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28.8 kbit/s serial port modem from Motorola
.A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.^ Modems ( mo dulators/ dem odulators) are data communication devices that convert digital signals to analog signals, and vice versa.
  • Modems (Linktionary term) 12 September 2009 15:13 UTC www.linktionary.com [Source type: FILTERED WITH BAYES]

^ Modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.
  • Modem Drivers - Free Modem Drivers 12 September 2009 15:13 UTC www.downloadatoz.com [Source type: General]

^ A modem also receives modulated signals and demodulates them, recovering the digital signal for use by the data equipment.
  • modem (communications) -- Britannica Online Encyclopedia 18 January 2010 13:44 UTC www.britannica.com [Source type: Reference]

.The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data.^ Modems ( mo dulators/ dem odulators) are data communication devices that convert digital signals to analog signals, and vice versa.
  • Modems (Linktionary term) 12 September 2009 15:13 UTC www.linktionary.com [Source type: FILTERED WITH BAYES]

^ From a data communications perspective, a modem is a device that converts the digital bit stream into analog signals that are suitable for transport over standard voice circuits.
  • Data Modulation Devices (MODEMs) 12 September 2009 15:13 UTC telecom.tbi.net [Source type: Reference]

^ Modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.
  • Modem Drivers - Free Modem Drivers 12 September 2009 15:13 UTC www.downloadatoz.com [Source type: General]

.Modems can be used over any means of transmitting analog signals, from driven diodes to radio.^ However, the response time will be reduced as the number of sites increases since it takes about 200 milliseconds to poll each site using radio modems.
  • Radio Modem AN 18 January 2010 13:44 UTC www.dopsys.com [Source type: FILTERED WITH BAYES]

^ Modems ( mo dulators/ dem odulators) are data communication devices that convert digital signals to analog signals, and vice versa.
  • Modems (Linktionary term) 12 September 2009 15:13 UTC www.linktionary.com [Source type: FILTERED WITH BAYES]

^ From a data communications perspective, a modem is a device that converts the digital bit stream into analog signals that are suitable for transport over standard voice circuits.
  • Data Modulation Devices (MODEMs) 12 September 2009 15:13 UTC telecom.tbi.net [Source type: Reference]

.The most familiar example is a voiceband modem that turns the digital 1s and 0s of a personal computer into sounds that can be transmitted over the telephone lines of plain old telephone services (POTS), and once received on the other side, converts those 1s and 0s back into a form used by a USB, Ethernet, serial, or network connection.^ The receiving computer Demodulated the tones back into ones and zeros.

^ PPP Users A user dials into a modem pool using PPP to establish a network connection.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ In FIG. 1, an ADSL modem 1 is connected to a personal computer 2.
  • ADSL modem - US6778595 18 January 2010 13:44 UTC www.patents.com [Source type: Reference]

.Modems are generally classified by the amount of data they can send in a given time, normally measured in bits per second (bit/s, or bps).^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ At higher speeds, modems are measured in terms of bits per second (bps).
  • modem definition - isp.webopedia.com - The Glossary for Internet Service Providers 12 September 2009 15:13 UTC isp.webopedia.com [Source type: General]

^ The bps rate of a modem is the measure of how many bits per second the modem transmits.
  • Talking Serially: Modems 18 January 2010 13:44 UTC ibgwww.colorado.edu [Source type: Reference]

.They can also be classified by Baud, the number of times the modem changes its signal state per second.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The baud rate of a modem is the measure of how many times per second a modem's signal changes.
  • Talking Serially: Modems 18 January 2010 13:44 UTC ibgwww.colorado.edu [Source type: Reference]

^ Also, a number of different notifications about modem state changes are available.
  • ModemMaster ActiveX :: OLE component for data modem operations 18 January 2010 13:44 UTC www.softcab.com [Source type: Reference]

.For example, the ITU V.21 standard used audio frequency-shift keying, aka tones, to carry 300 bit/s using 300 baud, whereas the original ITU V.22 standard allowed 1,200 bit/s with 600 baud using phase-shift keying.^ It uses frequency shift keying to deliver up to 300 bps in each direction.
  • POTS Modem Impairment FAQ 18 January 2010 13:44 UTC www.tschmidt.com [Source type: Reference]

^ In frequency shift keying, a different tone (frequency) is used for the different bits (see How Guitars Work for a discussion of tones and frequencies).

^ On a 2400 bit line, there are 4 frequencies in use: Originate 0, originate 1, Receive 0, Receive 1.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Faster modems are used by Internet users every day, notably cable modems and ADSL modems.^ The second is to use a Cable modem.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Note that a different cable is used for each modem.
  • US Robotics External Modem V 18 January 2010 13:44 UTC www.vendapin.com [Source type: General]

^ Internet Access Controls gives parents or employers the power to decide when users can access the Internet or use Internet applications such as chat and instant messaging, online gaming or all Internet access.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

.In telecommunications, wide-band radio modems transmit repeating frames of data at very high data rates over microwave radio links.^ This modem transmits and receives data from each of the remote site radio modems.
  • Radio Modem AN 18 January 2010 13:44 UTC www.dopsys.com [Source type: FILTERED WITH BAYES]

^ Support high speed data transmit...
  • CDMA Data Card, CDMA Data Card Manufacturers & Suppliers 18 September 2009 5:38 UTC www.alibaba.com [Source type: General]

^ G Card 1 Chip: Qualcomm 5500 2 Connected rate: 99% 3 Work band: 800MHz 4 Data rate : Forward Link up to 2.4Mbps...
  • 3G Data Card, 3G Data Card Manufacturers & Suppliers 18 September 2009 5:38 UTC www.alibaba.com [Source type: Academic]

.Narrow-band radio modem is used for low data rate up to 19.2k mainly for private radio networks.^ Not actually an ITU standard - up to 19.2K data.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ However, the response time will be reduced as the number of sites increases since it takes about 200 milliseconds to poll each site using radio modems.
  • Radio Modem AN 18 January 2010 13:44 UTC www.dopsys.com [Source type: FILTERED WITH BAYES]

^ Uses 3G network resource instead of wired transmission.VOP- 3G adopts external USB 3G data card , When network situation changes,...
  • 3G Data Card, 3G Data Card Manufacturers & Suppliers 18 September 2009 5:38 UTC www.alibaba.com [Source type: Academic]

.Some microwave modems transmit more than a hundred million bits per second.^ Modem speeds are typically measured in bits per second.
  • Technology Guide: Computer Modems 12 September 2009 15:13 UTC static.tigerdirect.com [Source type: FILTERED WITH BAYES]

^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This is equivalent to 1,000 times faster than a standard 28.8 Kbps (thousand bits per second) telephone modem in a shared broadcast environment.
  • http://www.motorola.com/content.jsp?globalObjectId=7921-10345 18 January 2010 13:44 UTC www.motorola.com [Source type: General]

.Optical modems transmit data over optical fibers.^ This modem transmits and receives data from each of the remote site radio modems.
  • Radio Modem AN 18 January 2010 13:44 UTC www.dopsys.com [Source type: FILTERED WITH BAYES]

^ Online State: To transmit or receive data, the modem must be in the online state.
  • Using Basic AT Modem Commands 18 January 2010 13:44 UTC support.microsoft.com [Source type: FILTERED WITH BAYES]

^ This modem uses a modulation scheme that encodes data by using four specific "phase shifts" of the transmitted carrier.
  • Data Modulation Devices (MODEMs) 12 September 2009 15:13 UTC telecom.tbi.net [Source type: Reference]

.Most intercontinental data links now use optical modems transmitting over undersea optical fibers.^ Most modems use an AT command set.
  • Modem-HOWTO: Modem Configuration (excluding serial port) 12 September 2009 15:13 UTC tldp.org [Source type: FILTERED WITH BAYES]
  • Modem-HOWTO: Modem Configuration (excluding serial port) 18 January 2010 13:44 UTC www.tldp.org [Source type: FILTERED WITH BAYES]

^ It's all to do with the speed of the data channels (9.6 or 14.4), the number of channels they will allow you to use (4 or 6 total) and how they are split between receive and transmit (2 and 2 or 3 and 1, for example).
  • Ross Barkman's Home Page 18 January 2010 13:44 UTC www.taniwha.org.uk [Source type: FILTERED WITH BAYES]

^ Form factor Data link protocol Features RAM installed size Modem interface type See all 1274 results 1 2 3 4 ...
  • Buy Modems - Best Modem prices - Shopper.com 18 January 2010 13:44 UTC shopper.cnet.com [Source type: General]

.Optical modems routinely have data rates in excess of a billion (1x109) bits per second.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ From a data communications perspective, a modem is a device that converts the digital bit stream into analog signals that are suitable for transport over standard voice circuits.
  • Data Modulation Devices (MODEMs) 12 September 2009 15:13 UTC telecom.tbi.net [Source type: Reference]

^ This is equivalent to 1,000 times faster than a standard 28.8 Kbps (thousand bits per second) telephone modem in a shared broadcast environment.
  • http://www.motorola.com/content.jsp?globalObjectId=7921-10345 18 January 2010 13:44 UTC www.motorola.com [Source type: General]

.One kilobit per second (kbit/s, kb/s, or kbps) as used in this article means 1,000 bits per second and not 1,024 bits per second.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Kilobits per second.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ This is equivalent to 1,000 times faster than a standard 28.8 Kbps (thousand bits per second) telephone modem in a shared broadcast environment.
  • http://www.motorola.com/content.jsp?globalObjectId=7921-10345 18 January 2010 13:44 UTC www.motorola.com [Source type: General]

.For example, a 56k modem can transfer data at up to 56,000 bit/s (7 kB/s) over the phone line.^ How do I connect a modem to a phone line?
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ A modem is typically used to send digital data over a phone line .

^ Transfers the modem from data mode to command mode.

Passband modulation techniques
Analog modulation
AM · SSB  · QAM  · FM · PM · SM
Digital modulation
FSK · ASK · OOK · PSK · QAM
MSK · CPM · PPM · TCM
OFDM · SC-FDE
Spread spectrum
CSS  · DSSS  · FHSS  · THSS
See also: Demodulation, modem,
.In the summer of 1960, the name Data-Phone was introduced to replace the earlier term digital subset.^ Since the phone line was designed to carry tones, you should thus be able to carry digital data in the form of analog tones.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

The 202 Data-Phone was a half-duplex asynchronous service that was marketed extensively in late 1960. In 1962, the 201A and 201B Data-Phones were introduced. .They were synchronous modems using two-bit-per-baud phase-shift keying (PSK).^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This is equivalent to 1,000 times faster than a standard 28.8 Kbps (thousand bits per second) telephone modem in a shared broadcast environment.
  • http://www.motorola.com/content.jsp?globalObjectId=7921-10345 18 January 2010 13:44 UTC www.motorola.com [Source type: General]

.The 201A operated half-duplex at 2,000 bit/s over normal phone lines, while the 201B provided full duplex 2,400 bit/s service on four-wire leased lines, the send and receive channels running on their own set of two wires each.^ F1 = full duplex operation .
  • Modem Initialization String Codes 12 September 2009 15:13 UTC www.uic.edu [Source type: Reference]

^ Full or half duplex operation.
  • Modem Initialization String Codes 12 September 2009 15:13 UTC www.uic.edu [Source type: Reference]

^ She had a phone line connecting the two.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

.The famous Bell 103A dataset standard was also introduced by Bell Labs in 1962. It provided full-duplex service at 300 baud over normal phone lines.^ These models allow users to speak hand free over the phone line via its Full-Duplex Audio system.
  • Compatible voice modems for Advanced Phone Recorder 18 January 2010 13:44 UTC www.concelsys.com [Source type: Reference]

^ The Baud rate on a line indicates how many changes in tones per second there are; for example, on a 300 baud line there are 300 changes per second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ As a matter of fact, 9600 bps is guaranteed to work over all phone lines that adhere to the Bellcore Standard.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Frequency-shift keying was used with the call originator transmitting at 1,070 or 1,270 Hz and the answering modem transmitting at 2,025 or 2,225 Hz.^ Use answer frequencies when origi- nating a call.
  • Modem Initialization String Codes 12 September 2009 15:13 UTC www.uic.edu [Source type: Reference]

^ If a call is coming in, the modem will try to answer it.

^ Frequency Shift Keying modulation method.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.The readily available 103A2 gave an important boost to the use of remote low-speed terminals such as the KSR33, the ASR33, and the IBM 2741.^ This can be because your terminal or computer software program uses common default settings which may be the same as those of the remote modem.
  • Controlling your Modem with AT Commands 18 January 2010 13:44 UTC www.zoltrix.com [Source type: FILTERED WITH BAYES]

^ And because text-based AS/400 applications and reports are still heavily used throughout DataCard, it was also important to have the data available in a "green-screen" environment.

^ If you are using VoIP, you need to connect the voice modem LINE jack to a Voice Terminal/Adapter such as Motorola VT1005.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

.AT&T reduced modem costs by introducing the originate-only 113D and the answer-only 113B/C modems.^ As a result of the standards, cable modems will be able to be manufactured in significant quantities (since they will work with different cable companies' systems) and the cost will be reduced to that approximating a 'normal' telephone modem.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ The service costs tend to be only slightly more than the monthly charge for a dial-up 33.6 modem connection to an Internet Service Provider (ISP).
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Originator Detection Pattern, a bit sequence under V.42 transmitted by the originating modem to the receiving modem, and answered by an ADP. .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

Contents

The Carterfone decision

The Novation CAT acoustically coupled modem
.For many years, the Bell System (AT&T) maintained a monopoly on the use of its phone lines, allowing only Bell-supplied devices to be attached to its network.^ Command CS5500 Telephone Line Sharing System - 1 x 3 - Automatic, Semi-automatic - Telephone, Answering Machine, Fax Machine, Modem Use the ComSwitch 5500 fax switch to automatically route calls to your phone, answering machine, fax or modem - all on a single line!
  • MODEMS/CONNECTIVITY at Low Prices 18 January 2010 13:44 UTC www.keenzo.com [Source type: General]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ For example, if you use a voice mail system, the special tone indicating you have voice mail might make the line noisy even for outbound calls.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

.Before 1968, AT&T maintained a monopoly on what devices could be electrically connected to its phone lines.^ How do I connect a modem to a phone line?
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ If this gives you bad connections again, try the same things: different areas, different phone lines, differen't settings.
  • The Powerbook Zone 18 January 2010 13:44 UTC www.pbzone.com [Source type: General]

^ If you use a phone line that also has broadband connection like DSL, please make sure you dont connect your modem to the wrong jack that belongs to DSL connection.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

.This led to a market for 103A-compatible modems that were mechanically connected to the phone, through the handset, known as acoustically coupled modems.^ How do I connect a modem to a phone line?
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ If your modem is not 56K compatible, and you are having trouble connecting to a 56K system, you may need to put three or four commas after the phone number in the dialing string to force your modem to ignore the 56K wake-up tone.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

^ PC SMS Receiver PC SMS Receiver is a software which allows you to receive SMS messages through GSM/UMTS phone or modem connected to your computer via serial or USB cable or Bluetooth or Infrared(IR).
  • Modem Software - Modem Master ActiveX Component, Throttle 6.7.28.2008f, Turbo Connect, Virtual Null Modem 18 January 2010 13:44 UTC finaldownload.com [Source type: General]

Particularly common models from the 1970s were the Novation CAT and the Anderson-Jacobson, spun off from an in-house project at the Lawrence Livermore National Laboratory. Hush-a-Phone v. FCC was a seminal ruling in United States telecommunications law decided by the DC Circuit Court of Appeals on November 8, 1956. The District Court found that it was within the FCC's authority to regulate the terms of use of AT&T's equipment. .Subsequently, the FCC examiner found that as long as the device was not physically attached it would not threaten to degenerate the system.^ If the modem loses its stored initialization string, the only remedy is to physically disconnect the modem from the router and attach it to another device (such as an AUX port or a PC) to reinitialize.
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

.Later, in the Carterfone decision of 1968, the FCC passed a rule setting stringent AT&T-designed tests for electronically coupling a device to the phone lines.^ If this gives you bad connections again, try the same things: different areas, different phone lines, differen't settings.
  • The Powerbook Zone 18 January 2010 13:44 UTC www.pbzone.com [Source type: General]

^ Seconds later, the phone line went dead.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ It's the device that lets your computer communicate with ours over your phone line.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

.AT&T made these tests complex and expensive, so acoustically coupled modems remained common into the early 1980s.^ However, we have not tested these modems thoroughly.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ A: There is no modem built into these devices.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ When you choose to store an active profile into the modems nonvolatile memory, the chosen stored profile is made the same as the current active profile.
  • Controlling your Modem with AT Commands 18 January 2010 13:44 UTC www.zoltrix.com [Source type: FILTERED WITH BAYES]

In December 1972, Vadic introduced the VA3400. .This device was remarkable because it provided full duplex operation at 1,200 bit/s over the dial network, using methods similar to those of the 103A in that it used different frequency bands for transmit and receive.^ On a 2400 bit line, there are 4 frequencies in use: Originate 0, originate 1, Receive 0, Receive 1.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ It's all to do with the speed of the data channels (9.6 or 14.4), the number of channels they will allow you to use (4 or 6 total) and how they are split between receive and transmit (2 and 2 or 3 and 1, for example).
  • Ross Barkman's Home Page 18 January 2010 13:44 UTC www.taniwha.org.uk [Source type: FILTERED WITH BAYES]

^ On the surface, access to the Internet via cable networks appears to be the solution for all those who have suffered from slow access via dial-up modems.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

In November 1976, AT&T introduced the 212A modem to compete with Vadic. .It was similar in design to Vadic's model, but used the lower frequency set for transmission.^ Sometimes replaced by a similar model - newer, cheaper, but frequently lacking previously working features.
  • Compatible voice modems for Advanced Phone Recorder 18 January 2010 13:44 UTC www.concelsys.com [Source type: Reference]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This clock is derived from an oscillator, which oscillates at a set frequency, by using a programmable divider.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.It was also possible to use the 212A with a 103A modem at 300 bit/s.^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ I use fedora core 3.and the only thing which it displays id "UNABLE TO OPEN MODEM" try for free driver if possible.
  • Of Modems and Winmodems | TUX 18 January 2010 13:44 UTC www.tuxmagazine.com [Source type: General]

.According to Vadic, the change in frequency assignments made the 212 intentionally incompatible with acoustic coupling, thereby locking out many potential modem manufacturers.^ According to an eighth aspect of the invention, there is provided an ADSL modem wherein the message exchange by polling is preferably performed in the operating frequency band of an analog modem.
  • ADSL modem - US6778595 18 January 2010 13:44 UTC www.patents.com [Source type: Reference]

^ An ADSL modem according to claim 6, wherein the message exchange by polling is performed in the operating frequency band of an analog modem.
  • ADSL modem - US6778595 18 January 2010 13:44 UTC www.patents.com [Source type: Reference]

^ Because modem models change so frequently, we cannot provide a list of all the models that do work, we can only recommend that you simply "try it and see".
  • Voice Modems and Professional Telephony Hardware 12 September 2009 15:13 UTC www.nch.com.au [Source type: General]

.In 1977, Vadic responded with the VA3467 triple modem, an answer-only modem sold to computer center operators that supported Vadic's 1,200-bit/s mode, AT&T's 212A mode, and 103A operation.^ Ability of a modem that can operate at different speeds to fall back to its next lower speed if line conditions cannot support the higher speed.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ If you issue a +++ on the dialing modem followed by an ATO command and discover that your connection does not respond, the answering modem interpreted the +++ when it was echoed to you.
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

^ We only support Voicent 3025 Data/Fax/Voice PCI modem .
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

The Smartmodem and the rise of BBSes

US Robotics Sportster 14,400 Fax modem (1994)
.The next major advance in modems was the Smartmodem, introduced in 1981 by Hayes Communications.^ AMIT Community support + discussion for all modems from Advanced Multimedia Internet Technology Inc..

^ Zoom Community support + discussion for all modems from Hayes Microsystems, UK and Zoom Telephonics, Inc.

^ Hayes Community support + discussion for all modems from Hayes Microcomputer Co., Ltd., Hayes Microcomputer Products, Inc.

.The Smartmodem was an otherwise standard 103A 300-bit/s modem, but was attached to a small controller that let the computer send commands to it and enable it to operate the phone line.^ It's the device that lets your computer communicate with ours over your phone line.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ How do I connect a modem to a phone line?
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ Computers are Digital; phone lines are Analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.The command set included instructions for picking up and hanging up the phone, dialing numbers, and answering calls.^ Sets the delay to hang up after the disconnecting command is received.

^ Hang up and dial again.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ If your modem is not 56K compatible, and you are having trouble connecting to a 56K system, you may need to put three or four commas after the phone number in the dialing string to force your modem to ignore the 56K wake-up tone.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

.The basic Hayes command set remains the basis for computer control of most modern modems.^ Recall Stored Profiles This command instructs the modem chip set to go on-hook and restore the profile saved by the last &@ command.
  • Modem Commands | Tim's Computer Web Site 18 January 2010 13:44 UTC www.tbruce.com [Source type: Reference]

^ F1 factory hardware flow control defaults In addition to the initialization string, 3Com/USR modems require DIP switches to be properly set.
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

^ Click the Goto Download Page icon above for FMVSP56i Modem Drivers, specs, jumper settings, users & AT command manuals, pictures.
  • Zoltirx Modem Drivers 18 January 2010 13:44 UTC www.zoltrix.com [Source type: Academic]

.Prior to the Hayes Smartmodem, dial-up modems almost universally required a two-step process to activate a connection: first, the user had to manually dial the remote number on a standard phone handset, and then secondly, plug the handset into an acoustic coupler.^ Unlike a dial-up connection, it does not require a phone line.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ PPP Users A user dials into a modem pool using PPP to establish a network connection.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ Dial up Modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Hardware add-ons, known simply as dialers, were used in special circumstances, and generally operated by emulating someone dialing a handset.^ For example, when the modem line is shared with a regular phone, and someone is making a call using that line, then the modem will not be able to dial out.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ The hardware setup consists of a cable modem produced by LanCity or General Instruments which plugs into an ethernet card using a 10BaseT (UTP-45) cable.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Script for Samsung Phones (3kB): Samsung Script - generic script for normal dial-up operation (not GPRS or 1xRTT).
  • Ross Barkman's Home Page 18 January 2010 13:44 UTC www.taniwha.org.uk [Source type: FILTERED WITH BAYES]

.With the Smartmodem, the computer could dial the phone directly by sending the modem a command, thus eliminating the need for an associated phone instrument for dialing and the need for an acoustic coupler.^ If your modem is not 56K compatible, and you are having trouble connecting to a 56K system, you may need to put three or four commas after the phone number in the dialing string to force your modem to ignore the 56K wake-up tone.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ If you issue a +++ on the dialing modem followed by an ATO command and discover that your connection does not respond, the answering modem interpreted the +++ when it was echoed to you.
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

.The Smartmodem instead plugged directly into the phone line.^ You don’t plug it into the phone line!

^ Customer: "It has to be plugged into a phone jack?"
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ He had cleverly hooked his phone line from his new external modem directly into his old internal modem.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

This greatly simplified setup and operation. .Terminal programs that maintained lists of phone numbers and sent the dialing commands became common.^ Fast Connect function works well if you dial to the same phone number from only one place.
  • Lenovo Support & downloads - Lucent AMR Modem driver (CDC and Mini PCI) for Windows XP, 2000, Me, 98, 95, NT - ThinkPad 18 January 2010 13:44 UTC www-307.ibm.com [Source type: Reference]

^ In certain areas, you have to dial 10 digit phone numbers for local calls.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ Logical Modem Pools A logical modem pool is used to identify a modem pool by the phone number that is dialed to access it.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

The Smartmodem and its clones also aided the spread of bulletin board systems (BBSs). .Modems had previously been typically either the call-only, acoustically coupled models used on the client side, or the much more expensive, answer-only models used on the server side.^ The limit is set in the server-side modems.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ Hopefully those that do use USR modems use *only* USR modems to answer with.
  • The Powerbook Zone 18 January 2010 13:44 UTC www.pbzone.com [Source type: General]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

.The Smartmodem could operate in either mode depending on the commands sent from the computer.^ Note:  Sync/async interfaces require the physical-layer async configuration command in order to operate in asynchronous mode.
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

.There was now a low-cost server-side modem on the market, and the BBSs flourished.^ The limit is set in the server-side modems.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ Now that standards for Cable Modems have been agreed, their cost will decrease and they will be more readily available.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Note that there's now a Linux driver for the ACP (Mwave) modem used in IBM Thinkpads 600+.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

.Almost all modern modems also do double-duty as a fax machine as well.^ Fax Machine Got a scanner and a fax modem?
  • Modem Software - Modem Master ActiveX Component, Throttle 6.7.28.2008f, Turbo Connect, Virtual Null Modem 18 January 2010 13:44 UTC finaldownload.com [Source type: General]

^ The slot's main use is for HSF type modems where the CPU does almost all of the work.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ IBM Community support + discussion for all chipsets and modems from IBM Corp., International Business Machines Corp.

.Digital faxes, introduced in the 1980s, are simply a particular image format sent over a high-speed (commonly 14.4 kbit/s) modem.^ Zoltrix 14.4 fax modem .
  • Modem strings for Netlink 18 January 2010 13:44 UTC www.getinfo.net [Source type: Academic]

^ The PSK31 digital modem engine, however, requires intense DSP processing that is only commonly available in PC sound card.
  • NUE-PSK Digital Modem 18 January 2010 13:44 UTC www.nue-psk.com [Source type: General]

^ Spkrphn V.34 SPV.R 28.8 ISA Fax-Modem Card GSEP-2302 $14.00 .

.Software running on the host computer can convert any image into fax-format, which can then be sent using the modem.^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ Some of these modems may even crash your computer if you use them with PhoneSweep.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Such software was at one time an add-on, but since has become largely universal.

Softmodem (dumb modem)

.
A PCI Winmodem/Softmodem (on the left) next to a traditional ISA modem (on the right).
^ There are modems for PCI slots, other modems for the older ISA slots, and ARM software "modems" for the new small AMR slot.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ The Linux serial driver is being modified to support certain PCI modem cards (but not winmodems).
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ Sandstorm has tested a number of external modems, PCMCIA modems, and internal PCI/ISA modems to determine their compatibility with Single Call Detect™ and PhoneSweep version 4.4 and above.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

Notice the less complex circuitry of the modem on the left.
.A Winmodem or Softmodem is a stripped-down modem that replaces tasks traditionally handled in hardware with software.^ Virtual Modem PRO Virtual Modem PRO 3.0 creates software virtual IP-modems and maps them to virtual serial ports in Windows OS. The product was developed to emulate standard hardware modems.
  • Modem Software - Modem Master ActiveX Component, Throttle 6.7.28.2008f, Turbo Connect, Virtual Null Modem 18 January 2010 13:44 UTC finaldownload.com [Source type: General]

^ Basically, these newer models have built-in modem capability, unlike earlier ones that rely on the BlackBerry Windows software to handle modem commands.
  • Ross Barkman's Home Page 18 January 2010 13:44 UTC www.taniwha.org.uk [Source type: FILTERED WITH BAYES]

^ In the all-software modem, there are still two items handled by hardware: the A/D conversion of waveshapes by the codec and echo cancellation.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

.In this case the modem is a simple digital signal processor designed to create sounds, or voltage variations, on the telephone line.^ The modem will not work with a digital line.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ In the case where it is decided that data communication by another ADSL modem is occurring on the telephone line, an ADSL band signal detection signal is output from the symbol counter 28 and input to the line control unit 12 of the system shownin FIG. 1 thereby to generate a control signal.
  • ADSL modem - US6778595 18 January 2010 13:44 UTC www.patents.com [Source type: Reference]

^ While hardware modems used use DSPs (Digital Signal Processors) some of these DSPs are programmed by a driver which must be downloaded from the hard disk to the DSPs memory just before using the modem.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

.Softmodems are cheaper than traditional modems, since they have fewer hardware components.^ Sometimes referred to as software or controllerless modems, they tend to be less expensive than controller-based modems.
  • Of Modems and Winmodems | TUX 18 January 2010 13:44 UTC www.tuxmagazine.com [Source type: General]

^ As a result of the standards, cable modems will be able to be manufactured in significant quantities (since they will work with different cable companies' systems) and the cost will be reduced to that approximating a 'normal' telephone modem.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Without this signal, and with Hardware Flow Control, you will not be able to talk to the modem AT ALL, since your computer will refuse to talk to something that is not ready to listen!!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.One downside is that the software generating the modem tones is not simple, and the performance of the computer as a whole often suffers when it is being used.^ There is no standard interface so that different brands/models of software-modems need different drivers (unless the different brands/models happen to use the same chipset internally).
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ So if you use the modem a lot it's probably better to avoid all-software modems (and then you can use a less powerful CPU :-).
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ The hardware setup consists of a cable modem produced by LanCity or General Instruments which plugs into an ethernet card using a 10BaseT (UTP-45) cable.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

For online gaming this can be a real concern. .Another problem is lack of portability such that non-Windows operating systems (such as Linux) may not have an equivalent driver to operate the modem.^ System Requirements Windows 9x/2000/ME operating systems Pentium 166 MHz MMX-compatible PC or greater 16 M byte RAM or more .
  • Compatible voice modems for Advanced Phone Recorder 18 January 2010 13:44 UTC www.concelsys.com [Source type: Reference]

^ The serial port the the modem resides on does need a driver and it's supplied either as a Linux serial module or compiled into the kernel.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

^ Configuring them ranges from very easy (automatically) to difficult depending on both the modem, your skills, and how easy it is to find info about your modem --info that is not all in this HOWTO. Some of the modems which will work only under MS Windows due to lack of Linux drivers (for software modems).
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

Narrow-band/phone-line dialup modems

.A standard modem of today contains two functional parts: an analog section for generating the signals and operating the phone, and a digital section for setup and control.^ This signal is analog, and therefore the phone line is analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Computers are Digital; phone lines are Analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ While hardware modems used use DSPs (Digital Signal Processors) some of these DSPs are programmed by a driver which must be downloaded from the hard disk to the DSPs memory just before using the modem.
  • Modem-HOWTO : Modems for a Linux PC 18 January 2010 13:44 UTC www.linuxselfhelp.com [Source type: FILTERED WITH BAYES]

This functionality is actually incorporated into a single chip, but the division remains in theory. .In operation the modem can be in one of two modes, data mode in which data is sent to and from the computer over the phone lines, and command mode in which the modem listens to the data from the computer for commands, and carries them out.^ This takes the modem out of command mode.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ How do I connect a modem to a phone line?
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ These tones are sent over the phone line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.A typical session consists of powering up the modem (often inside the computer itself) which automatically assumes command mode, then sending it the command for dialing a number.^ This takes the modem out of command mode.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Dial up Modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Dial-up Modem 33.6Kbps .
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

.After the connection is established to the remote modem, the modem automatically goes into data mode, and the user can send and receive data.^ PPP Users A user dials into a modem pool using PPP to establish a network connection.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ Once the modem connection has been established, the NAS sends a text welcome banner to the user.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.When the user is finished, the escape sequence, "+++" followed by a pause of about a second, is sent to the modem to return it to command mode, and the command ATH to hang up the phone is sent.^ This takes the modem out of command mode.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ If the NAS can not authenticate the user the NAS will hang up on them.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

.The commands themselves are typically from the Hayes command set, although that term is somewhat misleading.^ A complete summary and explanation of the AT command set for Hayes compatible dial-up modems is given on this page.

.The original Hayes commands were useful for 300 bit/s operation only, and then extended for their 1,200 bit/s modems.^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Faster speeds required new commands, leading to a proliferation of command sets in the early 1990s.^ This ensures that the modem always talks at the expected speed regardless of the speed of any incoming modem connection (if you set the modem to lock on the DTE speed, which is required ).
  • Modem-Router Connection Guide  [Asynchronous Connections] - Cisco Systems 18 January 2010 13:44 UTC www.cisco.com [Source type: Reference]

.Things became considerably more standardized in the second half of the 1990s, when most modems were built from one of a very small number of chipsets.^ On most modems there is more than one AT&F option nowadays.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ One more interesting thing.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ I want to ask one more thing.
  • Everything About BSNL EvDO Data Card | Gaurish Sharma Live 18 September 2009 5:38 UTC www.gaurishsharma.com [Source type: General]

.We call this the Hayes command set even today, although it has three or four times the numbers of commands as the actual standard.^ Sometimes although the model number did not even change, what was actually in the box did.
  • Compatible voice modems for Advanced Phone Recorder 18 January 2010 13:44 UTC www.concelsys.com [Source type: Reference]

^ When set to 1, all responses to commands will be sent as verbal messages, such as OK and ERROR. When set to V0, only a number will be returned.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Sets your PC's clock by modem to the exact time by calling an atomic clock (usually long-distance) or to the nearest minute by calling a CompuServ .
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

Increasing speeds (V.21, V.22, V.22bis)

A 2,400 bit/s modem for a laptop.
.The 300 bit/s modems used audio frequency-shift keying to send data.^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ In this case, we will need to add a notifier to let the modems know we will start sending data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.In this system the stream of 1s and 0s in computer data is translated into sounds which can be easily sent on the phone lines.^ These tones are sent over the phone line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Computers are Digital; phone lines are Analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ With Error correction and data compression, the links between two modems are synchronous, so we will need a UART in the modem as well, to translate the Asynchronous data from the computer into Synchronous data on the line, and vice versa.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.In the Bell 103 system the originating modem sends 0s by playing a 1,070 Hz tone, and 1s at 1,270 Hz, with the answering modem putting its 0s on 2,025 Hz and 1s on 2,225 Hz.^ Answer will send the Modem tone, then it will send an unmodulated carrier.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ If your modem is not 56K compatible, and you are having trouble connecting to a 56K system, you may need to put three or four commas after the phone number in the dialing string to force your modem to ignore the 56K wake-up tone.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.These frequencies were chosen carefully, they are in the range that suffer minimum distortion on the phone system, and also are not harmonics of each other.^ They gave me a "SMC EtherEZ" ISA card, but I've seen them install totally different cards in other systems.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ These models allow users to speak hand free over the phone line via its Full-Duplex Audio system.
  • Compatible voice modems for Advanced Phone Recorder 18 January 2010 13:44 UTC www.concelsys.com [Source type: Reference]

^ The frequencies are usually staggered to reduce the chance that a harmonic of one frequency (or a combination of sending and receiving frequencies) is incorrectly detected as the other frequency.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

.In the 1,200 bit/s and faster systems, phase-shift keying was used.^ Similar to the transmission method used in FM radio, bits (and later Symbols) are represented as deviations in the phase of a constant frequency carrier.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ So, both the modem and the computer should use 8450 UARTs, or their 16 bit brothers, the Intel 16450 or the 16550, which has a top speed of 115,200 bps.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ AM forms the basis of several different modem transmission systems, but is always used in conjunction with another technique, such as Phase Encoding.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

.In this system the two tones for any one side of the connection are sent at the similar frequencies as in the 300 bit/s systems, but slightly out of phase.^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ In FSK, the presence of one frequency tone represents a "1" and the presence of another frequency represents a "0".
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ What we are already doing though, is sending more than one tone at once; we have one tone for each of the two modems.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.By comparing the phase of the two signals, 1s and 0s could be pulled back out, for instance if the signals were 90 degrees out of phase, this represented two digits, 1, 0, at 180 degrees it was 1, 1.^ The modem on the other end listens; it picks up the tones, and transforms them back into digital signals that get sent to a computer.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ In this system, Symbols are represented by changes in the phase of the carrier, comparing its current state against its previous phase.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ In a computer for example, a digital signal is represented by the presence or lack of an electrical current.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.In this way each cycle of the signal represents two digits instead of one.^ An unaltered signal represents the same bit value as the last bit, while a 50% reduction in frequency for one Hz period of the base frequency indicates that the next bit has a value opposite that of the last bit.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ In a computer for example, a digital signal is represented by the presence or lack of an electrical current.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Not synonymous with bits per second since signals can represent more than one bit.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.1,200 bit/s modems were, in effect, 600 symbols per second modems (600 baud modems) with 2 bits per symbol.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Send and receive speed is shown in 'thousands of bits per seconds' also expressed as Kpbs.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ The bits per Second rate explains how many bits can go over the line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Voiceband modems generally remained at 300 and 1,200 bit/s (V.21 and V.22) into the mid 1980s.^ So, both the modem and the computer should use 8450 UARTs, or their 16 bit brothers, the Intel 16450 or the 16550, which has a top speed of 115,200 bps.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.A V.22bis 2,400-bit/s system similar in concept to the 1,200-bit/s Bell 212 signalling was introduced in the U.S., and a slightly different one in Europe.^ An unaltered signal represents the same bit value as the last bit, while a 50% reduction in frequency for one Hz period of the base frequency indicates that the next bit has a value opposite that of the last bit.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ The computers we use today, use all RS-232 signaling with a slightly different voltage level for Signals.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ AM by itself represents different bits (or symbols) as different signal amplitudes.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

.By the late 1980s, most modems could support all of these standards and 2,400-bit/s operation was becoming common.^ Ability of a modem that can operate at different speeds to fall back to its next lower speed if line conditions cannot support the higher speed.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ These words were picked since they describe the actions a modem takes in the most precise way.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.For more information on baud rates versus bit rates, see the companion article list of device bandwidths.^ For more details, please see the Voicent online knowledge base article: Forcing Windows to recognize a voice mode .
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ A device that can transmit data at a rate of 33,600 bits per second which is equivalent to 4200 characters per second .
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Users see important information about the DSL connection, devices on the network, firewall logs, and more.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

Increasing speeds (one-way proprietary standards)

.Many other standards were also introduced for special purposes, commonly using a high-speed channel for receiving, and a lower-speed channel for sending.^ The foundation of many high speed transmission systems, Symbols are encoded as deviations in the phase and amplitude of the carrier.
  • Data/FAX Modem Transmission Modulation Systems 18 January 2010 13:44 UTC nemesis.lonestar.org [Source type: Reference]

^ On the other hand, most telephone subscribers have old 'copper cable' connecting them to their telephone company's high speed network.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ A widely used proprietary standard providing error correction [MNP 2,3, 4 and 10] and 2:1 data compression [MNP 5 & 7], and enhanced capability (MNP 10 for adverse channel reliability / MNP10EC) commonly used by cellular modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.One typical example was used in the French Minitel system, in which the user's terminals spent the majority of their time receiving information.^ For more information on how users can establish a PPP connection using PAP, please refer to http://www.more.net/refdesk and under Documents & Software select the client operating system.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ For example, if you use a voice mail system, the special tone indicating you have voice mail might make the line noisy even for outbound calls.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ We spent a great deal of time switching all of our customers to the new system.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

.The modem in the Minitel terminal thus operated at 1,200 bit/s for reception, and 75 bit/s for sending commands back to the servers.^ Command set interface between data terminal, CCITT, Dial and Leased, equipment (DTE) and data circuit terminating, Line Modems, equipment DCE) .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Any use of a server type application or service on a computer system connected to 21st Century Cable Modem Service is prohibited and may result in termination of 21st Century Cable Modem Service (i.e.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ So, both the modem and the computer should use 8450 UARTs, or their 16 bit brothers, the Intel 16450 or the 16550, which has a top speed of 115,200 bps.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Three U.S. companies became famous for high-speed versions of the same concept.^ On the other hand, most telephone subscribers have old 'copper cable' connecting them to their telephone company's high speed network.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Comparisons are further confused by the fact that not all Cable Companies provide the same Internet access speeds.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

^ Cable Companies can provide Internet access in two ways - either by a 'telephone dial-up type' of service or by a new high speed connection.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

.Telebit introduced its Trailblazer modem in 1984, which used a large number of 36 bit/s channels to send data one-way at rates up to 18,432 bit/s.^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ This is done by sending one bit to start, a Start Bit.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ We call this number the Data bits.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.A single additional channel in the reverse direction allowed the two modems to communicate how much data was waiting at either end of the link, and the modems could change direction on the fly.^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Taicom Community support + discussion for all modems from Taicom Data Systems Co., Ltd..

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.The Trailblazer modems also supported a feature that allowed them to spoof the UUCP g protocol, commonly used on Unix systems to send e-mail, and thereby speed UUCP up by a tremendous amount.^ Ability of a modem that can operate at different speeds to fall back to its next lower speed if line conditions cannot support the higher speed.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ The modems themselves used the same protocol on the DCE channel, but this control is usually out of the users' hands.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This is also the maximum time a modem pool text user or a user who telnet's to the unix server is allowed per call or telnet session.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

Trailblazers thus became extremely common on Unix systems, and maintained their dominance in this market well into the 1990s.
U.S. Robotics (USR) introduced a similar system, known as HST, although this supplied only 9,600 bit/s (in early versions at least) and provided for a larger backchannel. .Rather than offer spoofing, USR instead created a large market among Fidonet users by offering its modems to BBS sysops at a much lower price, resulting in sales to end users who wanted faster file transfers.^ This continues until the number of modems in use are less than the number of modems in use where strict time limits are enforced or there are no users on the modem pool who have exceeded their Modem Pool per call Time Limit.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ This is also the maximum time a modem pool text user or a user who telnet's to the unix server is allowed per call or telnet session.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ Data summarizing the monthly usage for each user is recorded and stored in a zip file that is named [CinName].modem.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

.Hayes was forced to compete, and introduced its own 9,600-bit/s standard, Express 96 (also known as Ping-Pong), which was generally similar to Telebit's PEP. Hayes, however, offered neither protocol spoofing nor sysop discounts, and its high-speed modems remained rare.^ Info on high speed modems for sysops and users.
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ The monthly fee already includes Cable Modem rental and they offer 2 connection speed plans ( 512k/128k and 2Mbps/256K ).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Send and receive speed is shown in 'thousands of bits per seconds' also expressed as Kpbs.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

4,800 and 9,600 bit/s (V.27ter, V.32)

Echo cancellation was the next major advance in modem design. .Local telephone lines use the same wires to send and receive, which results in a small amount of the outgoing signal bouncing back.^ A device that transmits and receives computer data through a communications channel such as radio, telephone lines, or cellular phones.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ NOTE: If an NAS uses digital phone lines, like the cisco AS5200, all 24 or 48 modems have to belong to the same logical modem pool.
  • MOREnet - kinetic Resources - Modem Pool Reference 18 January 2010 13:44 UTC kinetic.more.net [Source type: Reference]

^ On a 2400 bit line, there are 4 frequencies in use: Originate 0, originate 1, Receive 0, Receive 1.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

This signal can confuse the modem. .Is the signal it is receiving a data transmission from the remote modem, or its own transmission bouncing back?^ The process of two modems exchanging information via predetermined signals on how they will send data to one another, such as transmission speed, size of data packets, whether the operation will be full- or half-duplex, etc.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ So, instead of trying to cram everything into the data stream, we have defined a set of electrical signals that can go to and from the modem and computer to let the other know what is happening.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ All these signals, as well as the standard way of sending and receiving data, are grouped together in a protocol which we know as RS-232.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.This was why earlier modems split the signal frequencies into answer and originate; each modem simply didn't listen to its own transmitting frequencies.^ Without this signal, and with Hardware Flow Control, you will not be able to talk to the modem AT ALL, since your computer will refuse to talk to something that is not ready to listen!!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Answer modem) things go fine, when Originating (i.e.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ So, instead of trying to cram everything into the data stream, we have defined a set of electrical signals that can go to and from the modem and computer to let the other know what is happening.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Even with improvements to the phone system allowing higher speeds, this splitting of available phone signal bandwidth still imposed a half-speed limit on modems.^ The process of two modems exchanging information via predetermined signals on how they will send data to one another, such as transmission speed, size of data packets, whether the operation will be full- or half-duplex, etc.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Ability of a modem that can operate at different speeds to fall back to its next lower speed if line conditions cannot support the higher speed.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Time Community support + discussion for all modems supplied with computers from General Computers Limited, Granville Computer Systems Limited and Time Group Ltd..

Echo cancellation got around this problem. .Measuring the echo delays and magnitudes allowed the modem to tell if the received signal was from itself or the remote modem, and create an equal and opposite signal to cancel its own.^ Data Set Ready, DSR. This signal is controlled by the DCE. It tells the DTE that the Equipment (Modem) is available and functioning to receive data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Modems were then able to send over the whole frequency spectrum in both directions at the same time, leading to the development of 4,800 and 9,600 bit/s modems.^ Your IP address and the modem IP address are on the same network and have the same network mask (in my case 255.255.255.0 -- 24 bits).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ So, both the modem and the computer should use 8450 UARTs, or their 16 bit brothers, the Intel 16450 or the 16550, which has a top speed of 115,200 bps.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Both the Sending and Receiving carrier will exist at any given time on a connection, on the modem connections we deal with today.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Increases in speed have used increasingly complicated communications theory. .1,200 and 2,400 bit/s modems used the phase shift key (PSK) concept.^ She wrote down the information and gave it to me, including the modem settings to use: 8 data bits, no parody, and 1 thought bit.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ Notes from Dallas, TX or anyone using Motorola CyberSurfr If you have a Motorola CyberSurfr cable modem you will need to press the reset key on the back of the modem if you switch network cards.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ So, both the modem and the computer should use 8450 UARTs, or their 16 bit brothers, the Intel 16450 or the 16550, which has a top speed of 115,200 bps.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.This could transmit two or three bits per symbol.^ The number of binary digits or bits transmitted per second.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ A device that can transmit data at a rate of 33,600 bits per second which is equivalent to 4200 characters per second .
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

The next major advance encoded four bits into a combination of amplitude and phase, known as Quadrature Amplitude Modulation (QAM). Best visualized as a constellation diagram, the bits are mapped onto points on a graph with the x (real) and y (quadrature) coordinates transmitted over a single carrier.
.The new V.27ter and V.32 standards were able to transmit 4 bits per symbol, at a rate of 1,200 or 2,400 baud, giving an effective bit rate of 4,800 or 9,600 bit/s.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The bits per Second rate explains how many bits can go over the line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ A device that can transmit data at a rate of 33,600 bits per second which is equivalent to 4200 characters per second .
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

The carrier frequency was 1,650 Hz. .For many years, most engineers considered this rate to be the limit of data communications over telephone networks.^ Network conditions and environmental factors, including volume of network traffic, building materials and construction, and network overhead, lower actual data throughput rate.
  • D-Link Wireless G ADSL Router Modem 18 January 2010 13:44 UTC www.dlink.com [Source type: General]
  • D-Link Wireless G ADSL Router Modem 18 January 2010 13:44 UTC www.dlink.com [Source type: General]

^ The Wireless Router complies with the IEEE802.11g/b standards so that the data transmission rate is up to 54Mbps.In the most attentive wireless security, The Wireless Router provides multiple protection measures.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

^ Support for G.lite and full-rate DSL ensures compatibility with most DSL networks.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

Error correction and compression
.Operations at these speeds pushed the limits of the phone lines, resulting in high error rates.^ These tones are sent over the phone line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Now that there are more things that can be done whilst making a connection, more speeds, line equalization, error correction and compression, things are becoming a bit more complicated when we make a connection..
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ But to do so, they will need some time and a little data to play with, so they need to be talking to the computer at higher speeds than they are on the line, assuming that they can compress the data and no errors occur.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.This led to the introduction of error-correction systems built into the modems, made most famous with Microcom's MNP systems.^ MNP error correction protocols .
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ With Error correction and data compression, the links between two modems are synchronous, so we will need a UART in the modem as well, to translate the Asynchronous data from the computer into Synchronous data on the line, and vice versa.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.A string of MNP standards came out in the 1980s, each increasing the effective data rate by minimizing overhead, from about 75% theoretical maximum in MNP 1, to 95% in MNP 4. The new method called MNP 5 took this a step further, adding data compression to the system, thereby increasing the data rate above the modem's rating.^ Operating over 2-wire, 4-wire and 8-wire, the DSL modems provide voice and data transmission at variable data rates, from 64 kbps to 22.2 Mbps, over distances up to 10 km.
  • DSL Modems - RAD 18 January 2010 13:44 UTC www.rad.com [Source type: News]

^ Network conditions and environmental factors, including volume of network traffic, building materials and construction, and network overhead, lower actual data throughput rate.
  • D-Link Wireless G ADSL Router Modem 18 January 2010 13:44 UTC www.dlink.com [Source type: General]
  • D-Link Wireless G ADSL Router Modem 18 January 2010 13:44 UTC www.dlink.com [Source type: General]

^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.Generally the user could expect an MNP5 modem to transfer at about 130% the normal data rate of the modem.^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Customer: "I'm thinking about getting a T1 modem, and I was wondering where I could purchase one and how much it would cost?"
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ Customer : "I'm thinking about getting a T1 modem, and I was wondering where I could purchase one and how much it would cost?"
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

.Details of MNP were later released and became popular on a series of 2,400-bit/s modems, and ultimately led to the development of V.42 and V.42bis ITU standards.^ So modem manufacturers got together and upgraded MNP-4 to MNP-5, and V.42 to V.42Bis.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ MNP/V.42 and MNP/V.42bis Commands .
  • Modem Commands | Tim's Computer Web Site 18 January 2010 13:44 UTC www.tbruce.com [Source type: Reference]

^ InitString=AT&F&C1&D3\J0\N3\Q2\V2%C1"H3S7=60 BPS=38400 Intel SatisFAXtion Modem/400 and 400e (V.42bis) .
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

.V.42 and V.42bis were non-compatible with MNP but were similar in concept: Error correction and compression.^ MNP error correction protocols .
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ ATI 2400etc V.42 - non-MNP mode AT&F&C1 &D2 X6 S7=60 S11=60 .

^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Another common feature of these high-speed modems was the concept of fallback, or speed hunting, allowing them to talk to less-capable modems.^ Depending on the speed the modem is trying to talk at, this tone will have a different pitch.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Modems without compression often do not talk faster than their top speed, or the next 'notch' over it (i.e.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The bottom line is that having high speed cable modem access to the Internet will ensure that any data coming down to your computer will be by the fastest possible means.
  • VICOMSOFT: Knowledgeshare - Cable Modems 12 September 2009 15:13 UTC www.vicomsoft.com [Source type: General]

.During the call initiation the modem would play a series of signals into the line and wait for the remote modem to respond to them.^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ For example, when the modem line is shared with a regular phone, and someone is making a call using that line, then the modem will not be able to dial out.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ He had cleverly hooked his phone line from his new external modem directly into his old internal modem.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

.They would start at high speeds and progressively get slower and slower until they heard an answer.^ I have few questions, I heard from few people about the speeds they received … .
  • Everything About BSNL EvDO Data Card | Gaurish Sharma Live 18 September 2009 5:38 UTC www.gaurishsharma.com [Source type: General]

^ I have few questions, I heard from few people about the speeds they received in torrents.
  • Everything About BSNL EvDO Data Card | Gaurish Sharma Live 18 September 2009 5:38 UTC www.gaurishsharma.com [Source type: General]

^ Speaking of problems: We did not even agree yet on how many bits we would send between Start and Stop, and what speed we would send bits on!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Thus, two USR modems would be able to connect at 9,600 bit/s, but, when a user with a 2,400-bit/s modem called in, the USR would fallback to the common 2,400-bit/s speed.^ The monthly fee already includes Cable Modem rental and they offer 2 connection speed plans ( 512k/128k and 2Mbps/256K ).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Now that there are more things that can be done whilst making a connection, more speeds, line equalization, error correction and compression, things are becoming a bit more complicated when we make a connection..
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.This would also happen if a V.32 modem and a HST modem were connected.^ His modem was dialing but it would not make the connection, stopping before it prompted him for his username.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ I explained to her that in order to connect our computer to the phone line, we would need a modem.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ This manual contains operating instructions for courier v.32 bis, courier hst and courier hst dual standard modems.
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

.Because they used a different standard at 9,600 bit/s, they would fall back to their highest commonly supported standard at 2,400 bit/s.^ Both Fall back and Fall Forward sequences are controlled by the modems; both sides of the line must support this feature for it to work.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Some voice modems do not support standard voice device driver interface even though they claim to be voice capable.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

^ It makes me wish that I would have stayed with ATTWS a while back since it doesn't look like they have these problems.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.The same applies to V.32bis and 14,400 bit/s HST modem, which would still be able to communicate with each other at only 2,400 bit/s.^ This modem a bit “old” but I still using it.
  • Default Modem Password 18 January 2010 13:44 UTC koneksen.com [Source type: FILTERED WITH BAYES]

^ The modem is for telephone communication only."
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ Longshine Community support + discussion for all Aries, Shine and other modems from Long Vision International Co.

Breaking the 9.6k barrier

.In 1980, Gottfried Ungerboeck from IBM Zurich Research Laboratory applied powerful channel coding techniques to search for new ways to increase the speed of modems.^ It is a very fast and flexible 2-way cable modem with initial speed of 512 kb/s but it can be set up to 10Mb/s by the cable provider.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

His results were astonishing but only conveyed to a few colleagues[1]. Finally in 1982, he agreed to publish what is now a landmark paper in the theory of information coding..February 2008" style="white-space:nowrap;">[citation needed] By applying powerful parity check coding to the bits in each symbol, and mapping the encoded bits into a two-dimensional diamond pattern, Ungerboeck showed that it was possible to increase the speed by a factor of two with the same error rate.^ And not every error can be caught by Parity checks at higher speeds.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Check to make 100% sure you have your software set for 8 Databits, No Parity, and One Stop Bit.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ I checked the terminal settings (baud rate, parity, etc), all correct.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

The new technique was called mapping by set partitions (now known as trellis modulation).
.Error correcting codes, which encode code words (sets of bits) in such a way that they are far from each other, so that in case of error they are still closest to the original word (and not confused with another) can be thought of as analogous to sphere packing or packing pennies on a surface: the further two bit sequences are from one another, the easier it is to correct minor errors.^ The process of two modems exchanging information via predetermined signals on how they will send data to one another, such as transmission speed, size of data packets, whether the operation will be full- or half-duplex, etc.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ What the computers will do is add in one extra bit to each set of data; this is called the parity bit.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Now that there are more things that can be done whilst making a connection, more speeds, line equalization, error correction and compression, things are becoming a bit more complicated when we make a connection..
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]


V.32bis was so successful that the older high-speed standards had little to recommend them. .USR fought back with a 16,800 bit/s version of HST, while AT&T introduced a one-off 19,200 bit/s method they referred to as V.32ter (also known as V.32 terbo or tertiary), but neither non-standard modem sold well.^ I asked him a bit about his new modem as well as his old one.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ But they are not always able to avoid interaction with non-standard protocols!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Some voice modems do not support standard voice device driver interface even though they claim to be voice capable.
  • Voicent Voice Modem - FAQ 18 January 2010 13:44 UTC www.voicent.com [Source type: General]

V.34/28.8k and 33.6k
An ISA modem manufactured to conform to the V.34 protocol.
Any interest in these systems was destroyed during the lengthy introduction of the 28,800 bit/s V.34 standard. While waiting, several companies decided to release hardware and introduced modems they referred to as V.FAST. .In order to guarantee compatibility with V.34 modems once the standard was ratified (1994), the manufacturers were forced to use more flexible parts, generally a DSP and microcontroller, as opposed to purpose-designed ASIC modem chips.^ A lot of modems use Rockwell Chips.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

Today, the ITU standard V.34 represents the culmination of the joint efforts. It employs the most powerful coding techniques including channel encoding and shape encoding. .From the mere 4 bits per symbol (9.6 kbit/s), the new standards used the functional equivalent of 6 to 10 bits per symbol, plus increasing baud rates from 2,400 to 3,429, to create 14.4, 28.8, and 33.6 kbit/s modems.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ U.S.Robotics Press Release (02/28/94) Information about the new line of courier modems that will support the V.34 (V.FAST Standard) and these other standards: 14.4k V.32bis 16.8k HST 19.2k V.terbo 21.6k HST/V.terbo 28.8k V.FC (V. .
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ The bits per Second rate explains how many bits can go over the line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

This rate is near the theoretical Shannon limit. When calculated, the Shannon capacity of a narrowband line is \scriptstyle Bandwidth * log_2 (1 + P_u/P_n), with \scriptstyle P_u/P_n the signal-to-noise ratio. .Narrowband phone lines have a bandwidth from 300-3,100 Hz, so using \scriptstyle P_u/P_n=10,000: capacity is approximately 35 kbit/s.^ Wire gateways increase wireless bandwidth by using a high-powered transmitter that can be configured at levels from 100 to 400mW of power.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

^ Look at the S switches that set the time you will try to retrain, make sure there is no one picking up the phone on the line you are using.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ TV cable is used for downloading while phone line is used for uploading.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

Without the discovery and eventual application of trellis modulation, maximum telephone rates would have been limited to 3,429 baud * 4 bit/symbol == approximately 14 kbit/s using traditional QAM.
V.61/V.70 Analog/Digital Simultaneous Voice and Data
The V.61 Standard introduced Analog Simultaneous Voice and Data (ASVD). .This technology allowed users of v.61 modems to engage in point-to-point voice conversations with each other while their respective modems communicated.^ Qcom Community support + discussion for all modems from Qcom Technology, Inc..

^ Longshine Community support + discussion for all Aries, Shine and other modems from Long Vision International Co.

^ Diamond Community support + discussion for all SupraExpress and other modems from Diamond Multimedia Systems, Inc., SONICblue, Inc.

In 1995, the first DSVD (Digital Simultaneous Voice and Data) modems became available to consumers, and the standard was ratified as v.70 by the International Telecommunication Union (ITU) in 1996.
.Two DSVD modems can establish a completely digital link between each other over standard phone lines.^ The rate at which modems communicate over a phone line.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ She had a phone line connecting the two.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ Computers are Digital; phone lines are Analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Sometimes referred to as "the poor man's ISDN," and employing a similar technology, v.70 compatible modems allow for a maximum speed of 33.6 kbps between peers. .By using a majority of the bandwidth for data and reserving part for voice transmission, DSVD modems allow users to pick up a telephone handset interfaced with the modem, and initiate a call to the other peer.^ Used in dial up modems and other DCEs using the cellular telephone network .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ The only additional parts needed to implement a complete, full-featured system are external memory chips and a telephone line interface.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

One practical use for this technology was realized by early two player video gamers, who could hold voice communication with each other while in game over the PSTN.
.Advocates of DSVD envisioned whiteboard sharing and other practical applications for the standard, however, with advent of cheaper 56kbps analog modems intended for internet connectivity, peer-to-peer data transmission over the PSTN became quickly irrelevant.^ Also monitors connections initiated by other applications.
  • Modem downloads at VicMan 18 January 2010 13:44 UTC www.vicman.net [Source type: General]

^ A much more, technically correct definition is given below:- Evolution-Data Optimized(Evdo) is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access.
  • Everything About BSNL EvDO Data Card | Gaurish Sharma Live 18 September 2009 5:38 UTC www.gaurishsharma.com [Source type: General]

^ There are many old communication applications that require a direct modem connection.
  • Modem downloads at VicMan 18 January 2010 13:44 UTC www.vicman.net [Source type: General]

.Also, the standard was never expanded to allow for the making or receiving of arbitrary phone calls while the modem was in use, due to the cost of infrastructure upgrades to telcos, and the advent of ISDN and DSL technologies which effectively accomplished the same goal.^ Laptop using Cell Phone as Modem .
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ This modem can NOT be placed into a 12-modem rack This modem is unusual in that it is the only known modem which can be used in multiple countries by changing an AT command string to designate the recipient country of each phone call.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ The modems themselves used the same protocol on the DCE channel, but this control is usually out of the users' hands.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Today, Multi-Tech is the only known company to continue to support a v.70 compatible modem.^ Tech Support: "Your modem, sir.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ Tech Support : "What type of modem do you have?"
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ Tech Support: "What type of modem do you have?"
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

.While their device also offers v.92 at 56kbps, it remains significantly more expensive than comparable modems sans v.70 support.^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ V.92 modems: Sandstorm has added support for some V.92 modems listed below with our new version of PhoneSweep, version 5.0.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

^ On most modems there is more than one AT&F option nowadays.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Using digital lines and PCM (V.90/92)

Modem bank at an ISP.
.In the late 1990s Rockwell and U.S. Robotics introduced new technology based upon the digital transmission used in modern telephony networks.^ Microcom Networking Protocol - Class 4: Configures the modem to use error correction by resending blocks of data that are corrupted during transmission.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ DPL technology provides the transmission of data to users over the same lines that bring electric power to homes and businesses using TCP/IP protocol.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

.The standard digital transmission in modern networks is 64 kbit/s but some networks use a part of the bandwidth for remote office signaling (eg to hang up the phone), limiting the effective rate to 56 kbit/s DS0.^ USB Connection Some Gateways will have a Universal Serial Bus (USB) connection that can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Look at the S switches that set the time you will try to retrain, make sure there is no one picking up the phone on the line you are using.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.This new technology was adopted into ITU standards V.90 and is common in modern computers.^ Then the technique was adopted into the V.42 national standard.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.The 56 kbit/s rate is only possible from the central office to the user site (downlink) and in the United States, government regulation limits the maximum power output to only 53.3 kbit/s.^ Not so cheap : for small office use, same as 1) but not limited to 1 user and more speed TO internet.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.The uplink (from the user to the central office) still uses V.34 technology at 33.6k.^ Not so cheap : for small office use, same as 1) but not limited to 1 user and more speed TO internet.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ DPL technology provides the transmission of data to users over the same lines that bring electric power to homes and businesses using TCP/IP protocol.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

.Later in V.92, the digital PCM technique was applied to increase the upload speed to a maximum of 48 kbit/s, but at the expense of download rates.^ Its maximum speed is 110kbps and its upload & download speed run between 11kbps to 45 kbps.
  • Everything About BSNL EvDO Data Card | Gaurish Sharma Live 18 September 2009 5:38 UTC www.gaurishsharma.com [Source type: General]

For example a 48 kbit/s upstream rate would reduce the downstream as low as 40 kbit/s, due to echo on the telephone line. .To avoid this problem, V.92 modems offer the option to turn off the digital upstream and instead use a 33.6 kbit/s analog connection, in order to maintain a high digital downstream of 50 kbit/s or higher.^ I told her to turn her modem off and then back on.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ Modem strings for Netlink If you are having problems connecting to the internet, these are some of the more popular modems and their init strings that seem to work well.
  • Modem strings for Netlink 18 January 2010 13:44 UTC www.getinfo.net [Source type: Academic]

^ The monthly fee already includes Cable Modem rental and they offer 2 connection speed plans ( 512k/128k and 2Mbps/256K ).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.(See November and October 2000 update at http://www.modemsite.com/56k/v92s.asp ) V.92 also adds two other features.^ Information about the `Shaw@Home' service can be found at http://shaw.home.com General information about Shaw Cable can be found at http://www.shaw.ca .
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Information about ATT Broadband can be found at http://www.broadband.att.com .
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ At the time of speaking, SwissOnLine HiSpeed provide COM-21 modems (http://www.com21.com) complete with two different kinds of Antanae leads and an antenna splitter.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.The first is the ability for users who have call waiting to put their dial-up Internet connection on hold for extended periods of time while they answer a call.^ When I connected on the Internet for the first time, however, the dial tone came through the speakers.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC ops.tamu.edu [Source type: General]

^ If your modem is not 56K compatible, and you are having trouble connecting to a 56K system, you may need to put three or four commas after the phone number in the dialing string to force your modem to ignore the 56K wake-up tone.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

^ This way, if someone picks up a telephone, or a call-waiting tone is received, modems may retrain and stay online, instead of loosing a connection.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.The second feature is the ability to quickly connect to one's ISP. This is achieved by remembering the analog and digital characteristics of the telephone line, and using this saved information to reconnect at a fast pace.^ So what is Analog and what is Digital, and what is the advantage of one over the other?
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Computers are Digital; phone lines are Analog.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The only additional parts needed to implement a complete, full-featured system are external memory chips and a telephone line interface.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

Using compression to exceed 56k

.Today's V.42, V.42bis and V.44 standards allow the modem to transmit data faster than its basic rate would imply.^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Some modems that are 14400 will not talk faster or slower than 14400.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Modems without compression often do not talk faster than their top speed, or the next 'notch' over it (i.e.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.For instance, a 53.3 kbit/s connection with V.44 can transmit up to 53.3*6 == 320 kbit/s using pure text.^ USB Connection Some Gateways will have a Universal Serial Bus (USB) connection that can be used to connect up to 127 peripheral devices, such as mice, modems, and keyboards.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

^ To be sure, I also added it to a script I added to /etc/ppp/ip-up.d that brought eth1 up if I was using the cable connection (as opposed to my other straight-ppp connection).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ The modem uses DHCP to determine all the settings and connect to the network, so all I have to do it switch on the modem and it automatically dials up and connects to the network.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.However, the compression ratio tends to vary due to noise on the line, or due to the transfer of already-compressed files (ZIP files, JPEG images, MP3 audio, MPEG video).^ A type of analog communications line distortion due to signal variation, and causing data transmission errors.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

[2] .At some points the modem will be sending compressed files at approximately 50 kbit/s, uncompressed files at 160 kbit/s, and pure text at 320 kbit/s, or any value in between.^ Another cause can be an incompatibility between your modem and that at the other end; try turning of Data Compression, dial again.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ At this point, the traffic on the line will most likely be Synchronous, that between the modem and computer will be Asynchronous.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ For example, we can pick 7 bits to be able to send clear ASCII text over a modem.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

[3]
.In such situations a small amount of memory in the modem, a buffer, is used to hold the data while it is being compressed and sent across the phone line, but in order to prevent overflow of the buffer, it sometimes becomes necessary to tell the computer to pause the datastream.^ I explained to her that in order to connect our computer to the phone line, we would need a modem.
  • Computer Stupidities: Modems 18 January 2010 13:44 UTC www.rinkworks.com [Source type: General]

^ Laptop using Cell Phone as Modem .
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ This is necessary for using the BlackBerry as an external modem.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.This is accomplished through hardware flow control using extra lines on the modem–computer connection.^ Always uses V.42 error correction and hardware flow control.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ CCITT, Leased Line for use on leased lines, Modems .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Check the Flow Control - Hardware checkbox.
  • Modem Initialization Strings 18 January 2010 13:44 UTC www.west.net [Source type: Academic]

.The computer is then set to supply the modem at some higher rate, such as 320 kbit/s, and the modem will tell the computer when to start or stop sending data.^ Now, each modem can start accepting digital data from the computer connected to it.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The sending computer will get it and stop sending, waiting for an Xon so it can start sending again.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Some of these modems may even crash your computer if you use them with PhoneSweep.
  • Sandstorm Enterprises® : PhoneSweep® Modem Test Results 18 January 2010 13:44 UTC www.sandstorm.net [Source type: FILTERED WITH BAYES]

Compression by the ISP

.As telephone-based 56k modems began losing popularity, some Internet Service Providers such as Netzero and Juno started using pre-compression to increase the throughput & maintain their customer base.^ Internet Access Controls gives parents or employers the power to decide when users can access the Internet or use Internet applications such as chat and instant messaging, online gaming or all Internet access.
  • ModemSupply.com ~ Best Wholesale Modem Price! 18 January 2010 13:44 UTC dslmodemsupply.com [Source type: General]

^ Modem strings for Netlink If you are having problems connecting to the internet, these are some of the more popular modems and their init strings that seem to work well.
  • Modem strings for Netlink 18 January 2010 13:44 UTC www.getinfo.net [Source type: Academic]

^ This document attempts to explain how to setup some cable modems and internet providers in Linux, the tricks to get them working correctly, and the traps not to fall down.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.As example, the Netscape ISP uses a compression program that squeezes images, text, and other objects at the server, just prior to sending them across the phone line.^ Look at the S switches that set the time you will try to retrain, make sure there is no one picking up the phone on the line you are using.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ TV cable is used for downloading while phone line is used for uploading.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Use the concepts, examples and other content at your own risk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.The server-side compression operates much more efficiently than the on-the-fly compression of V.44-enabled modems.^ On most modems there is more than one AT&F option nowadays.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Ver 6 tests ports, IRQ's, & modem self- connect tests, handshake tests & more than 60 others.
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ What we are already doing though, is sending more than one tone at once; we have one tone for each of the two modems.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Typically website text is compacted to 4% thus increasing effective throughput to approximately 1,300 kbit/s. The accelerator also pre-compresses Flash executables and images to approximately 30% and 12%, respectively.
.The drawback of this approach is a loss in quality, where the graphics become heavily compacted and smeared, but the speed is dramatically improved such that web pages load in less than 5 seconds, and the user can manually choose to view the uncompressed images at any time.^ A: For GPRS BlackBerries such as 7290, speeds go up to about 5 to 5.5 kilobytes per second in good coverage areas.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Some web pages will not load on the BlackBerry itself.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

The ISPs employing this approach advertise it as "surf 5x faster" or simply "accelerated dial-up" [4]

List of dialup speeds

.Note that the values given are maximum values, and actual values may be slower under certain conditions (for example, noisy phone lines).^ Increasing this value sometimes helps on noisy lines..
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ They designed circuitry in the modem that will measure on a phone line how it responds to certain frequencies; some may need to be sent a little louder, some a little less loud.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

[5] For a complete list see the companion article list of device bandwidths. .Please note baud == symbols per second.^ Baud vs. Bits Per Second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The Baud rate on a line indicates how many changes in tones per second there are; for example, on a 300 baud line there are 300 changes per second.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This works pretty good up to about 2400 tones per second or Baud.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Connection Bitrate (kbit/s)
110 baud Bell 101 modem 0.1
300 baud (Bell 103 or V.21) 0.3
1200 Modem (600 baud) (Bell 212A or V.22) 1.2
2400 Modem (600 baud) (V.22bis) 2.4
2400 Modem (1200 baud) (V.26bis) 2.4
4800 Modem (1600 baud) (V.27ter) 4.8
9600 Modem (2400 baud) (V.32) 9.6
14.4k Modem (2400 baud) (V.32bis) 14.4
28.8k Modem (3200 baud) (V.34) 28.8
33.6k Modem (3429 baud) (V.34) 33.6
56k Modem (8000/3429 baud) (V.90) 56.0/33.6
56k Modem (8000/8000 baud) (V.92) 56.0/48.0
Bonding modem (two 56k modems)) (V.92)[6] 112.0/96.0
Hardware compression (variable) (V.90/V.42bis) 56.0-220.0
Hardware compression (variable) (V.92/V.44) 56.0-320.0
Server-side web compression (variable) (Netscape ISP) 100.0-1,000.0

Radio modems

.Direct broadcast satellite, WiFi, and mobile phones all use modems to communicate, as do most other wireless services today.^ Novatel Community support + discussion for all modems from Novatel Wireless, Inc..

^ The rate at which modems communicate over a phone line.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ It is used in most modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Modern telecommunications and data networks also make extensive use of radio modems where long distance data links are required.^ UARTs have an internal clock that they use to make the speed at which serial data flows.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ They supplied me with a D-Link ethernet card (the version of that has changed since then but I believe are still using D-Link) and a Zenith modem.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Such systems are an important part of the PSTN, and are also in common use for high-speed computer network links to outlying areas where fibre is not economical.^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ A network card is provided as part of their large (but currently waived) hookup fee; the D-Link 528CT for PCI capable systems, and, I believe, D-Link 220T for ISA systems (and possibly PCI capable computers that will accept the ISA card, they tried it in my roommate's system first, only when that didn't work did they put in the PCI 528CT).
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Make sure call waiting is disabled, make sure there are no devices such as Fax Machines or Answering Machines or Alarm Systems trying to use the line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Even where a cable is installed, it is often possible to get better performance or make other parts of the system simpler by using radio frequencies and modulation techniques through a cable.^ I haven't used other systems, so I can't judge.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ This includes commercial use, public use, reposting in full/part anywhere on the Internet, publication in magazine/book or any other media, or any other use than private use.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Coaxial cable has a very large bandwidth, however signal attenuation becomes a major problem at high data rates if a digital signal is used.^ Converts an analog signal to digital data.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ However, if you have a way to make this current into a tone, you could make an analog representation of the digital data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.By using a modem, a much larger amount of digital data can be transmitted through a single piece of wire.^ It uses its Digital Signal Processing or DSP chips to try to emulate a modem.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ MODEMCFG.EXE and its data file TELIX.MDM used to set up Telix and your modem for best performance.
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Digital cable television and cable Internet services use radio frequency modems to provide the increasing bandwidth needs of modern households.^ ATT (formerly MediaOne) MediaOne Express is a Internet cable service provided by MediaOne.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ The Cable Modem that was used (provided by Hathway) was a SurfBoard 3100 .
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Replace the DSL modem with a combination modem/router if your broadband service provider allows it.

.Using a modem also allows for frequency-division multiple access to be used, making full-duplex digital communication with many users possible using a single wire.^ The modems themselves used the same protocol on the DCE channel, but this control is usually out of the users' hands.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Wireless modems come in a variety of types, bandwidths, and speeds.^ A technology that enables high-speed modems to operate on poor lines by compensating for the types of lines.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

Wireless modems are often referred to as transparent or smart. .They transmit information that is modulated onto a carrier frequency to allow many simultaneous wireless communication links to work simultaneously on different frequencies.^ The two carriers are on different pitches or Frequencies .
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This technique will allow for every time unit on the line to carry more than just one piece of data, and that is where the difference between Baud and bps comes in.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Transparent modems operate in a manner similar to their phone line modem cousins.^ Well, modem manufacturers did the same with the phone line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ And of course, with more demands on the phone lines, people started looking for ways to better adapt a modem to a phone line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The cable modem connects to an ethernet 10baseT card and a regular phone line.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Typically, they were half duplex, meaning that they could not send and receive data at the same time.^ The process of two modems exchanging information via predetermined signals on how they will send data to one another, such as transmission speed, size of data packets, whether the operation will be full- or half-duplex, etc.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ But to do so, they will need some time and a little data to play with, so they need to be talking to the computer at higher speeds than they are on the line, assuming that they can compress the data and no errors occur.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Typically transparent modems are polled in a round robin manner to collect small amounts of data from scattered locations that do not have easy access to wired infrastructure. .Transparent modems are most commonly used by utility companies for data collection.^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ The modem on either end, and the computer on either end, use UART chips to translate from Synchronous to Asynchronous data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ MODEMCFG.EXE and its data file TELIX.MDM used to set up Telix and your modem for best performance.
  • Telecommunications and Other Modem Programs 18 January 2010 13:44 UTC www.nfbnet.org [Source type: Reference]

.Smart modems come with a media access controller inside which prevents random data from colliding and resends data that is not correctly received.^ However, the receiving modem will need to know when to start listening for data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Data Set Ready, DSR. This signal is controlled by the DCE. It tells the DTE that the Equipment (Modem) is available and functioning to receive data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The two modems will shortly arrive at a mutual conclusion, and now they are ready to start sending and receiving data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Smart modems typically require more bandwidth than transparent modems, and typically achieve higher data rates.^ But to do so, they will need some time and a little data to play with, so they need to be talking to the computer at higher speeds than they are on the line, assuming that they can compress the data and no errors occur.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ On most modems there is more than one AT&F option nowadays.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ What we are already doing though, is sending more than one tone at once; we have one tone for each of the two modems.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

The IEEE 802.11 standard defines a short range modulation scheme that is used on a large scale throughout the world.

WiFi and WiMax

.Wireless data modems are used in the WiFi and WiMax standards, operating at microwave frequencies.^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Dial up Modems using QPSK/QAM. CCITT/ITU standard.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.WiFi is principally used in laptops for Internet connections (wireless access point) and wireless application protocol (WAP).^ You should use the existing Internet connection that is built into the BlackBerry, which is accessed by simply dialing *99# ....
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ You may need to give them a phone call and ask them to add the Access Point Name (APN) to your phone number for Internet access on your cellphone.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Any use of a server type application or service on a computer system connected to 21st Century Cable Modem Service is prohibited and may result in termination of 21st Century Cable Modem Service (i.e.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

Mobile modems and routers

.Modems which use mobile phone lines (GPRS, UMTS, HSPA, EVDO, WiMax, etc.^ The rate at which modems communicate over a phone line.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ CCITT, Leased Line for use on leased lines, Modems .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Look at the S switches that set the time you will try to retrain, make sure there is no one picking up the phone on the line you are using.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

), are known as cellular modems. .Cellular modems can be embedded inside a laptop or appliance, or they can be external to it.^ HOWTO: BlackBerry As Modem For Laptop Introduction Did you know that BlackBerry can now be used just like an external modem for a laptop computer, so that a laptop can have full Internet access?
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ He says they are gertting lots of questions about using the 7290 as a modem for laptops and to date they have no solution.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

External cellular modems are datacards and cellular routers. .The datacard is a PC card or ExpressCard which slides into a PCMCIA/PC card/ExpressCard slot on a computer.^ PCMCIA Interface Control Adapter for PC card modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ You will require a standard 10BaseT ethernet cable to plug the modem into either a network card installed in a PC or the uplink port of a 10BaseT hub.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Standards group for PCMCIA [PC Card] devices.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

The best known brand of cellular modem datacards is the AirCard made by Sierra Wireless.[citation needed] (Many people just refer to all makes and models as AirCards, when in fact this is a trademarked brand name.).December 2009" style="white-space:nowrap;">[citation needed] Nowadays, there are USB cellular modems as well that use a USB port on the laptop instead of a PC card or ExpressCard slot.^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This service provides a dynamic IP address via DHCP. It uses a COM 21 modem plugged in a 10BaseT Ethernet card.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

A cellular router may or may not have an external datacard (AirCard) that slides into it. Most cellular routers do allow such datacards or USB modems. Cellular Routers may not be modems per se, but they contain modems or allow modems to be slid into them. .The difference between a cellular router and a cellular modem is that a cellular router normally allows multiple people to connect to it (since it can route, or support multipoint to multipoint connections), while the modem is made for one connection.^ COM1 Community support + discussion for all modems from the COM One Groupe.

^ This technique will allow for every time unit on the line to carry more than just one piece of data, and that is where the difference between Baud and bps comes in.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ If the line condition has changed since the original connection, retraining the modem will cause it to reconnect at the most efficient speed for the current line condition.

Most of the GSM cellular modems come with an integrated SIM cardholder (i.e., Huawei E220, Sierra 881, etc.) .The CDMA (EVDO) versions do not use SIM cards, but use Electronic Serial Number (ESN) instead.^ They supplied me with a D-Link ethernet card (the version of that has changed since then but I believe are still using D-Link) and a Zenith modem.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ PnP card and installed it in my Mandrake 7.1 (helium) box using the tulip.c driver, version 0.91g.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ If you use CDMA/Verizon/Sprint/Bell Canada: Enter phone number #777 8.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.The cost of using a cellular modem varies from country to country.^ Used in dial up modems and other DCEs using the cellular telephone network .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Some carriers implement flat rate plans for unlimited data transfers.^ For some carriers such as Rogers, the data charges will come out of the same existing BlackBerry plan that is used for email and web browsing.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Other carriers will hit you with extra charges even on an unlimited plan.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Here are the Cingular Unlimited Data Plans: Unlimited on GSM (standard phones) - 19.99 Unlimited on GPRS (blackberry) - 44.99 Unlimited on EDGE (laptop aircards) - 79.99 .
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.Some have caps (or maximum limits) on the amount of data that can be transferred per month.^ Standards that increase the amount of data that can be transferred (data compression) and/or improve the accuracy of transmissions (error correction).
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Generally speaking, on a 14.4k connection, data will transfer at a maximum of 14,400 bps, so maximum throughput is 14,499 bps.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Other countries have plans that charge a fixed rate per data transferred—per megabyte or even kilobyte of data downloaded; this tends to add up quickly in today's content-filled world, which is why many people are pushing for flat data rates.^ The bits per Second rate explains how many bits can go over the line.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Most of the time, downloads range between 1 and 4 kilobytes per second.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ For some carriers such as Rogers, the data charges will come out of the same existing BlackBerry plan that is used for email and web browsing.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.The faster data rates of the newest cellular modem technologies (UMTS, HSPA, EVDO, WiMax) are also considered to be broadband cellular modems and compete with other broadband modems below.^ Cellular Digital Packet Data, a technology for wireless mobile communications.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ So, instead of trying to cram everything into the data stream, we have defined a set of electrical signals that can go to and from the modem and computer to let the other know what is happening.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Eicon Community support + discussion for all Diva and other modems from Eicon Technology Corp..

Broadband

.ADSL modems, a more recent development, are not limited to the telephone's voiceband audio frequencies.^ Modems are no more than an extension to a computer, designed to use ordinary telephone lines to carry digital computer data.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Some ADSL modems use coded orthogonal frequency division modulation (DMT).^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ And on some lines, there may be frequencies that can not be used at all.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The hardware consists of a RealTek ethernet card (just use the rtl8139.o module) and a 3Com U.S. Robotics CMX cable modem.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Cable modems use a range of frequencies originally intended to carry RF television channels.^ The modems themselves used the same protocol on the DCE channel, but this control is usually out of the users' hands.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ For example, on a 300 bps modem connection, there is a 300 baud link, so there are only two sets of frequencies in use.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.Multiple cable modems attached to a single cable can use the same frequency band, using a low-level media access protocol to allow them to work together within the same channel.^ The modems themselves used the same protocol on the DCE channel, but this control is usually out of the users' hands.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ This document attempts to explain how to setup some cable modems and internet providers in Linux, the tricks to get them working correctly, and the traps not to fall down.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Typically, 'up' and 'down' signals are kept separate using frequency division multiple access.^ This is often used to detect whether a connection is Up or Down, so setting this one wrong may cause some real confusion!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.New types of broadband modems are beginning to appear, such as doubleway satellite and power line modems.^ In the Modems tab, you should see a new "Standard Modem" on a new port (such as COM6 or COM11).
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ In the Modems tab, you should see a new Standard Modem on a new port (such as COM6 or COM11).
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ This should also work for others using the same modem, such as Fundy Cable of New Brunswick.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Broadband modems should still be classed as modems, since they use complex waveforms to carry digital data.^ The fastest modems run at 57,600 bps, although they can achieve even higher data transfer rates by compressing the data.

^ In addition, the customers of the service are given(by default, others can be bought, and used) the RCA DCM105 Digital Cable Modem, without utilities disk.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ UARTs have an internal clock that they use to make the speed at which serial data flows.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

.They are more advanced devices than traditional dial-up modems as they are capable of modulating/demodulating hundreds of channels simultaneously.^ Modem comes from MOdulate/DEModulate .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Dial up Modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Then, I talked with the Cingular Data Connect support folks, and they said that the BlackBerry device could not support modem connections (which I ignored) and that the WIX items are not in the billing system anymore.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.Many broadband modems include the functions of a router (with Ethernet and WiFi ports) and other features such as DHCP, NAT and firewall features.^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ One end plugs into the cable modem and the other end into the ethernet card.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Test other software such as Verichat on your BlackBerry to make sure they work, before trying BlackBerry Modem.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

When broadband technology was introduced, networking and routers were unfamiliar to consumers. .However, many people knew what a modem was as most internet access was through dial-up.^ The experience should be similiar to a 56k dial-up modem.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ You should use the existing Internet connection that is built into the BlackBerry, which is accessed by simply dialing *99# ....
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Please look up the APN Settings and then call your carrier and tell them the APN you want added for Internet access on your cellphone.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.Due to this familiarity, companies started selling broadband modems using the familiar term modem rather than vaguer ones like adapter or transceiver.^ On most modems there is more than one AT&F option nowadays.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ What we are already doing though, is sending more than one tone at once; we have one tone for each of the two modems.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ The @Home folks are using Motorola cable modems (I know, I got one) in addition to any other brand folks have reported.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Many broadband modems must be configured in bridge mode before they can use a router.^ Primarily they use DOCSIS 1.1 and up compliant cable modems such as a Terayon LJ110.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ They supplied me with a D-Link ethernet card (the version of that has changed since then but I believe are still using D-Link) and a Zenith modem.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Additional information from Philip Gwyn < gwynp@artware.qc.ca > : They use Motorola CyberSURFR (sic) modems.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

Home networking

.Although the name modem is seldom used in this case, modems are also used for high-speed home networking applications, specially those using existing home wiring.^ The @Home folks are using Motorola cable modems (I know, I got one) in addition to any other brand folks have reported.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Cogeco has now joined the @HOME network although I haven't seen anything good come out of yet.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Notes from Madison, WI and Lakeridge, VA I have a cable modem from Bresnan in madison wi, they use the @home network for internet trafic and supply there users with the RCA cable modems.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.One example is the G.hn standard, developed by ITU-T, which provides a high-speed (up to 1 Gbit/s) Local area network using existing home wiring (power lines, phone lines and coaxial cables).^ TV cable is used for downloading while phone line is used for uploading.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Uses DPSK. CCITT/ITU standard .
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Speeds vary from 19.2 Kbps to the theoretical maximum of 28.8 Kbps for analog dial-up lines.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.G.hn devices use orthogonal frequency-division multiplexing (OFDM) to modulate a digital signal for transmission over the wire.^ It uses its Digital Signal Processing or DSP chips to try to emulate a modem.
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

Deep-space telecommunications

Many modern modems have their origin in deep space telecommunications systems of the 1960s.
Differences with deep space telecom modems vs landline modems
  • digital modulation formats that have high doppler immunity are typically used
  • waveform complexity tends to be low, typically binary phase shift keying
  • error correction varies mission to mission, but is typically much stronger than most landline modems

Voice modem

.Voice modems are regular modems that are capable of recording or playing audio over the telephone line.^ In voice mode, the modem acts like a regular telephone.

^ While the modem interfaces are standardized, a number of different protocols for formatting data to be transmitted over telephone lines exist.

^ We use SurfBoard 1000 ISA board for download and a regular telephone modem for upload.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

They are used for telephony applications. .See Voice modem command set for more details on voice modems.^ Sometimes, it is still tricky to set up a BlackBerry as a modem for a laptop, but this feature is becoming more and more common in cellphones, and BlackBerry models are following suit.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

.This type of modem can be used as FXO card for Private branch exchange systems (compare V.92).^ Alarm systems, fax machines, answering machines and other things that use modems (Such as Credit Card machines!
  • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

^ Where eth0 is the NIC card attached to the cable modem and the 0F4F3E54A659 is the MAC that the cable modem system is expecting.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ This service provides a dynamic IP address via DHCP. It uses a COM 21 modem plugged in a 10BaseT Ethernet card.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

Popularity

.A CEA study in 2006 found that dial-up Internet access is on a notable decline in the U.S. In 2000, dial-up Internet connections accounted for 74% of all U.S. residential Internet connections.^ The modem uses DHCP to determine all the settings and connect to the network, so all I have to do it switch on the modem and it automatically dials up and connects to the network.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Also, my Nortel cable modem does not seem to care which machine or MAC address is connected to it; I have set up multiple machines on it and they all worked fine.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Setting up your Ethernet Card All of the setups below use ethernet cards (network cards) to connect you somehow to the Internet.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.The US demographic pattern for (dial-up modem users per capita) has been more or less mirrored in Canada and Australia for the past 20 years.^ Dial up Modems.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Error correction/data compression standards from Microcom for dial up modems & DCEs using the public switched network.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

^ Dial up Modems using QPSK/QAM. CCITT/ITU standard.
  • Collected Glossary of Modem and Fax Terminology 18 January 2010 13:44 UTC peacetek.net [Source type: Reference]

.Dial-up modem use in the US had dropped to 60% by 2003, and in 2006 stood at 36%.^ Select "Connect using a dial-up modem" then Next.
  • [User] HOWTO: Use BlackBerry As Modem For Laptop! - BlackBerryForums.com : Your Number One BlackBerry Community 18 January 2010 13:44 UTC www.blackberryforums.com [Source type: FILTERED WITH BAYES]

^ Primarily they use DOCSIS 1.1 and up compliant cable modems such as a Terayon LJ110.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

^ Also they should contact me at admin@sunflower.com for lawrence.ks.us domains We use DOCSIS compliant modems now, not the old Zenth stuff.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

.Voiceband modems were once the most popular means of Internet access in the U.S., but with the advent of new ways of accessing the Internet, the traditional 56K modem is losing popularity.^ Modem Init Strings for most popular modems.
  • Modem strings for Netlink 18 January 2010 13:44 UTC www.getinfo.net [Source type: Academic]

^ Modem strings for Netlink If you are having problems connecting to the internet, these are some of the more popular modems and their init strings that seem to work well.
  • Modem strings for Netlink 18 January 2010 13:44 UTC www.getinfo.net [Source type: Academic]

^ In otherwords, when I went to move the cable modem from my NT machine (which was using a proxy server and a second NIC to share internet access) to my new Linux firewall, I had to move the NIC into the new Linux computer.
  • http://www.faqs.org/docs/Linux-HOWTO/Cable-Modem.html 18 January 2010 13:44 UTC www.faqs.org [Source type: General]

See also

References

External links

Standards organizations and modem protocols

General modem info (drivers, chipsets, etc.)

Other

Telephone network modem standards Motorola modem 28k.jpg
Internet access
Network type Wired Wireless
Optical Coaxial cable Twisted pair Phone line Power line Unlicensed terrestrial bands Licensed terrestrial bands Satellite
LAN Ethernet G.hn Ethernet HomePNA  · G.hn G.hn Wi-Fi · Bluetooth · DECT · Wireless USB
WAN PON · Ethernet DOCSIS Ethernet Dial-up · ISDN · DSL BPL Muni Wi-Fi GPRS · iBurst · WiBro/WiMAX · UMTS-TDD, HSPA · EVDO · LTE Satellite

Wiktionary

Up to date as of January 15, 2010

Definition from Wiktionary, a free dictionary

See also modem

Contents

German

Pronunciation

  • IPA: /'modem/

Etymology

.From English modem, abbreviation for modulator demodulator.^ Modem is shorthand for Mod ulator Dem odulator.

^ MO dulate + DEM odulate = MODEM ) .
  • Modem Tutorial - Modem Basics 18 January 2010 13:44 UTC www.azstarnet.com [Source type: Reference]

^ Modems ( mo dulators/ dem odulators) are data communication devices that convert digital signals to analog signals, and vice versa.
  • Modems (Linktionary term) 12 September 2009 15:13 UTC www.linktionary.com [Source type: FILTERED WITH BAYES]

Noun

Modem m., also: n. (plural: Modems)
.
  1. modem; a device that encodes digital computer signals into analog telephone signals and vice-versa.^ Modems ( mo dulators/ dem odulators) are data communication devices that convert digital signals to analog signals, and vice versa.
    • Modems (Linktionary term) 12 September 2009 15:13 UTC www.linktionary.com [Source type: FILTERED WITH BAYES]

    ^ So what a modem does is really this: It reads the computers 'digital' signals, and makes them into tones.
    • Practical Guide to Analog Modems 18 January 2010 13:44 UTC www.myhome.org [Source type: FILTERED WITH BAYES]

    ^ A modem takes computer information and changes it into a signal that can be sent over telephone lines.

    It allows computers to communicate over a phone line.

Simple English

A Modem is a piece of computer hardware. It is used to communicate between distant computers. Two modems, one on each computer, are required to make a connection, and each modem can send and receive data to and from the other modem. The term modem stands for modulator - demodulator.

  • Modulation is changing the digital data in the personal computer to analog data (audio tones or sounds) so that it can be sent.
  • Demodulation is changing the analog data (audio tones) that is received over the telephone lines to digital data to be used by the computer.

Modems are generally classified by the amount of data they can send in a given time, normally measured in bits per second (bit/s, or bps). Pieces of data are sent from one modem to another modem at a set speed or rate. This rate is called the baud rate. One baud is one bit per second.

There are 3 types of modems: internal modems, external modems, and PC card modems. Commonly, modems are used to connect to the Internet through telephone service or cable service. Slow telephone service is called dial-up (maximum 56 kilobaud), faster telephone service is called DSL. DSL data transfer rates are comparable to cable service transfer rates.krc:Модем


Citable sentences

Up to date as of December 24, 2010

Here are sentences from other pages on Modem, which are similar to those in the above article.








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