., a first selector, a connector switch, and a second selector which is brought into operation between the other two.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

.Moreover the clearing-out drop of the cord circuit was replaced by an arrangement which included the provision of one signal to be controlled through the agency of a relay by the calling subscriber, and another to be controlled by the person wanted.^ Moreover the clearing-out drop of the cord circuit was replaced by an arrangement which included the provision of one signal to be controlled through the agency of a relay by the calling subscriber, and another to be controlled by the person wanted.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

^ There is only one signal on the cord circuit at B, and that signal is controlled by exchange A. Each of the subscribers controls a signal at A, and when either or both of the telephones are replaced, the action is indicated by the lamps there.

.These supervisory signals took the form of lamps and were placed on the keyboard in positions immediately adjacent to the associated cords.^ These supervisory signals took the form of lamps and were placed on the keyboard in positions immediately adjacent to the associated cords.

^ There is only one signal on the cord circuit at B, and that signal is controlled by exchange A. Each of the subscribers controls a signal at A, and when either or both of the telephones are replaced, the action is indicated by the lamps there.

^ These springjacks, known as answering jacks, are distributed along the switchboard, a certain number being terminated upon each position and placed in the care of the operator assigned to that position.

.With the adoption of relays the signalling between the subscribers and the exchange became automatic, and, with the introduction of the principle of double and automatic supervision on the cord circuits, it became possible for the operators to tell at any instant the state of a connexion.^ With the adoption of relays the signalling between the subscribers and the exchange became automatic, and, with the introduction of the principle of double and automatic supervision on the cord circuits, it became possible for the operators to tell at any instant the state of a connexion.

^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

^ The call is controlled by the trunk operators, the junction circuits being equipped in such a manner that the subscribers' signals appear at the trunk exchanges, from which point disconnecting signals are sent automatically to the local exchanges, when the connexions between the trunk and the junction circuits are removed.

.As a result the time occupied by an operator per call was reduced from 50.77 seconds to 16.63 seconds.^ As a result the time occupied by an operator per call was reduced from 50.77 seconds to 16.63 seconds.

^ But you can go through their operator and pay three times the cost of a normal call if you like.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ As the Cellular Development group puts it, "A CDMA call starts with a standard rate of 9600 bits per second (9.6 kilobits per second).
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Threefundamental common battery transmissionsystemshavebeen devised and are shown in figs.^ Threefundamental common battery transmissionsystemshavebeen devised and are shown in figs.

.8, 9 and 10. In the Hayes system (fig.^ In the Hayes system (fig.

.8) a repeating coil is placed in the cord circuit, and when two subscribers are connected together the winding connected to the line of the subscriber who is talking for the time being acts as primary, and the other, which is in the line of the listening subscriber, as secondary.^ In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

^ When the subscribers in a local area exceed a certain number, or when for some other reason it is not convenient or economical to connect all the subscribers in the area to one exchange, it is usual to divide the area into a number of districts in each of which an exchange is placed, and to connect these district exchanges together by means of " junction circuits."

.Exchange From the Post Office Electrical Engineers' Journal. FIG. 8. - Hayes Common Battery System.^ Threefundamental common battery transmissionsystemshavebeen devised and are shown in figs.

^ There are still many magneto exchanges in existence, but when new exchanges are erected only the very smallest are equipped for magneto working, that system having succumbed to the common battery one in the case of all equipments of moderate and large dimensions.

^ The Post Office at the same time established several telephone exchanges in provincial towns so as to enable the PostmasterGeneral " to negotiate with the telephone companies in a satisfactory manner for licences."

.The Stone system (fig.^ The Stone system (fig.

.9) is characterized by the use of impedance coils between the battery and the line wires.^ This allocation is split equally between wire-line and radio common carriers (each is allocated 333 channels).
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A small snap with saw-tooth jaws frequently catches when the lineman is climbing between the wires, or when being removed from the line, and causes annoyance.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.When one of two subscribers connected together by this arrangement talks, the Exchange From the Post Office Electrical Engineers' Journal. FIG. 9. - Stone Common Battery System.^ The Stone system (fig.

^ When one of two subscribers connected together by this arrangement talks, the Exchange From the Post Office Electrical Engineers' Journal.

^ In 1831 Wheatstone by his " magic lyre " experiment showed that, when the sounding -boards of two musical instruments are connected together by a rod of pine wood, a tune played on one will be faithfully reproduced by the other.

variation in resistance of the transmitter spoken into causes a variation of the pressure at the line terminals of the impedance coils, and since those terminals are common to the two circuits the variable E.M.F. operates in the line of the listening subscriber, causing the reproduction of the speech in the latter's receiver. The Stone system, compared with that of Hayes, possesses the Exchanc 1.
Missing image
Telephone-5.jpg
.'1. .1 From the Post Office Electrical Engineers' Journal. FIG. to.^ Exchange From the Post Office Electrical Engineers' Journal.

^ From the Post Office Electrical Engineers' Journal.

^ When one of two subscribers connected together by this arrangement talks, the Exchange From the Post Office Electrical Engineers' Journal.

- Dean Common Battery System.
Missing image
Telephone-6.jpg
Missing image
Telephone-7.jpg
Missing image
Telephone-8.jpg
Missing image
Telephone-9.jpg
Missing image
Telephone-10.jpg
disadvantage that one of the conditions affecting the supply of current to any particular subscriber's circuit is the resistance of the .Subscriber'S Office c FIG. 1 i.^ Missing image Telephone-6.jpg Missing image Telephone-7.jpg Missing image Telephone-8.jpg Missing image Telephone-9.jpg Missing image Telephone-10.jpg disadvantage that one of the conditions affecting the supply of current to any particular subscriber's circuit is the resistance of the Subscriber'S Office c FIG. 1 i.

- .Subscriber's Circuit, Common Battery System.^ Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.

^ The feature of the system was the provision of special service circuits, termed call-wires, for purposes of communication between the subscribers and the exchange operators.

^ Dean Common Battery System.

other circuit to which it is connected for the time being. .An improvement in this respect has been effected by the insertion of condensers in the cord circuits, coupled with the use of two sets of impedance coils, one set on each.^ An improvement in this respect has been effected by the insertion of condensers in the cord circuits, coupled with the use of two sets of impedance coils, one set on each.

^ A cord circuit, similar in many respects, including the method .y.^9 Jr '' of operation, but equipped with condensers and impedance coils, in place of the repeating coil, is shown in fig.

^ This apparatus has two coils, one of which, connected across the line, is provided for the purpose of projecting the shutter, while the other is intended for its restoration and is joined in a local circuit arranged to be closed when a plug is inserted in any one of the associated jacks.

side of the condensers.
Missing image
Telephone-11.jpg
.Dean's method (fig.^ Missing image Telephone-11.jpg Dean's method (fig.

.50) embodies the idea of supplying current to the transmitters over the line wires in parallel instead of round the loop circuit, as in the other systems referred to.^ The spring- jack used was a form of switch with two contact springs which pressed against each other, one being connected to the subscriber's line wire and the other to the annunciator, which was also earthed.

^ The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.

^ Each subscriber was given the exclusive use of a circuit as in other systems, and shared a call-wire with a number of other subscribers.

An earth return is used. The transmitter is placed in multiple with the primary winding of an induction coil whose secondary operates in the loop circuit, and consequently when the transmitter is spoken into, a variable E.M.F. is impressed upon the circuit through the medium of the induction coil. .The impedance coils shown connected between the battery and the lines and between the latter and the transmitters are joined up non-inductively as regards the transmitter circuits, but inductively as regards the secondary circuits.^ You MUST connect a .47mf 100V non-polar capacitor in-series with this lamp (we also stock these), or it will answer the line by itself!
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

Figs. .II and 12 indicate typical subscriber's and connecting-cord circuits as equipped by the Western Electric Company.^ Switchboards were originally located at telephone company Central Offices, and were used to connect subscribers together so they could talk.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.At the subscriber's station when the receiver is on the hook switch the circuit is through the call-bell and a condenser.^ The base station serving your call sends a hand-off request to the mobile switch after your signal drops below a handover threshold.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The conditions permit of the circulation of the alternating currents of low periodicity, which are used for operating the bells, but in respect of the battery the circuit is open until the subscriber lifts the receiver, when the hook switch, thus released, joins the transmitter with one winding of an induction coil in series across the circuit.^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ When there were multiple positions that weren't covered by operators (like at night), an operator could use a plug from her switchboard in a jack of one on either side.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ "Talk/Monitor" switch in the unit, and put in a modern T-1 transmitter and U-1 receiver.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.A current then flows and in passing round the circuit operates the line relay, with the result that the calling-lamp is lighted.^ This lamp is neat, because it will light when the line is ringing.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ When used for Message Waiting, the lamp also lights when the line is ringing.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ I wrote in passing about how increasing call capacity was the chief benefit of TDMA to cellular operators.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The operator, whose attention is thus attracted, inserts a peg in the jack, then throws over the speaking key of the cord circuit, and having ascertained particulars of the requirement places the other peg of the pair in the nearest multiple jack of the wanted subscriber, whom she proceeds to ring up.^ Interesting Switchboard with only two positions with cords, but a third position with jacks for subscribers on the far right (used by right set of cords).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ A telegraph key tap broke the circuit momentarily, transmitting a short pulse to a distant sounder, interpreted by an operator as a dot.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ When there were multiple positions that weren't covered by operators (like at night), an operator could use a plug from her switchboard in a jack of one on either side.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.In the meantime the callinglamp has darkened; and each subscriber's line being equipped with a cut-off relay whose function it is to disconnect tl, e calling apparatus while the circuit is in use, the insertion o r a peg is immediately followed by the disappearance of the calling signal.^ Landline telegraphs used a key to make or break an electrical circuit, a battery to produce power, a single line joining one telegraph station to another and an electromagnetic receiver or sounder that upon being turned on and off, produced a clicking noise.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Even so, there are still some crackpots using this type of phone system (or Centrex) with single line phones, and they just tell you to "Call back if I cut you off while transferring you."
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

The supervisory lamp associated with the peg in the wanted subscriber's jack glows from the time that the peg is inserted until the subscriber responds, when it darkens, in which condition it remains until the subscriber restores the receiver to the hook and causes the lamp to light up again. .The other supervisory lamp on the cord circuit is controlled in a similar manner by the subscriber who originated the call, and as that subscriber's telephone is off the hook when the peg is inserted, the lamp is not lighted at all until the subscriber replaces the receiver.^ All in all, I’m looking for opinions from users who use their cell provider for things similar to my uses.

^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Once at the receiver the equipment identifies the call, separates its pieces from the spreading code and other calls, and returns the signal back to its original 9600 bit rate.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

When both lamps glow, the operator, who thereby knows that both subscribers have restored their instruments, discontinues the connexion.
A cord circuit, similar in many respects, including the method .y.^9 Jr '' of operation, but equipped with condensers and impedance coils, in place of the repeating coil, is shown in fig. 13.
In fig. 11 a meter or counter is shown associated with the subscriber's line, and in both figs. 12 and 13 position meters are shown connected to the cord circuits. The operation of these meters is controlled by the operators. The subscriber's meter is joined in multiple with the cut-off relay, and whenever a peg is connected to the circuit a current flows through the meter. This current is small, however, and the meter is not operated until a much larger current is passed through it. .Calls are registered by pressing a key, which connects a battery through a position meter of very low resistance to the socket of the line jack, thereby furnishing the necessary energy to the meter.^ Kit inlcudes 9V batteries and snaps to connect to the battery connector inthe Kick Meter .
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.The position meter just mentioned is common to all the cords on one position and records all completed calls handled at the position.^ When used for line sharing, put a fax on one port and all incoming calls will go to the fax, while the fax will use the next available line for outgoing calls.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.Some administrations, in addition to employing the ordinary position meter, use a second one for registering ineffective calls.^ Qualcomm's CDMA system uses some very advanced speech compression techniques, utilizing a variable rate vocoder, a speech synthesiser and voice processor in one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The TDMA based IS-136 uses puts three calls into the same 30kz channel space that AMPS uses to carry one call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ When there were multiple positions that weren't covered by operators (like at night), an operator could use a plug from her switchboard in a jack of one on either side.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

In large towns served by a number of exchanges the junction equipment is an important feature. In many cases from 60 to 80 per cent. of the calls originated at an exchange are for subscribers connected to other exchanges, and in these cases the junction plant forms a considerable fraction of the whole equipment. Moreover each call junctioned is dealt with by at least two operators. .The junction circuits connecting two exchanges are invariably divided into two groups, one for traffic from exchange A to exchange B, the other for traffic from B to A. At the outgoing end the circuits are multipled on the subscribers' switchboard, while at the incoming end they terminate in plugs on a special incoming junction switchboard upon which the subscribers' lines are multipled in the usual way.^ Interesting Switchboard with only two positions with cords, but a third position with jacks for subscribers on the far right (used by right set of cords).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ When businesses began installing multiple phones within their buildings, an on-site switchboard was used to connect a particular phone to an outside line.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ In the beginning, you couldn't even call someone who was a subscriber in the competing system, since the lines didn't connect anywhere.
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

.When a subscriber at exchange A asks for a connexion to a subscriber at B, the operator at A, to whom the request is made, passes the particulars over an order wire to an operator at B. The latter names a disengaged junction circuit, then " tests " the line of the wanted subscriber, and if she finds it free, finally completes the connexion and rings the subscriber.^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Surplus Army Field Phones and Wire Device to Eliminate Induced AC Voltage on the Line Early Amplifier went Inside Handset or Phone Unusual Hand Held Circuit Loss Testing Tool .
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

During the progress of these operations the A operator connects the originating subscriber to the junction circuit named by the B operator. .There is only one signal on the cord circuit at B, and that signal is controlled by exchange A. Each of the subscribers controls a signal at A, and when either or both of the telephones are replaced, the action is indicated by the lamps there.^ Interesting Switchboard with only two positions with cords, but a third position with jacks for subscribers on the far right (used by right set of cords).
  • Telephone History... Antique Telephone & Collector's Items 11 January 2010 10:40 UTC www.sandman.com [Source type: General]

^ Yes, there is a control frequency but the mobile can only transmit on one frequency at a time.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Searching through its list of forward control channels, it picks one with the strongest signal, the nearest cell or sector usually providing that.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Control of the call is thus vested in the operator at the originating exchange, at which point the connexion must be severed before a clearing signal can appear at B.

Party Lines

.A circuit which serves more than one subscriber is termed a " party line."^ Demultiplexing those conversations is no more difficult than adding the right circuit board to a personal computer.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It's important to remember, though, that depending on the technology used, one carrier might provide more connections than a competitor does with the same amount of spectrum.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.It was originally the practice to place the calling apparatus in series in the line circuit, but the effect of the large impedance introduced by the electromagnets of the call XXVI. 18 a bells was such that not more than two or three persons could be connected without seriously impairing the efficiency of the circuit for speech transmission.^ [Clone comments] "You could make more clear that this is due to validation and fraud issues, not to the mechanics of setting up the call, since this is pretty much the same for originations and terminations."
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ There NEVER was a place I could not call from and reach home--clear as a bell.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Apple s latest iPhone 3G will be more profitable than any other product in its line-up, which includes iPods, Macs, and iTunes.

.An improvement was effected in this respect by the introduction of the " bridging " system, in which the bells possessing high inductance are placed in parallel between the two wires of the circuit.^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ An SAT is a high pitched, inaudible tone that helps the system distinguish between callers on the same channel but in different cells.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Although the bells are constantly in circuit their high impedance prevents any appreciable interference with the telephonic currents. .In America, on farmers' circuits, ten or more stations are frequently connected to one line; but in England ten is practically the maximum.^ Base stations use one frequency of that channel and mobiles use the other.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It's important to remember, though, that depending on the technology used, one carrier might provide more connections than a competitor does with the same amount of spectrum.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ That's since the mobile unit and the base station both need circuitry to transmit on one frequency while receiving on another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

In city districts the modern practice is to restrict the number to four stations per line, and to equip the exchanges and stations for selective ringing. .In one arrangement, now in extensive use, each telephone set is fitted with a relay of high inductance which is bridged across the circuit in series with a condenser.^ Like the one the businessman is now using.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.When the relay is operated it connects a bell between one of the wires of the circuit and earth, while the bell itself is arranged to respond to current pulsations in one direction only.^ There are variations of TDMA. The only one that I am aware of in America is E-TDMA. It is or was operated in Mobile, Alabama by Bell South.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The four telephones on a circuit are so wired that the relays 9-- P ..,, connect two of the bells between each wire and fl-- 0 7-..9 *"y earth, and further that one of each pair of bells responds to positive and the other to negative o-- pulsations.^ The GSmart t600 also boasts a two-megapixel camera with macro capabilities, four-band GSM connectivity, WiFi, and Bluetooth 2.0.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

.This system of course requires that the exchange equipment shall include machines _ capable of delivering a positive pulsating current and a negative pulsating current, besides the usual alternations required for the ringing of ordinary subscribers.^ Because of the availability of the MJ system to subscribers requiring the roam feature, the MK system need not be arranged for roaming..
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In another party line system a harmonic principle is employed: the ringing machines deliver alternating currents of four frequencies, while each bell is constructed to operate at a particular frequency only.^ When a system is newly installed in an area (when large cells are serving only a few customers), frequency reuse is unnecessary.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In the same way AMPS is also an operating system, using a different access technology, FDMA, or frequency division multiple access.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In particular, cell phones or mobiles use the frequencies from 824.04 MHz to 848.97 and the base stations operate on 869.04 MHz to 893.97 MHz.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Of the four bells connected to a circuit each responds to a different frequency.
Missing image
Telephone-12.jpg

Trunk Line Working

.Trunk or long-distance working is complicated by the necessity for recording all calls.^ Let's say you're making a long distance call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Countries covered The Mobal GSM World SIM works in all of the 170 countries in the dropdown list at the top of the page, as long as your handset is compatible.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Countries covered The Mobal GSM World SIM works in all of the 170 countries in the dropdown list below, as long as your handset is compatible.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.The system of the British Post Office is worked as follows: A subscriber desiring a long-distance connexion calls up his local exchange in the ordinary way, and the operator there, being informed that a trunk connexion is desired, extends the subscriber's line to the Post Office by means of a record circuit.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Let's say you're making a long distance call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ In the same way AMPS is also an operating system, using a different access technology, FDMA, or frequency division multiple access.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

At the Post Office a record operator replies and takes particulars of the connexion, and these are entered upon a ticket. .The record operator then removes her speaking apparatus from the circuit, and the local operator, receiving a disconnect signal, severs the connexion at the local exchange.^ These digital signals are repeated several times to make sure they get received.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ When the signal is received, the codes are removed from the desired signal, separating the users and returning the call to a rate of 9600 bps."
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Meanwhile the ticket is conveyed to the position where the lines to the town wanted are terminated. .If there be a line free, or when the turn of the call is reached, particulars of the connexion wanted are passed to the distant end, and the trunk operators request the local exchanges to connect the subscribers by means of junction I F..? - a From the Post Office Electrical Engineers' Journal. FIG. 12. - Typical Cord Circuit, Western Electric Co.'s System, No.^ There NEVER was a place I could not call from and reach home--clear as a bell.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ A telegraph key tap broke the circuit momentarily, transmitting a short pulse to a distant sounder, interpreted by an operator as a dot.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Call capacity gets increased over normal TDMA. This trick had been limited before to very high density telephone trunks passing traffic between toll offices.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

i Exchanges.
2+f From the Post Office Electrical Engineers' Journal. FIG. 13. - Typical Cord Circuit, British Insulated Co.'s System.
circuits to the trunk exchanges where the necessary connexions are made between the trunk line and the junctions. .The call is controlled by the trunk operators, the junction circuits being equipped in such a manner that the subscribers' signals appear at the trunk exchanges, from which point disconnecting signals are sent automatically to the local exchanges, when the connexions between the trunk and the junction circuits are removed.^ The messages include the identities of called mobiles, local general control information, channel assignments for active mobiles and "filler" words to maintain synchronism.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Transmission, the process of transmitting, of conveying intelligence from one point to another, is a long settled, traditional way to express how signals are sent along.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The slots themselves hold individual call information within the frame, that is, the multiplexed pieces of each conversation as well as signaling and control data.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The large modern trunk exchanges are equipped with relays and lamps for signalling purposes. " Calculographs " are employed for stamping the time upon the tickets, and there is associated with each trunk circuit a device which lights a lamp as soon as the scheduled limit of the period of conversation is reached.
Missing image
Telephone-13.jpg
.Particulars of calls are now passed between trunk centres to a great extent over telegraph circuits superposed upon the trunk lines.^ Call capacity gets increased over normal TDMA. This trick had been limited before to very high density telephone trunks passing traffic between toll offices.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Registration lets the local system know that a phone is active, in a particular area, and that the mobile can now take incoming calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

This arrangement permits particulars of calls to be passed over lines while conversations are in progress.

Automatic Systems

.The idea of automatic telephony is to substitute for the operator of the manual exchange an electromechanical or other switching system, which, controlled in its movement by the action of the subscriber, will automatically select, connect and disconnect circuits as desired.^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ What was stripped out was the Roam and the Manual features, and the operator-selected-channel option.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Several schemes embodying this idea have been developed, and one of them has been put into extensive operation.^ Voice traffic is digitized and portions of many calls are put into a single bit stream, one sample at a time.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Since calls are separated by time TDMA can put several calls on one channel.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The TDMA based IS-136 uses puts three calls into the same 30kz channel space that AMPS uses to carry one call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Each subscriber's circuit on this system terminates upon the incoming portion of a selector switch, called a first selector, and is multipled upon the outgoing portions of a number of similar switches called connector switches.^ A five digit code called the home system identification number (SID or sometimes SIDH) identifies the cellular carrier your phone is registered with.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Only calls originated by a subscriber pass through the selector switch (first selector) provided for his sole use; the calls incoming to him pass through one or other of the various connector switches upon which his circuit is multipled.^ In addition to channel assignment, other MTSO functions include maintaining a list of busy (that is, off-hook) mobile units and paging mobile units for which incoming calls are intended.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ I do make calls on my phone, but not as much as I use data service so call quality really isn’t that big of an issue as long as I’m able to hear the other side and they can hear me.

^ Once at the receiver the equipment identifies the call, separates its pieces from the spreading code and other calls, and returns the signal back to its original 9600 bit rate.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Each connexion involves the use of three switches, viz., a first selector, a connector switch, and a second selector which is brought into operation between the other two.^ And iDEN is, well, iDEN, a proprietary operating system built by Motorola (external link) that, among others, NEXTEL uses.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The TDMA based IS-136 uses puts three calls into the same 30kz channel space that AMPS uses to carry one call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The mobile switch assigns which of those channels to use for a given call, but has no ability to assign other channels.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The subscribers' lines in an exchange are arranged in groups of moo, which are divided in turn into sub-groups of 100 each. .By means of his first selector the circuit of a calling subscriber is connected to the outgoing end of a junction whose other end terminates upon the incoming portion of a second selector in the thousand group to which the wanted subscriber belongs.^ All incoming and outgoing calls are then routed over this channel.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A call gets going, in other words, on the control channel first and then drops out of the picture once the call gets assigned a voice channel.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ As the Cellular Development group puts it, "A CDMA call starts with a standard rate of 9600 bits per second (9.6 kilobits per second).
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The second selector in turn extends the connexion by means of another j unction circuit to one of the connector switches in the hundred group wanted, while finally the connector) switch completes the connexion.^ Before we turn to another multiplexing scheme, CDMA, let's consider how a digital cellular phone determines how to choose a digital channel and not an analog one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.One hundred circuits are connected to the outgoing portion of each switch, and the contacts upon which they terminate are arranged in a number of horizontal rows upon the face of a curved surface, at whose axis a vertical shaft is placed.^ At the same time, the number of customers in a large city can be increased from a maximum of about one thousand for a conventional system to several hundred thousand.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Not only in the number of countries it works in, but also the number of carriers it connects to in each country — in fact, you’ll get better coverage than many of the locals get, as they will be stuck using just one carrier.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.This shaft, which carries a set of " wipers " connected to the incoming circuit, is susceptible of a vertical and a rotational movement, so that the wipers may be brought, first opposite any particular horizontal series of contacts, and then into actual contact with any particular set in the series.^ A call gets set up on a control channel and another channel actually carries the conversation.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The movements of the shaft are controlled by relays and electro-magnets which operate in response to the action of the subscriber whose telephone is fitted with a 'calling mechanism which, when the subscriber calls, earths the line a certain number of times for each figure in the number of the wanted subscriber.^ Punch out the number that you want to call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Once everyone was in the store with their bag checked, I called our conductor Agent Kula back in Union Square and told him it was time for the first movement.
  • Cell Phone Symphony « Improv Everywhere 31 January 2010 13:24 UTC improveverywhere.com [Source type: General]

^ New gadgets can be complicated at the best of times, especially when you have to overcome the complexities of overseas dialing codes and unfamiliar telephone number formats.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

Wire Plant

In suburban and rural districts subscribers are usually served by means of bare wires erected upon wooden or iron poles. .As subscribers' lines are invariably short, the smallest gauge of wire possessing the mechanical strength necessary to withstand the stresses to which it may be subjected can be employed, and bronze wire weighing 40 lb per mile is commonly used.^ You may drive fifty miles, use 8 different cells and never once realize that your call has been transferred.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

In large towns telephone distribution by means of open wires is practically impossible, and the employment of cables either laid in the ground or suspended from poles or other overhead supports is necessary.
In the types of cable that were first used, the wires, usually with a cotton insulation, were drawn into lead tubes, and the tubes filled with paraffin or other similar compound, which kept the wires from the injurious effects of any moisture which might penetrate the lead tube. This form of cable has been superseded by a type with paper insulation. The separate wires are surrounded only with a loose covering of specially prepared paper, which furnishes abundant insulation. In the manufacture of the cable the wires are first enclosed in the paper, which is applied sometimes longitudinally and sometimes spirally. The conductors are then twisted in pairs with definite lays. .These pairs are laid up symmetrically into cables, each layer being protected with an additional covering of paper and all adjacent layers revolving with an opposite twist.^ Note that this list is not meant to be all-inclusive; many of the manufacturers represented here offer additional models covering a spectrum of features and specs.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ Look up all of these terms in a good telecom dictionary and see what those writers state.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The cable is then placed in an oven, and, after all moisture has been driven off, it is passed through a lead press whence it emerges protected by a continuous lead pipe. The electrostatic capacity of a cable of this type is low, and its dimensions are small, the external diameter of a cable containing 1600 ten-lb conductors being only 24 in. The conductors used for subscribers' circuits are of copper weighing from 10 to 20 lb per mile. Junction circuits are usually made up of 20 or 40 lb conductors.
.When a number of cables follow the same route, they are generally laid in conduits made up of earthenware or cement ducts; iron pipes are used when the number of cables is small.^ We use the terms 'cell' (the coverage area) and 'cell site' (the base station location) interchangeably, but they are not the same thing.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Start-up and small-city systems use a somewhat more conventional configuration with a single cell site at the center of each cell.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Make and receive calls from over 150 countries on the same number using standard direct dialing… .
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

Manholes are placed at intervals in the line of ducts to facilitate the drawing in and jointing of the cables, and surface boxes are placed in the footways for distributing purposes. Various methods of making the connexions between the large main cables and the subscribers are in use. .In one system the main cables terminate in large airtight iron boxes placed in the manholes.^ At the same time, the number of customers in a large city can be increased from a maximum of about one thousand for a conventional system to several hundred thousand.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

There, the large cables divide into a number of small cables, which are carried along the footways in pipes and are tapped at suitable points to serve subscribers. .Another method of distribution, largely adopted, is to run the lead cables into the interior of blocks of buildings, and to terminate them there in iron boxes from which the circuits are distributed to the surrounding buildings by means of rubber-covered wires run along the walls.^ Increasing capacity means putting more calls into the same amount of spectrum which means calls may be blocked and voice quality will decrease.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Aerial distribution from distributing poles is a method frequently adopted. In this case the cables terminate upon the poles, the connexions between the cable wires and the open wires being made with rubber-covered leads.
.The introduction in 1883 of the hard-drawn copper wire of high conductivity invented in 1877 by T. B. Doolittle was of the greatest importance in rendering the use of long lines practicable, and it is universally employed for such service.^ PM The long-awaited move to the use of mobile phones from different service...

Wire weighing between 150 and 400 lb per mile is generally used. The New York-Chicago line, built in 1892, is of wire 165 millimetres in diameter (No. 8 Birmingham), weighing 435 lb per mile and having a resistance of 2.05 ohms per mile. Speech has been habitually transmitted for business purposes over a distance of 1542.3 m., viz., over the lines of the American Telegraph and Telephone Company from Omaha to Boston. Conversation has been carried on over 2200 m. of No. 8 line.
As no practical process of telephone relaying has been devised, it is extremely important that the character of the line should be such as to favour the preservation of the strength and form of the telephone current. In circuits possessing high resistance and capacity and low inductance per mile, telephonic currents are rapidly attenuated, and the higher the frequency the more rapid is the attenuation. Moreover, as the velocity of propagation is a function of the frequency, there is distortion of the complex waves. .Oliver Heaviside showed mathematically that uniformly-distributed inductance in a telephone line would diminish both attenuation and distortion, and that if the inductance were great enough and the insulation resistance not too high the circuit would be distortionless, while currents of all frequencies would be equally attenuated.^ Cellular radio is like that, different ways to communicate but all having in common a distributed network of cell sites, the principle of frequency-reuse, handoffs, and so on.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Following up this idea, Professor M. I. Pupin showed that by placing inductance coils in circuit, at distances apart of less than half the length of the shortest component wave to be transmitted, a non-uniform conductor could be made approximately equal to a uniform conductor.^ At slightly less than a half inch, the Q is 50 percent thinner than its top competitors, according to Mot.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ The data rate is 48.6 Kbits/s, less than a 56K modem, with each slot transmitting 324 bits in 6.67 ms. How is this rate determined?
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Many circuits have been " loaded " in the manner proposed by Pupin during recent years, especially in underground cables, and it has been found in practice that the transmission value of these when loaded is approximately from three to four times their value unloaded. Open aerial longdistance lines have also been loaded, but not to the same extent. The introduction of inductance coils into such circuits renders them more susceptible to trouble from atmospheric electricity and more sensitive to leakage variations.
.In consequence of their high capacity, the attenuation constant of submarine cables is high, and only a small number of cables, of comparatively short length, are in use for telephonic purposes.^ Other than the fact that it is used for identification and sales purposes, what else would one use the serial number from an i-phone?

^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Its purpose is to expand a system's carrying capacity while still using the same numbers of frequencies.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Attempts have been made to improve submarine cables in this respect, and in 1906 a short cable " loaded " with Pupin coils was laid across Lake Constance. .The problem, however, of constructing a deep-sea cable satisfactorily, with suitable inductance coils inserted at short distances apart, is a difficult one, and one which it cannot be said has been solved.^ If you have two sectors facing the same way, even if they are some distance apart, you'll have the problems Mark just discussed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

(H. R. K.) Commercial Aspects. - The records of the telephone industry in Great Britain during the thirty years from 1877 to 1907 form an instructive chapter in the industrial history of the country. .The aspects which stand out most prominently in this history are: (a) The vacillation of successive governments due to the conflicting policies adopted from time to time to protect the telegraph revenues of the Post Office and to avoid the suppression of an enterprise which was becoming a public necessity and yielding substantial royalties to the PostmasterGeneral.^ Use of this site is governed by our Terms of Use and Privacy Policy Copyright ©1996-2010 Ziff Davis Enterprise Holdings Inc.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

(b) The obstructive use made by the local authorities of their power to veto underground wayleaves. (c) The remarkable success achieved by the National Telephone Company, despite these obstacles, in developing an extensive organization and a profitable business.
The chief events in chronological order are: 1876. Graham Bell's telephone patent was granted for the United Kingdom.
1877. Edison's telephone patent was granted for the United Kingdom.
1878. Professor D. E. Hughes invented the microphone, but did not apply for letters patent. The Telephone Company, Limited, was formed to acquire Bell's patent. .During the passage of the Telegraph Bill 1878 through parliament the Postmaster-General endeavoured, without success, to insert a clause declaring that the term " telegraph " included " any apparatus for transmitting messages or other communications with the aid of electricity, magnetism, or any other like agency.^ The first point is that cell phones and base stations transmit or communicate with each other on dedicated paired frequencies called channels.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

>> 1879. The Edison Telephone Company of London was formed. Both the Bell and the Edison Companies opened negotiations with the Post Office for the sale of their patents to the government, but without success. The Edison Company announced its intention to start telephone business in London, and the Postmaster-General instituted proceedings against the company for infringement of his monopoly rights under the Telegraph Act 1869.
1880. The two companies amalgamated as the United Telephone Company Ltd. Mr Justice Stephen decided (Attorney-General v. .Edison Telephone Company, 6 Q.B.D., 244) that the telephone was a telegraph, and that telephone exchange business could not legally be carried on except by the PostmasterGeneral or with his consent.^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The local telephone companies were called the wireline carriers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The decision covered also future invention in regard to " every organized system of communication by means of wires according to any preconcerted system of signals."^ Time division systems are now being regarded as legacy technologies, older methods that must be accommodated in the future, but ones which are not the future itself.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

1881. The company's appeal against the decision was withdrawn, the Postmaster-General agreeing to grant licences for restricted areas of about 5 m. in London and about 2 m. in the provinces. The licences merely condoned the infringement of the Telegraph Act 1869, and did not confer powers to erect poles and wires on, or to place wires under, any highway or private property. .The licensee was precluded from opening public call offices and from laying trunk lines from one town to another.^ In time division multiple access we separate calls by time, one after another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ We'll see with IS-136 that three calls are placed on a single radio channel, one after another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The licences were for 31 years, expiring in 1922, without any provision for purchase or compensation, and were subject to the payment of a minimum royalty to the Post Office of 10 per cent.^ There are no other hidden fees or taxes or surcharges for each call or each day, just a simple flat rate of 10 cent per minute.
  • Cellular Phone Directory of Nebraska 11 September 2009 20:57 UTC nebraska.uscity.net [Source type: General]

^ You only pay 10 cent per minute for every call, local, long distance and roaming.
  • Cellular Phone Directory of Nebraska 11 September 2009 20:57 UTC nebraska.uscity.net [Source type: General]

of the gross revenues. .The United Telephone Company confined its operations to London; subsidiary companies were formed to operate in the provinces.^ To prevent any possible cross-subsidization or favoritism, the Bell operating companies must offer their cellular service through separate subsidiaries.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The Post Office at the same time established several telephone exchanges in provincial towns so as to enable the PostmasterGeneral " to negotiate with the telephone companies in a satisfactory manner for licences."^ At the same time, the number of customers in a large city can be increased from a maximum of about one thousand for a conventional system to several hundred thousand.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It's so you can talk and listen at the same time, just like on a regular telephone.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

1882. The Postmaster-General (Mr Fawcett) declared that he would issue no more licences unless the licensees agreed to sell telephones to the Post Office. As a result only eight companies out of over seventy that had applied obtained or accepted licences.
1883. The Post Office proposed to engage in active competition with the telephone companies, but the Treasury at that time opposed this policy on the ground that the state should at most be ready to supplement and not to supersede private enterprise.
1884. The licences within restricted areas having proved unsuitable for the growing business, public opinion appealed to the Post Office to issue new licences applicable to the whole country. .All limitations of areas were removed and licensees were allowed to open public call offices but not to receive or deliver written messages, and they were allowed to erect trunk wires.^ Call capacity gets increased over normal TDMA. This trick had been limited before to very high density telephone trunks passing traffic between toll offices.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The royalty of 10 per cent.^ There are no other hidden fees or taxes or surcharges for each call or each day, just a simple flat rate of 10 cent per minute.
  • Cellular Phone Directory of Nebraska 11 September 2009 20:57 UTC nebraska.uscity.net [Source type: General]

^ You only pay 10 cent per minute for every call, local, long distance and roaming.
  • Cellular Phone Directory of Nebraska 11 September 2009 20:57 UTC nebraska.uscity.net [Source type: General]

was continued. .The Post Office reserved the right to compete either directly or by granting other licences, and it was under no obligation to grant wayleaves.^ My phone worked great no matter where I called from…the plane right after landing, my hotel rooms, or anywhere in either city.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.The new licences were to terminate in 1911 without any provision for purchase or compensation in that year, but with the option to the government to purchase the plant of the licensees in 1890, 1897, or 1904 at a price to be determined by arbitration.^ Nokia Siemens Networks sign MOU with Tamil Nadu government to set up new plant .

^ The only costs associated with the Mobal® World Phone are the purchase price, your delivery option and then the calls you make when traveling.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Access to work (BES) and personal (BIS) email Mobile Email Blackberry Data is Required With The Purchase of This Device Check if AT&T Coverage is right for you Price w/New 2 Year Contract.
  • Cell Phones from wireless carriers AT&T, BlackBerry, Sprint, T-Mobile, Verizon Wireless 28 January 2010 1:30 UTC www.letstalk.com [Source type: General]

The United Telephone Company asked parliament for rights of way in streets but was refused, and its only right to place overhead wires was obtained by private wayleaves.
1885. The United Telephone Company again applied unsuccessfully for right to lay wires underground.
1888. The application of the company for permission to lay wires in streets was again refused.
.1889. After the withdrawal of the restriction against the companies erecting trunk wires it became evident that the development of the telephone services throughout the country would be facilitated by complete intercommunication and uniformity of systems, and that economies could be effected by concentration of management.^ Even though Ethiopia was listed as a country with coverage, I just could not believe that it would actually work there.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ More recent systems (the MJ system at 150 KHz and the MK system at 450 KHz) [ Improved Mobile Telephone Service or IMTS, ed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The various companies therefore amalgamated as the National Telephone Company.
1890. The government had the option to buy out the: companies under the licences of 1884, but did not exercise it. The Bell telephone patents expired. The National Telephone Company applied to the London County Council for permission to lay wires underground and continued efforts till 1899 to obtain this power, but without success.
.1891. The duke of Marlborough, in the name of the New Telephone Company, inaugurated a campaign for cheaper telephone services, but the New Telephone Company was subsequently merged in the National Telephone Company.^ In the international cell phone industry many new companies and services appear and disappear, leaving their customers searching for a replacement.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.1892. The National Telephone Company again applied to parliament for powers to lay wires underground; public discontent with inadequate telephone services was expressed, and at the same time the competition of the telephone with the Post Office telegraph became more manifest.^ But at the same time, Smart phone speed will be… read more… .

^ CDMA features soft handoffs, where two or more cell sites may be handling the call at the same time.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ More recent systems (the MJ system at 150 KHz and the MK system at 450 KHz) [ Improved Mobile Telephone Service or IMTS, ed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The government again changed its policy. .It compelled the companies to sell their trunk wires to the Post Office, leaving the local exchanges in the hands of the companies.^ How does a Real Estate company sell its office without causing confusion?

^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

It also expressed willingness that the companies should have rights of way in the streets.
1893. The National Telephone Company again applied to parliament for power to lay wires underground, but was refused. .1894. The draft agreement between the government and the National Telephone Company to carry out the policy of 1892 was submitted to parliament and led to much discussion.^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The local telephone companies were called the wireline carriers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Local authorities (particularly London and Glasgow) refused to permit the company to lay wires underground.^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

1895. A select committee of the House of Commons (with Mr Arnold Morley, Postmaster-General, as chairman) was appointed " to consider and report whether the provision now made for the telephone service in local areas is adequate, and whether it is expedient to supplement or improve this provision either by the granting of licences to local authorities or otherwise." The committee was not unanimous and made no report, but merely submitted to the House the evidence it had taken.
.1896. The trunk wires were transferred to the Post Office in pursuance of the policy of 1892, but for all practical purposes the local authorities had vetoed the permission of the government to the company to lay wires underground.^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

1897. The government had an option to purchase the plant of the company under the licences of 1884, but did not exercise it. .The corporation of Glasgow having persisted in its efforts to obtain a licence, the Treasury appointed Sheriff Andrew Jameson (afterwards Lord Ardwall) a special commissioner to hold a local inquiry in Glasgow to report whether the telephone service in that city was adequate and efficient and whether it was expedient to grant the corporation a licence.^ The efficient use of frequencies that results from the cellular approach permits Advanced Mobile Phone Service customers to enjoy a level of service almost unknown with present mobile telephone service.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The commissioner reported that the service was adequate but not efficient; that the rates were reasonable but that the corporation was responsible for unreasonably withholding facilities, thus rendering the service inefficient; that it was inexpedient to grant the corporation a licence because the funds of a city ought not to be applied for the benefit of a limited class of citizens; that delay and waste would result from two systems in one area and would increase the difficulties of the government in 1911; and that the corporation had not proved it could work the licence without placing a burden on the rates.^ Even though Ethiopia was listed as a country with coverage, I just could not believe that it would actually work there.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Moving from one service area to another causes registration to begin again.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

1898. The policy of the government was again changed; Mr R. W. Hanbury, Financial Secretary to the Treasury and representative in the House of Commons of the PostmasterGeneral, advocated the granting of licences to local authorities. A select committee was appointed with Mr Hanbury as chairman to consider " whether the telephone service is calculated to become of such general benefit as to justify its being undertaken by municipal and other local authorities, and if so under what conditions." The committee reported (9th August) that the telephone service was not likely to become of general benefit " so long as the present practical monopoly in the hands of a private company shall continue." .The committee considered that the Post Office was not prevented either by legal agreement or by good faith from limiting or ending the monopoly of the company, and that competition appeared to be both expedient and necessary in order to extend and popularize the service and to avoid the danger that a purchase of the company's undertaking at an inflated price might be forced upon the government.^ My contract with Verizon ends in a few months and I’ve been researching other companies as I feel I’m paying too much for Verizon’s service.

^ In the international cell phone industry many new companies and services appear and disappear, leaving their customers searching for a replacement.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.While considering that a really efficient Post Office service would afford the best means for securing such competition, it recommended that general, immediate and effective competition should at once be undertaken either by the Post Office or by local authorities.^ This means having upgrades done in order to make it the best ride you can afford.

^ In a continuing effort to provide the best wireless service for local residents in Orange County, Verizon Wireless has expanded its network with a new cell site in Cornwall.

.The Association of Municipal Corporations passed resolutions on the 28th of April that " the subject of telephonic supply should be treated as an imperial and not as a local one, and that the Postmaster General should have the sole control of the telephone system," and " that in the event of the Postmaster-General not taking over the telephone service it should be competent for municipal and other local authorities to undertake such services within areas composed of their own districts or combination of such districts."^ System Operation: Unlike the MJ and MK systems, Advanced Mobile hone Service dedicates a special subset of the 333 allocated channels solely to signaling and control.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Also, because of the stored-program control capability of MTSOs equipped with the lAESS system, Custom Calling Services and man other features can be offered, some unique to mobile service.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ More recent systems (the MJ system at 150 KHz and the MK system at 450 KHz) [ Improved Mobile Telephone Service or IMTS, ed.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.1899. In pursuance of the report of the select committee, 1898, the Telegraph Act 1899 was passed to enable the Post Office to develop its telephone exchange business, for which a loan of 2,000,000 was sanctioned, and to empower local authorities, subject to certain conditions, to enter upon telephone business.^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The licence of the National Telephone Company was extended so as to be co-extensive with that of a competitive licence for any locality on condition that the company should afford intercommunication with the telephone systems of the new licensees.^ The local telephone companies were called the wireline carriers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In short, all-round competition was authorized, and the Post Office decided to establish a telephone system in London in competition with the company.^ Originally, all mobile telephone systems operated manually, much as most private radio systems do today.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.1900. The Telegraph Act 1899, while providing for intercommunication between the telephone systems of the local authorities and the company, did not give the Post Office the right to demand intercommunication between its exchanges and those of the company.^ The local telephone companies were called the wireline carriers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The Post Office co-operated with the London County Council to put difficulties in the way of the company which had placed wires underground in London with the consent of the local road authorities.^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

In February the Postmaster-General applied for an injunction to restrain the company from opening any street or public road within the county of London without the consent of the Postmaster - General and the London County Council, which injunction was granted in July.
1901. The government policy of 1899 was abandoned in London, the Post Office making an agreement with the company in regard to the London business. The company consented to free intercommunication between its subscribers and those of the Post Office, and undertook to charge rates identical with those charged by the Post Office. The Postmaster-General on the other hand agreed to provide underground wires for the company on a rental, and agreed to buy in 1911 the company's plant in London at the cost of construction less allowance for repairs and depreciation.
1904. The government had option to purchase the company's provincial plant under the licence of 1884. Negotiations took place, but no agreement was reached.
1905. The government contracted to buy the company's plant in 1911, thus in effect annulling the act of 1899 which had failed to accomplish its object of establishing all-round competition.
.By 1907 altogether 59 local authorities had examined the proposition of establishing telephone systems after 1899, and licences were granted to local authorities at Brighton, Belfast, Chard, Glasgow, Grantham, Huddersfield, Hull, Portsmouth, Swansea, Tunbridge Wells, Oldham, Scarborough and Hartle - pool, but only six municipalities proceeded with the business.^ The Bell System originally planned for 1000 channels but was given only 666 by the FCC. When cellular proved popular the FCC was again approached for more channels but granted only an extra 166.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.Glasgow opened its exchange in March 1901, Tunbridge Wells in May 1901, Portsmouth in March 1903, Brighton in October 1903, Swansea in November 1903 and Hull in October 1904. The Tunbridge Wells and Swansea municipal undertakings were subsequently sold to the National Telephone Company, and the Glasgow and Brighton undertakings to the Post Office.^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Hull and Portsmouth were the only municipal telephone systems working in 1907.
.The effect of the unsettled policy of the Post Office until 1905 and of the difficulties created by the local authorities was that the National Telephone Company was never able to do its best to develop the enterprise on the most efficient lines.^ The local telephone companies were called the wireline carriers.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In 1885 there were only 3800 telephone subscribers in London and less than io,000 in the rest of the United Kingdom, and telephonic services were available in only about 75 towns, while in the same year the American Bell Telephone Company had over 134,000 subscribers.^ Because of these effects, radio channels can be used reliably to communicate at distances of only about 20 miles, and the same channel (frequency) cannot be reused for another talking path less than 75 miles away except by careful planning and design.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The Mobal World Phone offer is only available to North American residents.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.The removal in 1884 of the prohibition against the erection of trunk lines at once enabled considerable expansion to take place.^ A built-in SD/MMC expansion slot enables file storage on removable Flash media.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

Within six years the services had been extended to 400 towns with about 55,000 subscribers. Large as this progress was it would have been much greater if the Telephone Company had been granted adequate powers to put wires underground and thus instal a complete metallic circuit in place of the single wire, earthreturn, circuit which it was constrained to employ. Subsequently the progress was still greater. .In 1906 there were 30,551, equal to 7.2 per cent., more telephone stations in the United Kingdom than in the ten European countries of Austria, Hungary, Belgium, Denmark, Holland, Italy; Norway, Portugal, Russia, Sweden and Switzerland, having a combined population of 288 millions as against a population of 42 millions in the United Kingdom.^ God, Country, and Notre Dame is more than an inscription above an entrance to the Sacred Heart Church on the campus of Notre Dame and more than the title of Father Ted Hesburgh s autobiography.

.Apart from France, Germany and Switzerland, there was no European country that had as many telephones working as London.^ Even though Ethiopia was listed as a country with coverage, I just could not believe that it would actually work there.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Mobal’s GSM World Phone works in over 150 countries with no minimums, fees or service charges.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

^ Unlike many other phones, the Mobal GSM World Phone works well in over 150 countries, and you never need to change the SIM card.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

.That city, with a population of 6 millions, had nearly as many telephones as the whole of Sweden with about the same population, or as the whole of France, with a population of 39 millions.^ At the same time, the number of customers in a large city can be increased from a maximum of about one thousand for a conventional system to several hundred thousand.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The only European country which can be compared with the United Kingdom in telephone development is Germany. With a population of 58 millions there are 10.2 telephones per loon of the population in that country compared with 10 15 in Great Britain and Ireland. .The development of telephony in the United States of America is much greater than anywhere else; on the 1st of January 1907, 5 per cent.^ It doesn't get much more authoritative than the guys who developed the stuff!"
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

of the population were telephone subscribers.

Tariffs

.Telephone business is characterized by two features: (I) that the capital account is never closed, and (2) that the costli - ness of the service increases with the size of the undertaking.^ This pair of Windows Mobile PDA/phones come with a range of services that target the needs of small and medium-sized businesses (SMBs).
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ Two of the VoIP phone services that are used frequently by businesses are Jajah and Lingo.

^ May require a one or two year service term agreement with featured wireless carrier.
  • Cell Phones from wireless carriers AT&T, BlackBerry, Sprint, T-Mobile, Verizon Wireless 28 January 2010 1:30 UTC www.letstalk.com [Source type: General]

The original method of charging adopted in Great Britain took the telephone instrument as the unit, charging a fixed annual rental independent of the amount of use to which the instrument was put. .The study of telephone economics showed that the proper basis for charging was the " message-mile," on the theory that the user should pay according to the facilities offered and the extent to which he made use of them.^ HTC's Touch Dual uses the TouchFLO user interface that made its debut with the HTC Touch , but also includes a slide-out QWERTY keyboard.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ The HTC-manufactured HT1100 uses the TouchFLO user interface that made its debut with the HTC Touch , but also includes a slide-out QWERTY keyboard.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

^ Gigabyte Communications offers a smartphone wrapping Windows Mobile 6.5 in a custom "SmartZone" user interface built using Adobe's Flash technology.
  • The Windows Mobile Phones Showcase - Windows For Devices Articles - Windows for Devices 28 January 2010 1:30 UTC www.windowsfordevices.com [Source type: General]

.In a large city, where several inter - connected exchanges have to be built and thousands of subscribers are put into communication with each other, the service is at once more costly and more valuable than in a small town with a few hundred subscribers accommodated in one exchange.^ Membership has actually grown to more than one hundred th...

^ Later, as the service grows, a dense system will have many small cells and many customers), a given channel in a large city could be serving customers in twenty or more nonadjacent cells simultaneously.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Apple s latest iPhone 3G will be more profitable than any other product in its line-up, which includes iPods, Macs, and iTunes.

.Differences not only in the size of towns, but in the arrangement and char - acter of the population, make each district a telephone problem b3, itself, and nullify close comparisons between telephone rates and telephone efficiencies in different areas and different countries.^ In any given area, both the size of the cells and the distance between cells using the same group of channels determine the efficiency with which frequencies can be reused.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Most cells have been split into sectors or individual areas to make them more efficient and to let them to carry more calls.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

But the tendency is towards a system of charging a moderate sum to cover the rent of the instrument and an additional fee per message. For instance, in the county of London, the telephone tariff is £5 per annum plus id. per call within the county and 2d. per call outside the county. Subscribers outside the county of London pay only £4 in annual subscription and id. per call to sub - scribers on the same exchange and 2d. per call to subscribers on other exchanges. In each case the minimum annual amount for message fees is £1,. los. The alternative is given of an unlimited service (" flat rate ") at £17 per annum. In the provinces the unlimited service costs only £7, tos. for subscribers within half a mile of the exchange, £1, 5s. being charged for every additional quarter of a mile or fraction thereof. The toll or message rates are £3, with id. per call, with a minimum of £1, Ios. .As the cost of the service varies in proportion to the amount of use, the toll rate is more scientific, and it has the further advantage of discouraging the unnecessary use of the instrument, which causes congestion of traffic at busy hours and also results in lines being " engaged " when serious business calls are made.^ A frequency might be 1.25 or even 5 MHz wide, 10 times or more the width a conventional call might use.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Inmates are being overcharged when they phone home - prisoners are charged seven times the rate from a standard call box for a half-hour call to loved ones.

^ Qualcomm's CDMA system uses some very advanced speech compression techniques, utilizing a variable rate vocoder, a speech synthesiser and voice processor in one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The tariff for unlimited use has to be made very high to cover the cost of the additional burdens thrown upon the service, and it only works economically to the individual subscriber who has an exceptionally large number of calls originating from his instrument. The message-rate system equalizes the charges according to the service rendered. .Another method of charge, known as the " measured service rate," is de - signed to make the subscriber pay in proportion to the quality and quantity of the service he takes.^ Maintenance of this ratio ensures that a majority of users will rate the service quality good or better.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.It is widely used in America, and was introduced into Great Britain in 1907. The subscriber pays a fixed annual rent which covers a certain number of free out - ward calls, say boo; additional calls he purchases in advance in blocks of several hundred at so much per hundred, the price being reduced as the number increases.^ Punch out the number that you want to call.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ A frequency might be 1.25 or even 5 MHz wide, 10 times or more the width a conventional call might use.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Instead of concentrating a message in the smallest spectrum possible, say in a radio frequency 10 kHz wide, CDMA spreads that signal out, making it wider.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.For subscribers who desire the telephone for occasional use, the party-line system has been devised, whereby several telephones are connected to one line leading to the exchange.^ (Time division duplexing, as used in cordless telephone schemes: DECT and Personal Handy Phone systems might have a place but this still isn't clear.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Qualcomm's CDMA system uses some very advanced speech compression techniques, utilizing a variable rate vocoder, a speech synthesiser and voice processor in one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.In London a two - line party service costs £3 per annum, the message fees being id.^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

per call to subscribers within the county and 2d. per call to those outside it, with a minimum of £3. .The fee charged for the use of public telephone call offices is 2d.^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

per message.
The trunk line service is charged for on rates which vary from 3d. (for 25 m.) up to is. (for 100 m.) for a three minutes' conversa - tion between 6 a.m. and 8 p.m. For every 40 m. above Too m. an additional 6d. per conversation is charged. .A reduction has been made in the charges for trunk calls at night, and calls for single periods of three minutes are allowed at half the ordinary rates between 7 p.m.^ Inmates are being overcharged when they phone home - prisoners are charged seven times the rate from a standard call box for a half-hour call to loved ones.

and 7 a.m. A call between London and Liverpool, which ordinarily costs 2s., can be made for is. between those hours. The growth of traffic on this basis has been considerable, and the arrangement has proved of advantage to the public, as it provide, cheap facilities at times which are convenient for social conversation.
.Telephone subscribers may telephone ordinary messages to any post office which may be reached through the local exchange system, or by means of the trunk wires, in order that the messages may be written down and forwarded as telegrams or express letters or ordinary letters.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Subscribers to exchanges may also make arrangements to have all telegrams (except Press telegrams) ad - dressed to them delivered by telephone instead of messenger. Telephone subscribers may also obtain the services of an express messenger by telephoning to the nearest post office connected with the exchange.
15,000 6% 1st preference shares of £10 each.
. £150,000
15,000 6% 2nd preference shares of Do each
. 150,000
250,000 5% 3rd preference shares of £5 each .
. 1,250,000
6% preferred stock. ... .
. 2,225,000
Deferred stock. .. .. .
. 3,366,425
71,715 new shares of £5 each.. .
. 358,575
£ 7,500,000
31% debenture stock .
. 2,000,000
4% debenture stock .
. 1,716,593
fI I,216, 593
National Telephone Company. - The issued share and debenture capital of the company on the 31st of December 1907 was: - The company has a reserve fund of £2,467,707, the major part of which is invested in the business. The gross income for the year 1907 amounted to £2,702,228, of which £257,920 was paid to the Post Office in respect of royalties. The working expenses amounted to £1,530,093 or 62.6 per cent. of the net income, leaving a profit for the year of £914,216.
.At the time of the formation of the various telephone companies the enterprises were regarded as speculative, and much of the capital was raised at a discount.^ New gadgets can be complicated at the best of times, especially when you have to overcome the complexities of overseas dialing codes and unfamiliar telephone number formats.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

The business subsequently proved profitable, good dividends were paid, and the securities for the most part commanded a premium in the market. .After the consolidation of the companies in1889-1890the profits declined, patent rights had expired, material reductions were made in the rates for telephone services, and considerable replacements of plant became necessary, the cost of which was charged to revenue.^ AT&T, which made $3.46 billion in profits during the first quarter, hopes to increase prices for wireline phone services in Tennessee starting July 26.

^ In the international cell phone industry many new companies and services appear and disappear, leaving their customers searching for a replacement.
  • International Cell Phone and World Phones for Travel 31 January 2010 13:24 UTC www.mobal.com [Source type: General]

Agreement of 1905

.By this agreement the Postmaster-General agreed to purchase all plant, land and buildings of the National Telephone Company in use at the date of the agreement or constructed after that date in accordance with the specification and rules contained in the agreement, subject to the right of the Postmaster-General to object to take over any plant not suited to his requirements.^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ The first law prohibits all drivers from using a handheld wireless telephone while operating a motor vehicle.

^ Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The price is to be fixed by the Railway and Canal Commissioners as arbitrators on the basis of the " then value," exclusive of any allowance for past or future profits or any compensation for compulsory sale or other consideration. In those cases in which the company's licence has been extended beyond 1911 (Glasgow to 1913, Swansea to 1926, Brighton to 1926 and Portsmouth to 1926) the Postmaster-General will buy the unexpired licence with allowance for goodwill. .The Postmaster-General agreed also to buy the private wire plant of the company at a value based upon three years' purchase of the net profits on the average of the three years ending 31st of December 1911. The Postmaster-General also agreed to lay underground wires for the company at an annual rental of L1 per mile of double wire in any local area in which the company was operating, but not in areas in which the municipalities had established exchanges.^ In many areas, the wire-line carrier will be the local operating company.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ Cell size is based on the traffic density expected in the area and can range from 1 to 10 miles in radius.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ One license went automatically to the local telephone companies, in telecom parlance, the local exchange carriers or LECs.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Free intercommunication was established by the agreement between the subscribers of the company and those of the Post Office, and a scale of charges was adopted or arranged to be agreed as binding on both the Post Office and the company. .The late Mr W. E. L. Gaine, general manager of the company, stated before the Select Committee that in the view of the directors the bargain was a hard one, because it gave no consideration in respect of the goodwill of the great business, with its gross income of over £ 2,000,000 per annum and its net revenue of over £750,000, which the company had built up.^ Before we get to them, let's stop here and review, because it is hard to think of the big picture, the overall subject of cellular radio, when we get involved in details.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ No setting up on one radio frequency channel and then moving off to another.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

The company had had to pay for all the experiments and mistakes which are inherent in the launching and development of any new industry. It had paid the Post Office in royalties already £1,848,000, and the Post Office under the agreement would step into the business in 1911 by merely paying for the plant employed. The Association of Municipal Corporations and the London County Council, on the other hand, considered the terms of purchase to be too favourable to the company. The London County Council, according to the statement of its comptroller, was disturbed by the hope expressed by the manager of the company, that the holders of the company's ordinary shares would obtain the par value of their shares in 1911. Inasmuch as the debenture stocks and preference shares would have to be redeemed in 1911 at premiums ranging from 3 to 5 per cent., the state would have to pay the company £253,000 in excess of the total of the outstanding securities in order to enable the ordinary shares to receive par, and in the council's view this payment would diminish the p robability of the Post Office being able to afford a substantial reduction in the telephone charges.

Post Office Telephones

The number of trunk wire centres open on the 31st of March 1907 was 533, and the total number of trunk circuits was 2043, containing about 73,000 m. of double wire. .The capital expenditure on the purchase and development of the trunk wire system amounted to £3,376,252. The total number of conversations which took place over the trunk wires during the year1906-1907was 19,803,300. The gross revenue derived from the trunk services was £480,658, being an average of 5.82d.^ The FCC intends cellular service to be regulated by competition, with two competing system providers in each large city: a wire-line carrier and a radio common carrier.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ During the development phase it was realized that deployment of CDMA meant turning off channels in the analog system.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

per conversation. .The total number of subscribers to the Post Office provincial exchanges on the 31st of March 1907 (excluding those in Glasgow and Brighton) was 10,010, and the number of telephones rented was 12,006. The Glasgow system included 11,103 subscribers' lines with 12,964 telephones, and the Brighton system contained 1542 subscribers lines with 1884 telephones.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ By the seventies, it included a total of thirty-three 2-way channels below 500 megahertz MHz), as shown in Table 11-2.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

.The sum received by the Post Office as rental in respect of private wires was £183,000. The years' working of the whole telephone system of the Post Office showed a balance of £451,787 after payment of the working expenses, while the estimated amount required to provide for depreciation of plant and interest at 3 per cent.^ Originally, all mobile telephone systems operated manually, much as most private radio systems do today.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

on the total expenditure of £7,252,000 was £432,726.
."The number of telephones connected with the Post Office system in the metropolitan area on the 31st of March 1907 was 41,236, and additional subscribers were being connected at the rate of about 150 a week.^ One desirable feature of a mobile telephone system is the ability to roam; that is, subscribers must be able to call and be called in cities other than their home areas.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

There were 425 post office call-offices in the London area. The length of underground pipes which had been laid in the metropolitan area for telephone purposes was 2030 m. Cables containing 317,789 m. of wire had been laid, including 69,066 m. rented by the National Telephone Company. The average cost of constructing an exchange circuit in the metropolitan area (including the installation of telephone instruments and of exchange apparatus, but excluding the provision of spare plant) has been £33. Taking into account the whole system (including spare plant of all kinds), the capital expenditure per station (i.e. per telephone connected with an exchange) stands at less than £50.

International Telephone Lines

The Anglo-French telephone service, which was opened between London and Paris in April 1891, was extended to the principal towns in England and France on the 11th of April 1904. The service has since been extended to certain other English provincial towns; and the Anglo-Belgian telephone service has similarly been extended. .There are now four circuits between London and Paris, one between London and Lille, and two between Londofi and Brussels, the last carrying an increasing amount of traffic.^ Right now all digital cellular radio systems are second generation, prioritizing on voice traffic, circuit switching , and slow data transfer speeds.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ It's important to remember, though, that depending on the technology used, one carrier might provide more connections than a competitor does with the same amount of spectrum.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

^ TDMA's chief benefit to carriers or cellular operators comes from increasing call capacity -- a channel can carry three conversations instead of just one.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

Experiments have been made in telephonic communication between London and Rome by way of Paris. .It was found possible to exchange speech when the conditions were exceptionally favourable; but in spite of the partial success of the experiment, a public service between the two capitals is not at present practicable.^ Airphone, Nextel, SMR, and public safety services use the bandwidth between the two cellular blocks.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

REFERENCES

.Reports of Select Committee on Telephone and Telegraph Wires (1885), of Select Committee on Telegraph Bill (1892), of Joint Committee of the House of Lords and the House of Commons on Electric Powers (Protective Clauses) (1893), of Select Committee on Telephone Service (1895), of Select Committee on Telephones (1898), and of Select Committee on Post Office (Telephone) Agreement (1905); Treasury Minutes (1892 and 1899); Annual Reports of the Postmaster-General; Report to the Treasury by Sheriff Andrew Jameson on Glasgow Telephone Enquiry (1897); H. R. Meyer, Public Ownership and the Telephone in Great Britain (London, 1907); E. Garcke, Manual of Electrical Undertakings (1896-1908).^ Here's some great reading on the transition from mobile telephone service to cellular.
  • Cellular Telephone Basics 16 September 2009 22:41 UTC www.privateline.com [Source type: FILTERED WITH BAYES]

(E. GA.)


Simple English

For the Lady Gaga song, see Telephone (song).

A telephone is an electric tool. Using a telephone, two people who are in different places can talk to each other. Early telephones needed to be connected with wires. Now telephone calls can be sent with radio. This is also called wireless.

Most people believe that the telephone was invented in 1876 by Alexander Graham Bell. He was a 29-year old Scotsman living in the USA. But Antonio Meucci developed and patented a working telephone in the USA in 1871. This was five years earlier than Bell. Meucci was unable to find someone to provide him with the money to finance his project. His wife was sick and had to stay in bed. Meucci invented his "teletrofono" to talk to her while he worked in his workshop.

Types of telephones

There are many different types of telephone. A telephone that can be carried around is called a mobile phone or cell phone. These became popular in the late 1980s. These days most people carry mobile phones and in some cities or countries it is unusual to not have one. Some mobile phones are able to make telephone calls using satellites instead of masts on the ground, which means people can make calls from anywhere in the world.

Computers can use a machine called a modem to talk to other computers over a telephone line. This allows a computer to connect to other computer networks including the Internet.

In most countries there are public telephones. To use one people have to pay with coins, a credit card or a prepaid card.

Most countries have a telephone network. In less developed countries cell phones are used as a cheaper and faster way to bring modern communications to the countryside.

Telephone number

Each telephone has its own number. Today, telephone numbers are about seven to ten digits long. Part of the telephone number is called the area code. Area codes are used to make sure the numbers are not the same in two different places. Each area has their own area code.krc:Телефонrue:Телефон


Citable sentences

Up to date as of December 02, 2010

Here are sentences from other pages on Mobile phone, which are similar to those in the above article.








Got something to say? Make a comment.
Your name
Your email address
Message