Here is the glossary of Dial-up definitions from the world of telecommunication.
| ACD (Analog to Digital Converter) | A device that converts an analog waveform to a digital waveform |
| AM (Amplitude Modulation) | A method of storing information in the magnitude of a waveform |
| Bandwidth | The frequency range that extends from the lowest to the highest possible frequencies, a larger bandwidth allows for higher data throughput |
| Bit | A single binary digit |
| bps (Bit per Second) | A measure of data speed |
| BRI (Basic Rate Interface) | A type of ISDN that is sent on 2 or 4 wires and has (2) B-channels at 64Kbps each, and one D-Channels at 16bps |
| CCITT | The International Telephone & Telegraph Consultative Committee is a subsection of the ITU, whose recommendations are followed more closely in Europe than in North America |
| Client Modem | The modem that resides in your home that connects your computer to the analog telephone line |
| CO (Central Office) | The location where the (2) wires (Tip & Ring) from your house are terminated (i.e., connected to electronic equipment) |
| CODEC | COder/DECoder, Converts analog to digital and digital-analog |
| DAA (Data Access Arrangement) | A circuit utilize by the modem to interface the telephone line to the CODEC |
| DAC ( Digital to Analog Converter) | A device that converts a digital waveform to an analog waveform |
| dB (Decibel) | Unit and Scale used for measuring the amplitude of one signal to another signal, dB = 10*Log(P1/P2) |
| Digital Pad | An attenuator that comes most commonly in 3dB and 6dB values, used in the network to reduce amplitudes, these pads negatively affect V.90 |
| DP (Dial Pulse) | Pulses that a rotary telephone generates in making a call |
| DSP (Digital Signal Processor) | A Micro Processor that is dedicated to calculating the complex mathematics to process digital waveforms |
| DTMF | Dual Tone Multi-Frequency is the technique by using two simultaneous tones to represent digits – Touch Tone |
| E1 | A (4) wire European Telco Standard that carries data at 2.048 Mbps |
| EMI | Electromagnetic Interface |
| FCC | USA Federal Communication Commission |
| Harmonic Distortions | Due to non-linearity’s in the communication channel that produces harmonics (integer multiples) of the original signal |
| Hybrid | A circuit that makes the transformation from a 2 wire transmission to a 4 wire and also the reverse |
| Hz (Hertz) | The measure of frequency, Cycles per Second |
| ISDN (Integrated Service Digital Network) | Telephone service that is based on two digital channels |
| ISP (Internet Service Provider) | The organization that connects individuals to the World Wide Web (www) |
| ITU | International Telecommunications Union; the standards agency that set the V90 modem standard in Geneva on Feb 6, 1998 |
| K56flex | An open 56K standard developed by Rockwell and Lucent that is being eclipsed by V.90 |
| Kbps (Thousand Bit per Second) | A measure of data speed |
| KHz (Kilo-Hertz) | Thousand Cycles per Second |
| LAN | Local Area Network |
| Local Loop | The analog telephone line that runs from your house to your local CO |
| MAC | Media Access Controller |
| Mbps (Million Bit per Second) | A measure of data speed |
| MHz (Mega-Hertz) | Million Cycles per Second |
| Modem | MOdulate/DEModulate, Interface device between the telephone line and the local computer |
| Multiplexer | A device that integrates serial digital waveforms into a single channel by partitioning the inputted data into segments and combining them together into a bitstream |
| PBX (Private Branch Exchange) | Private Telephone system that many companies use for their internal telephone service |
| PCM (Pulse Coded Modulation) | A digital waveform that stores data in a modulated pulse, this technique is used by V.90 |
| Port | An interface on a computer that is used to connect a peripheral device such as a modem |
| POTS | Plain Old Telephone Service, analog telephone line |
| PRI | Primary Rate Access of 23 B-channels (64Kbps each) with 1D-Channel (16Kbps) that operates at T1 data rates |
| PSTN | Public Service Telephone Network |
| Quantization | The process that ADC use to convert Analog to Digital |
| Quantization Error | The error that occurs when an analog waveform that can be any value in an infinite range is converted to a digital value that is at finite discrete levels |
| Ring | One of the wires that make up the local loop, Ring, is the connected Ring on the jack used when operators use to switch the calls. Also, the term for the energy on a POTS line that allows the telephone to ring |
| RJ-11 | Telephone connector used in the USA for connecting to Tip and Ring |
| Robbed Bit Signaling | An older technique used by the telephone companies on T1 lines that use digital transmission. The technique takes the least significant bit to control functions such as a Dial Tone, Ring, Busy Answer, etc. This signaling method negatively affects V.90 by reducing the data rate. |
| Server Modem | The modem that resides at the remote server and is usually connected to digital lines |
| Shannon’s Theorem | Defines the relationship between the maximum throughput in any given channel to the presence of noise |
| SNR (Signal to Noise Ratio) | A measurement of Signal Power divided by the Noise Power, measured in dB’s |
| Symbol | It is a representation of a group of bits into a signal waveform |
| T1 | A (4) wire USA Telco Standard that carries data at 1.544 Mbps |
| Telco | Telephone Company |
| Tip | One of the wires that makes up the local loop, Tip, is the end of the jack that was used when operators use to switch the calls |
| V.80 | A synchronous connection between a modem and PC to allow the PC to adjust the flow of video data during a point to point H.324 video call |
| V.90 | The international 56K analog modem standard |
| V.PCM | A pre-standard reference to Pulse Coded Modulation used as a working name before V.90 was named |
| WAN (Wide Area Network) | The POTS, ISDN, T1, and ext. that are used to connect to distance locations |
| X2 | A proprietary USR/3-Com Standard that is being eclipsed by V.90 |
| XDSL | Digital Subscriber Line where the “X” denotes for the many forms of the technology, XDSL is an asymmetric transmission that is capable of data transfers theoretically of up to 52 Mbps |
