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Telecom Glossary

1...9 A B C D E F G H I J K L M N O P Q R S T U V W X Z

1�9

2G
Most common type of wireless telephone communication today. It allows slow data communication, but its primary focus is voice.

2.5G
Bridging standard between 2G and 3G. Digital communication allows email and simple Web browsing.

3G
3G stands for the third generation of wireless communication technology. It refers to pending improvements in wireless data and voice communications through any of a variety of proposed standards. The immediate goal is to raise transmission speeds to 2Mbit/sec.

802.11
A group of wireless specifications developed by the IEEE. It give details of a wireless interface between devices to manage packet traffic (to avoid collisions, etc.).

A	Top
A-bis Interface between the BSC and BTS in a GSM network.
A-interface Interface between the MSC and BSS in a GSM network.
Access point A WLAN transceiver or "base station" that can connect a network to one or many wireless devices. AP�s can also bridge to one another.
Access Service Access services are specified sets of information transfer capabilities furnished to users at telecommunications network points-of-termination (POTs) to provide access to network transport services. Two examples are the following: subscriber access lines, the connection between a network POT (in this case more commonly known as a Network Interface NI) and a local exchange carrier switching system; and trunks between interexchange carrier points of presence and local exchange carrier switching systems (The POT at the POP is identified as the point ofinterface POI). End to end connections require originating and terminating access services .
Access Tandem (AT) AT is a LEC switching system that performs concentration and distribution functions for inter LATA traffic originating or terminating within a LATA.
Acoustic Coupler This is a special cradle in which you place the handset of a phone. This is connected to a modem, and the modem accesses the phone line through this coupler. Modern modems connect directly to the phone line.
Adapter A device that enables something to be used in a different way from which is was intended, or makes different pieces of equipment compatible.
Address Signals Address Signals convey destination information such as a called 4-digit extension number, central office code, and when required, area code and serving IXC carrier code. These signals may be generated by station equipment, or by a switching system.
Advanced Services With ongoing advancements in telecommunications, always-on, ubiquitous multimedia services have become a focus for both users and service providers. Now, high-speed broadband connectivity for the delivery of voice, video, and data is the demand of the hour. Services such as Video on Demand, IPTV, Stream Mobile Video, and advanced gaming are what the user now expects of the service provider.
Asymmetric Digital Subscriber Line (ADSL) Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional modem can provide. It does this by utilizing frequencies that are normally not used by a voice telephone call, in particular, frequencies higher than normal human hearing. This signal will not travel very far over normal telephone cables, so ADSL can only be used over short distances, typically less than 2 km. Once the signal reaches the telephone company's local office, the ADSL signal is stripped off and immediately routed onto a conventional internet network, while any voice-frequency signal is switched into the conventional phone network. This allows a single telephone connection to be used for both ADSL and voice calls at the same time.
Analogue Analogue refers to signals that can represent an infinite range of numbers, as opposed to digital which can only be distinct whole numbers. Analogue data often comes from measurements, like a sine wave. The sound a modem makes over the phone is analog since it can be any of a number of different frequencies. The fixed-line networks usually transfer analogue data and fax. The GSM networks are Digital.
Automatic Number Identification A service feature in which the directory number or equipment number of a calling station is automatically obtained. The code that provides the billing number of the line or trunk that originated a call. 3. A system that identifies the billing account for a call. For 911 systems, the ANI identifies the calling party and may be used as a call back number.
Analog Carrier System An analog carrier system is a transmission system that uses repeaters that compensate for analog medium impairments, and produce output signals that are linear scaled versions of input signals. Analog carrier systems can carry speech, data, video and supervisory signals although they are best suited for speech signals.
Analog Signal An analog signal is a continuous electrical signal that varies in direct correlation with an impressed phenomenon, stimulus, or event that bears intelligence. Sound waves and their electrical analogs are characterized by loudness (amplitude) and pitch. Analog signals can assume any of an infinite number of amplitude values or states within a specified range, in accordance with or analogous to, an impressed stimulus. Pitch refers to how many times per second the signal swings between high and low amplitudes, i.e., its frequency.
ANSI ANSI graphics is a set of cursor control codes which originated on the VT100 smart terminal. Many BBS's use these codes to help improve the sending of characters to communications programs. It uses the escape character, followed by other characters, which allow movement of the cursor on the screen, a change of color, and more.
Archie A program and database which locates files on the Internet.
ARPANET Advanced research projects agency and Network. An early experimental network.
ASCII American Standard Code of Information Interchange. It uses 7 bits to represent all uppercase and lowercase characters, as well as numbers, punctuation marks, and other characters. ASCII often uses 8 bits in the form of bytes and ignores the first bit.
ASB Asynchronous balanced mode.
ASI Alternate space inversion.
ASCII transfer When a text file is sent directly as it is, without any special codes.
Asynchronous Transfer Mode (ATM) ATM is a broad-bandwidth, low delay, packet-like (cell relay) switching and multiplexing technique. It is essentially connection oriented, although it is envisioned to support all services. ATM networks will accept or reject connections based on user's average and peak bandwidth requirements providing flexible and efficient service for LAN-to-LAN, compressed video and other applications that involve variable bit rate (VBR) traffic.
Asynchronous Transmission Transmission method in which the intervals between transmitted characters may be unequal of length. Transmission is controlled by start and stop bits at the beginning and end of each character. This way, if there is line noise, the modem can find out right away where the next byte should start.
AT Command Any instructions sent to a modem that begin with "AT". See also Hayes AT command set.
Attention characters The letters "AT", which get the modem's attention that you are about to send it a command.
Automatic Call Distribution (ACD) ACD is a means for efficiently directing and managing large numbers of incoming calls to specific departments/terminals within an organization.
Auto Reliable The ability of a modem to be able to communicate both with modems that do have error-control and/or data compression, and those that do not.

B	Top
Backbone Network A backbone network is a transmission facility designed to interconnect often lower-speed distribution networks, channels, or clusters of dispersed terminals or devices.
Backbone wiring In a premises distribution system, backbone wiring is the cable connecting telecommunications closets and equipment rooms within a building, and/or between buildings in a campus. Backbone wiring is sometimes referred to as the riser subsystem.
Bandwidth The difference between the upper and lower limits of a band. A range of radio, audio, or other frequencies. Since it is so limited, a modem must carefully change data into sounds that "fit" within this range. Similar to frequency spectrum. Bandwidth of a voice channel is 3000Hz-300Hz which equals 2700Hz. Telephone lines have a bandwidth from 300 hertz to 3400 hertz.
BASIC Beginners All purpose Symbolic Instruction Code. It is a programming language. It is called symbolic because it allows programmers to use symbols to represent numbers and information. In algebra, these symbols are called variables.
Balun Balanced/Unbalanced. A device which connects a balanced (two wire) line, such as a phone line, to an unbalanced (coaxial) line, like cable. The two wire line is called balanced because the currents in each wire are equal and in opposite directions.
Baud A term referring to the speed at which modems communicate. Technically, it is the number of changes in an electronic signal per second. Since the number of changes used to be the same as the number of bits sent or received per second, bps and baud are often used interchangeably. However, there is a difference, which is very often confused. For example, many 1200bps modems were advertised as 1200 baud, even though they operate at 600 baud. They send out 2 bits 600 times a second, which means that it is 600 baud. However, since it is so often misunderstood, you can assume that when you see "baud" it means bits per second, unless it is stated otherwise.
BFT Binary File Transfer.
Billion Rand What it costs to start a cellular network.
Binding Post A binding post is a screw with a small nut mounted on a terminal box. Wires are joined together by wrapping them around a screw and then tightening the nut on them.
Bipolar Signals Bipolar signals are signals in which positive and negative pulses, always alternating, represent one binary signal state only. The absence of pulses represents the other binary state. Bipolar has two forms, AMI and ASI. In alternate mark inversion (AMI) the pulses correspond to ls; in alternate space inversion (ASI) the pulses correspond to 0s.
BIPS Billion Instructions per second
BISDN Broadband Integrated Services Digital Network
Bit A Binary Digit. It is a number in base 2 (binary), which means that it can only be a 0 or a 1. It is used in the expression `bits per second'.
Bit Error (BER) BER is the ratio of the number of bits received with errors to the total number of bits transmitted. BER and the average number of error-free seconds are the principal impairment measurements for digital channels.
Bit Rate Bit rate is the capacity characteristic of digital signals as defined by the number of bits (or bytes) per second that a channel will support. For example, a transmission facility that can support information exchange at the rate of I megabit per second (1 Mbps or 1,000,000 bits per second) delivers the same quantity of information, i.e., throughput, as a 1 kilobit per second (kbps or 1,000 bits per second) facility, but, in only 1/1000 of the time.
Bps Bits Per Second. The transmission speed of most modems is measured in baud or bps. Bps is literally the number of bits sent by the modem every second.
Blackberry Blackberry is the one-stop, no-compromise, wireless solution that allows you to stay connected with wireless access to email, phone, web and organizer features. Blackberry� offers leading wireless solutions, providing access to a wide range of applications
Block size When used with either error control or data compression protocols, refers to the number of characters to be sent at one time. If error control is used, the codes are sent immediately following this block. Typical block sizes are 64, 128, 192, or 256 characters. Small block sizes are better when the line quality is bad (such as for long distance calls), while large block sizes are better during good connections (such as for local calls).
Blocking or Blockage A condition where congestion within a radio communications system or network is so great, due to excess demand from users, that new calls cannot be completed without delay. A "busy signal".
Bluetooth A low power, short range wireless technology designed to provide a replacement for the serial cable. Operating in the 2.4GHz ISM band, Bluetooth can connect a wide range of personal, professional and domestic devices such as laptop computers and mobile phones together wirelessly.
BSC Base Station Controller, the network entity controlling a number of Base Transceiver Stations.
BSS Base Station System/Subsystem.
BTS Base Transceiver Station, the network entity which communicates with the mobile station.
Bridge Tap Bridge tap is an undetermined length of wire attached between the normal endpoints of a circuit that introduces unwanted impedance imbalances for data transmission.
Bridges In IEEE 802 local area network (LAN) standards, bridges are devices that connect LANs, or LAN segments, at the data link layer. Bridges provide the means to extend the LAN environment in physical extent, number of stations, performance and reliability. Bridges perform three basic functions: frame (as opposed to packet) forwarding; learning of station addresses; and resolving of possible loops in the topology by participating in the spanning tree algorithm. Self learning bridges construct tables of network addresses by listening" to source address information contained in data signal frames. Other functions include the ability to filter traffic to keep traffic originating and terminating in one network segment from leaving that segment; restricting specified traffic to one segment that might otherwise be routed to other segments; and collecting and storing network management and control information obtained via traffic monitoring.
Broadband The use of cable to provide data transfer using analog (radio-frequency) signals. Digital signals must be passed through a modem and transmitted over one of the frequency bands of the cable. Multiple channels carry data on a single physical cable. Cable TV is an example of broadband transmission. The term is commonly associated with high speed data transfer connections.
Broadband Integrated Services Digital Network (BISDN) CCITT is developing a BISDN umbrella standard, incorporating underlying standards for integrated digital network switching, multiplexing and transmission facilities, that will be able to meet expanding voice, data, video and other requirements well into the future. In one of the first draft CCITT documents BISDN is simply defined as "a service requiring transmission channels capable of supporting rates greater than the primary rate". In the U.S. the primary rate for "narrowband" ISDN (as the current standard is sometimes referred to) is 1.544 Mbps.
Brouters Brouters are devices that combine the functions of bridges and routers.
Buffer Box A device that temporarily stores data, usually between two devices with different data speeds; sends data out at a speed that the slower machine can handle. Recommended to prevent CDR loss on a call accounting system.
Bus In digital systems, e.g., time division multiplexing equipment, a bus (also referred to as a highway) is defined as one or more conductors (or some medium) that connect a related group of devices.
Business Applications Business applications are unique aggregations of telecommunications services that satisfy particular enterprise needs.
Byte A group of 8 bits. It usually represents one character

C	Top
CAB Carrier Access Business.
Call barring A service which enables users to bar certain incoming or outgoing calls on their mobile phones.
Call timer A service which keeps track of the amount of airtime being used by the subscriber on a cumulative basis
Call divert The capability to divert incoming calls to another phone (fixed or mobile) or to an answering service.
Call hold The ability to put an ongoing call on hold whilst answering or making a second call
Caller ID Caller Identification; displays the name/number of the person calling a mobile phone. Also known as CLI.
CAMEL Customized Application for Mobile network Enhanced Logic is an IN feature in GSM networks that enables users to carry personal services with them when roaming into other networks that support CAMEL.
CCITT Consultative Committee International on Telephones and Telegraphy. Used to set standards for modems. Replaced by the ITU.
Call Accounting System A computer, a magnetic storage device (floppy or hard disk), software and some mechanical method of attaching itself to a telephone system. A call accounting system is used to record information about telephone calls, organize that information and prepare reports - printed or to disk. The information it captures about phone calls typically includes from which extension the call is coming, which number it is calling (local or long distance), which circuit is used for the call (WATs, MCI, etc), when the call started, how long it lasted, for what purpose the call was made (client or project, etc). A call accounting system may also include information on incoming calls - which trunk was used, where the call came from, which extension took the call, if it was transferred and to where and how long it took.
Capacity Based The capacity-based interconnection regime implies that network resources, sufficient for satisfying interconnection requirements, are allocated to a competing operator under a contracted capacity (or number of links) to route eligible traffic. The competing operator is then billed a fixed amount for the contracted links independently of the number of minutes exchanged between the two networks. The capacity-based model can be applied to voice traffic, narrow-band internet access (dial-up), broadband networks, as well as IP dial-up access.
Card Services DOS and Windows 3.1x users must have Card Services enabled to use their computer's PCMCIA slot(s). Card Services simply allows DOS/Windows 3.1 to see and set up the computer's PCMCIA slot. They will automatically allocate a Communications Port (COM 1 to 5) when the Option modem is plugged in. The Option modem can then be accessed by communications programs via the Windows 95-assigned COM port. Windows 95 users do not need to install Card Service as it is built into Windows 95. Notebook users using DOS/Windows 3.1 usually have the Card Services software bundled with their purchase. Option modems come packaged with a PC Card Installation disk that has an install program for these Card Services.
Carrier Detect The information as to whether or not the modem senses a carrier, like a fixed-line dialing tone or a data/fax services enabled on a GSM subscription.
CIS Card Information Services. A PCMCIA setup protocol.
Carrier Detect Threshold A way of measuring how well a modem can detect valid data over noisy phone lines. It is measured in negative dBm's (decibel-milliwatts). The bigger the number (the more negative) the better. For example,45 dBm is better than 40 dBm.
CLIP Caller Line ID Presentation. A code that is sent over the phone lines in some areas when a person makes a phone call. This code includes the phone number of the person making the call. Some modems are able to understand this signal, and let you know who is calling you before you answer the phone.
CLIR Caller Line ID Restriction. The ability to block someone who you're calling from seeing your number.
CDPR Cellular Digital Packet Radio
CDR Call data generated by the PBX in the form of an ASCII file that includes records of outgoing and incoming calls, who made or received the calls, incoming and outgoing locations of the calls, call length, time call took place and other information.
Cell The receiver/transmitter a GSM phone connects to the equivalent of the base station of a cordless phone. A cell can support a number of simultaneous calls.
Centrex A telephone business service provided by a local phone company from a local central office and provides features directly to each phone at a business without using an on-site PBX
Checksum A number that represents a larger group of numbers in order to check for errors in data transmission. It is commonly used when downloading a program, as well as in error control protocols. The checksum is the result of a mathematical equation, such as adding all the numbers in a block together (although it is usually more complex than that).
Chip Set A group of important IC chips on a modem (or other computer peripheral) that are all made by the same manufacturer. While there are many companies that make modems, there are only a few that make the chips for them. Because the chip manufacturer is making the chips for many companies, they produce more chips, and the price of the chips is lower than if each company produced their own. This decreases the price of the modems on the market.
CDMA Code Divison Multiple Access. A digital cellular technique invented by Qualcomm.
CLEC Competitive (or Certified) Local Exchange Carrier - the Telecommunications Act of 1996 opened the door for smaller companies to compete with the ILEC (Incumbent LECs), such as RBOCs (Regional BOCs) for local, long distance, international, internet and entertainment (see BOC, LEC).
Client/Server A network architecture that lets a user at a PC request information or applications from another computer over a LAN (see LAN).
CMOS Complementary Metal Oxide Semiconductor, A chip which uses small amounts of electricity. It is used typically on battery-powered computers and to save configuration information on other computers when they are turned off.
Communications program A program that controls a modem, and has features that allow the user to do such things as upload, download, etc. It is similar to a terminal program but more sophisticated. An example is Trumpet WinSock for connecting to the Internet, and Windows HyperTerminal
Compatible When one object can work just like another. Although the term is usually used with computers, it is often used with modems. Many modems are compatible with other popular modems.
Compress To make data take up less space. Archiving programs do this, which means that files will take less time to transfer with modems. Many modems now have the ability to automatically compress the information they send and receive. [See also archive, data compression].
Comport Communications port, also known as a serial port (see Serial Port).
CODEC Compressor/DECompressor, the chip inside every digital GSM cellphone that allows the cellphone to tranmsit voice data at high efficiency and speed across the GSM cellular network. The CODEC will trip redundant voice data like when neither party is talking allowing more efficient use of scarse bandwidth.
Code division multiple access (CDMA) A coding scheme, used as a modulation technique, in which multiple channels are independently coded for transmission over a single wideband channel. Note 1: In some communication systems, CDMA is used as an access method that permits carriers from different stations to use the same transmission equipment by using a wider bandwidth than the individual carriers. On reception, each carrier can be distinguished from the others by means of a specific modulation code, thereby allowing for the reception of signals that were originally overlapping in frequency and time. Thus, several transmissions can occur simultaneously within the same bandwidth, with the mutual interference reduced by the degree of orthogonality of the unique codes used in each transmission.
Customer Management Managing customers over a long run is a challenge that business fight continuously. Customer management requires the development of methodologies, service packages, and understanding of customer needs-especially with regard to service offerings, and efficient and accurate billing-to encourage loyal customer support and retention.
Customer Premises Equipment (CPE) Terminating equipment (such as terminals, telephones, and modems) supplied by the telephone company, installed at customer sites and connected to the telephone company network. Can also refer to any telephone equipment residing on a customer site.
CEPT Conference of European Post and Telecommunications, the European telecommunications authority.
Cracker From hacker and safe cracker. A hacker who breaks into computers
CTS Clear To Send, This is when the modem lets the other computer know that it can send information to the other computer. [See also Flow Control, Return To Send].
CTS/RTS The method of flow control that uses the CTS and RTS signals. It is built into the hardware, not software.

D	Top
DAA Data Access Arrangement, A device used to connect modems to the switched telephone network.
Data over GSM Send digital data over the digital GSM networks.
DCE Data Circuit Terminating Equipment, Sets up and maintains a data connection link over a communications medium. For example, a modem.
Data Compression Some modems have the capability to 'squash' data so that it takes up less space. When another modem (that also has this capability) receives the data, it 'unsquashes' the data to its original form. By using data compression, a modem can send information faster. It's a lot like shorthand--all the information is still there, but it takes less space and is quicker.
Data Transmission rate The speed at which data travels. For example, data may be sent at 115,200bps. Same as transmission rate, transmission speed, data rate.
DB Loss Decibel (dB) is a unit of measure of signal strength, usually the relationship between a transmitted signal and a standard signal source. Loss is measured when the signal received across a communication circuit is less than what was transmitted by the signal generator.
DBM Decibel refers to one milliwatt. This is used to measure certain levels, such as transmit level.
DSA Data Services Adapter, an alternative interface to PCMCIA for connecting to a fax or data terminal. The Siemens S1 uses a DSA.
Digital A system using discrete numbers to represent data. In computer systems, these are the numbers 0 and 1 (for binary). [See also Analogue].
Digital Carrier Systems Digital Carrier Systems are carrier systems for digital signals that uses regenerative versus linear repeaters and time division multiplexing.
Digital Divide The digital divide is the gap between those with regular, effective access to digital technologies and those without.
Dispersion In dispersive media, dispersion are complex signals are distorted because the various frequency components which make up the signal have different propagation characteristics and paths. Due to the finite conductivity of copper, wire or cable media for guided wave transmission is fundamentally dispersive. Dispersion limits the upper bit rate that a medium can support by distorting the signal waveforms to the extent that transitions from one information state to another cannot be reliably detected by receiving equipment, (e.g., logical l logical 0 value changes).
DSP Digital signal processor.
DSR Data Set Ready, This indicates that the modem is on, and ready to accept input from the computer (either commands or data to be sent over the phone line)
DSL (Digital Subscriber Line), A family of technologies generically referred to as DSL or xDSL that are capable of transforming a normal telephone line into a high-speed digital line. These include ADSL (Asymmetric DSL), SDSL (Symmetric DSL), HDSL (High data rate DSL) and VDSL (Very high data rate DSL). DSL enabled lines are capable of supporting services such as fast Internet access and video or TV on-demand.
DTE Data Terminal Equipment. This is computer equipment which is not directly responsible for communicating, for example, the computer itself and printers. [See also DCE].
DTMF Dual Tone Multi-Frequency. This is used in tone dialing. It is a method where 2 distinct tones are sent for each digit dialed.
DTR Data Terminal Ready. The DTR signal is sent from the computer to the modem, to let the modem know that the computer is ready to communicate.
Dual Band The capability of GSM infrastructure elements and handsets to work across both the 900MHz and 1800MHz bands. The capability to seamlessly handover between the two bands offers operators major capacity gains.

E	Top
E1 Link A wide area digital transmission scheme used predominantly in Europe that carries data at a rate of 2.048Mbps.
EDGE Enhanced Data rates for GSM Evolution; effectively the final stage in the evolution of the GSM standard, EDGE uses a new modulation schema to enable theoretical data speeds of up to 384kbit/s within the existing GSM spectrum. An alternative upgrade path towards 3G services for operators, such as those in the USA, without access to new spectrum. Also known as Enhanced GPRS (E-GPRS)
EDI Electronic Data Interchange. Commonly transferred by Internet or X.400 networks
EEPROM Electrically Erasable Programmable Read-Only Memory
EFF Electronic Frontier Foundation. An organization promoting civil rights in cyberspace. It is leading the fight against the US government's Clipper Chip.
EGSM Extended GSM is an extension of the original 900 GSM frequency range to make more spectrum accessible in the European countries, but which is also supported in other countries excluding the US and Canada. Handsets designed after 2001 automatically support this extended spectrum. ESGSM is also known as EGSM900.
EIR The EIR (Equipment Identity Register) is often integrated to the HLR. The EIR keeps a list of mobile phones (identified by their IMEI) which are to be banned from the network or monitored.This is designed to allow tracking of stolen mobile phones. In theory all data about all stolen mobile phones should be distributed to all EIRs in the world through a Central EIR. It is clear, however, that there are some countries where this is not in operation. The EIR data does not have to change in real time, which means that this function can be less distributed than the function of the HLR.
Enabling policies Any set of governmental initiatives, efforts, and policies that facilitate the expansion of ICT infrastructure in the country, allow healthy competition to thrive, and provide connectivity to disconnected areas to encourage economic growth.
Encryption The process of scrambling a message, such as a digital phone signal, to prevent it from being read by unauthorized parties
Erlang An erlang is an international dimensions unit of the average traffic intensity of a facility during a period of time; one erlang of traffic is equivalent to a single user who uses a single resource 100% of the time. See centicall seconds.
Error Correction Error Correction. The ability of a modem to notice errors in transmission, and to resend incorrect data.
ETSI European Telecommunications Standards Institute.
Ethernet A standard protocol (IEEE 802.3) for a 10-Mb/s baseband local area network (LAN) bs using carrier-sense multiple access with collision detection (CSMA/CD) as the access method, implemented at the Physical Layer in the ISO Open Systems Interconnection--Reference Model, establishing the physical characteristics of a CSMA/CD network.
ECFP European Conference on Computers, Freedom, and Privacy.
Email Electronic mail. Messages that are sent to individual people. You choose who to send the message to and only that person receives the message.
ESPRIT European Strategic Program for Research in Information Technologies.
Error When there is line noise and one or more characters are changed. This is especially noticeable when downloading or uploading a program. In this case the error must be detected, and the data must be re-sent.
Exchange Carrier (or local exchange carrier LEC) An exchange carrier is any company, BOC or independent which provides intra-LATA telecommunications within its franchised area.
Extranet One-to-one connections over the Internet that are not accessible to all; mainly set up by a business for their customers or business partners.

F	Top
FAQ Frequently Asked Questions.
FTTH Fiber to the Premises (FTTP) or Fiber to the Home (FTTH) is a broadband telecommunications system based on fiber-optic cables and associated optical electronics for delivery of multiple advanced services such as the triple play of telephone, broadband Internet and television all the way to the home or business. In the near future, FTTP, also referred to as Extreme Broadband, will deliver performance speeds exceeding 100 Mbps downstream. In contrast, Fiber to the Node/Neighborhood (FTTN) stops short of delivering and physically attaching a fiber optic cable directly to the home or business, therefore, is not classified as Extreme Broadband.
Firewall Computer security that attempts to keep crackers out.
Flame To write emotional remarks on electronic mail.
Flow control A method of controlling when information is sent. One method is Xon/Xoff, where a BBS will send information until your computer sends an Xoff (CTRL-S). It will resume sending information when you send an Xon.
FMC Fixed-Mobile Convergence is marked by at least three distinct areas of convergence: Network Convergence, Device Convergence, and Marketing Convergence. In Network Convergence, all convergence is invisible to the end-user and happens at the networks and systems level. This essentially means that all network applications and activities run on a standard language for network communication-that is, Internet Protocol (IP). In Device Convergence, "everything", theoretically, gets placed inside one device, which supports WiFi as well as cellular functionalities, supports email services along with email attachments, can serve as a desk phone, replaces digital camera, and so on and so forth. The only condition for the adoption of a successfully "converged" device would be its user-friendliness and intuitive design. In Marketing Convergence, companies market both devices and communications services to allow users to buy both from the same vendor on the same bill. This "bundling" allows users and enterprises to benefit (arguably) from lowered total prices.
Frame In time division multiplexing systems, Frame is a sequence of time slots each containing a sample from one of the channels carried by the system. The frame is repeated at regular intervals, (normally the sampling rate used in analog-to-digital conversion processes for signals being multiplexed) and each channel usually occupies the same sequence position in successive frames.
Frame Relay Frame relay is a network interface protocol defined in CCITT Recommendation 1.122 "Framework for additional packet mode bearer services," as a packet mode service. In effect it combines the statistical multiplexing and port sharing of X.25 packet switching with the high speed and low delay of time division multiplexing and circuit switching. Unlike X.25, frame relay implements no layer 3 protocols and only the so-called core layer 2 functions. It is a high-speed switching technology that achieves ten times the packet throughput of existing X.25 networks by eliminating two-thirds of the X.25 protocol complexity The basic units of information transferred are variable length frames, using only two bytes for header information. Delay for frame relay is lower than for X.25, but it is variable and larger than that experienced in circuit switched networks. This means that currently frame relay is not suitable for voice and video applications where excessive and variable delays are unacceptable.
Frequency Frequency is acoustic waves and electrical signals might be made up of only a single tone, like a single note on a piano. In this case the signal waveform is made up of repeating identical "cycles" and is said to be of a single frequency, equal to the number of cycles that occur in one second of time. In communications, frequency was traditionally expressed in cycles per second, but is now expressed in hertz (Hz), still equal to one cycle per second. Thus, one thousand cycles per second is equal to one thousand hertz, or a kilohertz (kHz).
Frequency Division Multiplexing (FDM) FDM divides the frequency bandwidth (spectrum) of a broadband transmission circuit into many subbands, each capable of supporting a single, full time communications channel on a non-interfering basis with other multiplexed channels. FDM multiplexing is generally suitable for use with analog carrier transmission systems.
Frequency Reuse The use of many low-elevation antenna and/or low-power sites, so that the same frequencies can be reused in numerous sites separated by a defined distance without causing interference. Thus frequencies re-use systems can increase capacity and reuse frequencies more often.
Full Duplex A channel providing simultaneous transmission in both directions.
Fully Dedicated Access Long distance carrier access method in which a non-local call is carried by the long distance carrier via a dedicated trunk facility for both the first and last part of the call's journey, and on the same long distance carrier's network for the entire length of the call. Also referred to as "dedicated-to-dedicated" or "on-net to on-net."

G	Top
Gateway Entrance/exit to a communications network; electronic repeater device that intercepts and guides electrical signals from one network to another; filters out unwanted noise.
Geographic Portability The ability of customers to transfer their numbers between operators on fixed telecommunications networks when they switch their operator.
GMSK The method of modulation used by GSM is Gaussian Minimum Shift Keying (GMSK), with a BT value of 0.3 at a gross data rate of 270 kb/s.
Grey Traffic Illegal telecom traffic
Group III FAX The standard controlling fax communication.
GSM GSM originally stood for Groupe Speciale Mobile but has been anglicised to Global System for Mobile Communications, an international digital cellular standard. South Africa was one of the first to implement Phase 2 of GSM.
GPRS General Packet Radio Service, standardised as part of GSM Phase 2+, GPRS represents the first implementation of packet switching within GSM, which is a circuit switched technology. GPRS offers theoretical data speeds of up to 115kbit/s using multislot techniques. GPRS is an essential precursor for 3G as it introduces the packet switched core required for UMTS
GPS Abbreviation for global positioning system. A satellite-based global navigation system that consists of (a) a constellation of 24 satellites in orbit 11,000 nmi above the Earth, (b) several on-station (i.e., in-orbit) spares, and (c) a ground-based control segment. The satellites transmit signals that are used for extremely accurate three-dimensional (latitude, longitude, and elevation) global navigation (position determination), and for the dissemination of precise time. GPS-derived position determination is based on the arrival times, at an appropriate receiver, of precisely timed signals from the satellites that are above the user's radio horizon.
GUI Graphical User Interface - a computer user interface that uses graphical representation instead of characters; makes the interface easier and more intuitive to use. i.e. Windows 95.
Guided Media Guided media is media that constrain electromagnetic or acoustic waves within boundaries established by their physical construction. Examples include paired metallic wire cable, coaxial cable, and fiber optic cable.

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H.323 One of two main standards regarding voice transmissions over data networks, the other main standard is VoFR.
Half Duplex A channel which signals in both directions, but not simultaneously.
Handover/handoff What occurs when a cell phone used in a car moves out of the range of one cell and needs to connect to the next available cell. The preceding cell then hands over the connection to the stronger cell.
HDLC high Level Data Link Control.
Hertz A unit of frequency, which equals cycles per second.
High-Speed Downlink Packet Access (HSDPA) / 3.5G High-Speed Downlink Packet Access (HSDPA) is a mobile telephony protocol, also referred to as 3.5G (or 3�G) technology, which provides a smooth evolutionary path for UMTS-based 3G networks allowing for higher data transfer speeds, up to 14.4 Mbit/s per cell in the downlink and 2 Mbit/s per cell in the uplink. An evolution of the W-CDMA standard, HSDPA achieves the increase in the data transfer speeds by defining a new W-CDMA channel: a high-speed downlink shared channel (HS-DSCH) that operates in a different way from existing W-CDMA channels and is used for downlink communications to the mobile
Hypertext Transfer Protocol (HTTP) A protocol that is used to transmit hypertext documents through the Internet. It controls and manages communications between a Web browser and a Web server.
Hub In local area networks (LANs), a hub is a wiring concentrator equipment used in hierarchical star physical wiring topologies. Those directly connected to terminals or other user devices are often referred to as local hubs or concentrators. Central hubs are those at the highest hierarchical level. Hubs often provide the means for interconnecting 10BaseT, coaxial or fiber optic cable LAN segments. Intelligent hubs may implement multiport bridging and network management functions.
HSDPA High Speed Downlink Packet Access is a packet-based downlink data service, supported by WCDMA networks. It provides data transmission speeds up to 8-10 Mbps (which can be further enhanced to 20 Mbps using more advanced multi-input multi-output techniques) over a 5 MHz bandwidth. Most operators with WCDMA networks subsequently opt for HSDPA support in their 3G networks.

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IANA Abbreviation for Internet Assigned Numbers Authority. An organization directed by the Internet Architecture Board (IAB) and which assigns IP numbers and protocol parameters such as port, protocol, and enterprise numbers, and options, codes, and types.
IEEE 802.16 Commonly referred to as WiMAX or less commonly as WirelessMAN� or the Air Interface Standard, IEEE 802.16 is a specification for fixed broadband wireless metropolitan access networks (MANs) that use a point-to-multipoint architecture. Published on April 8, 2002, the standard defines the use of bandwidth between the licensed 10GHz and 66GHz and between the 2GHZ and 11GHz (licensed and unlicensed) frequency ranges and defines a MAC layer that supports multiple physical layer specifications customized for the frequency band of use and their associated regulations. 802.16 supports very high bit rates in both uploading to and downloading from a base station up to a distance of 30 miles to handle such services as VoIP, IP connectivity and TDM voice and data.
Incumbent Local Exchange Carrier (ILEC) Traditional telephone company. In the U.S., the Regional Bell Operation Companies (RBOCs) that were formed after the divestiture of AT&T and the Independent Operating Companies (IOCs) that usually are located in more rural areas or single cities are called ILECs.
Inbound Signaling Inbound signaling uses not only the same channel path as the voice traffic, but the same frequency range (band) used for the voice traffic.
Interactive Manual A Windows-based modem control and diagnostic program bundled free with each Option 2-in-1 modem.
Interconnection fees The process of originating calls from one service provider and terminating them to another service provider is called "interconnection." This interconnection between two systems is regulated through interconnection fees, which may be measured in units of time and capacity. A few years back, interconnection policies were adopted to mainly foster competition by requiring incumbents to provide interconnection to new competitors at regulated rates. However, with telecom convergence on the verge of fully materializing in some sectors, effective interconnection is now deemed a crucial factor toward expanding integrated ICT markets.
Intranet One to one connections over the Internet that are not accessible to all; mainly a private Internet set up internally for employee view only.
IP Centric A phone system built around an IP network, not a PBX (see PBX).
IP Telephony Allows voice traffic to travel over data networks; in the consumer market, traffic can go over the Internet; in the commercial market, this traffic typically goes over privately-owned data networks.
IPTV (Internet Protocol Television) IPTV (Internet Protocol Television) describes a system where a digital television service is delivered using the Internet Protocol over a network infrastructure, which may include delivery by a broadband connection. For residential users, IPTV is often provided in conjunction with Video on Demand and may be bundled with Internet services such as Web access and VoIP. The commercial bundling of IPTV, VoIP and Internet access is referred to as a Triple Play. Adding the mobile voice service leads to the Quadruple Play denomination. IPTV is typically supplied by a broadband operator using a closed network infrastructure. This closed network approach is in competition with the delivery of TV content over the public Internet. This type of delivery is widely called TV over Internet or Internet Television. In businesses, IPTV may be used to deliver television content over corporate LAN's and business networks. Perhaps a simpler definition of IPTV would be television content that, instead of being delivered through traditional formats and cabling, is received by the viewer through the technologies used for computer networks.
ISDN Integrated Services Data Network, phone line standards that allow for voice, video and data to be sent over digital phone lines or normal phone wires, data transfer rates of 64Kbps.
Independent Service Provider (ISP) Entities which provide telecommunications services over fixed or mobile networks, or services with a telecommunication service component, to the public at large but do not own or operate telecommunications networks. Some independent service providers may not use telecommunication networks e.g. they may be publishers of printed directories.
Intelligent Network A telecommunications network in which the network intelligence is centralized and separated from switching functions. This allows more flexibility than switched based systems in that customers can be given access to their own database entries to carryout changes.
Interoperability The technical features of a group of interconnected systems (systems include equipment owned and operated by the customer which is attached to the public telecommunication network) which ensure end to end provision of a given service in a consistent and predictable way.
ISO The International Standards Organization, the body responsible for setting world technical standards. It is based in Geneva, Switzerland.
Isochronous Signals Isochronous Signals are periodic signals in which the time interval that separates any two corresponding significant occurrences or level transitions is always equal to some unit interval or a multiple of that unit interval. For example, in digitized voice signals, ideally voice samples occur isochronously at precisely the sampling interval or frame rate. Packet data signals are not isochronous.
ITU International Telecommunications Union, based in Geneva, Switzerland.
IWU InterWorking Unit. This is the network "modem" where all the digital to analogue (and visa versa) conversions take place within the digital GSM networks.

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JPEG Joint Photographic Experts Group.
JTM Job transfer manipulation.
Jack A socket connector designed for the insertion of a plug, commonly used for audio devices (e.g. used for connecting your headphones to your audio equipment).

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Key System
Key telephone system (KTS): In a local environment, terminals and equipment that provide immediate access from all terminals to a variety of telephone services without attendant assistance. Note: A KTS may interface with the public switched telephone network. Key Systems are generally most appropriate in relatively small business environments, in the range of 50 telephones. Contemporary Electronic Key Telephone Systems (EKTSs), however, often cross the line into the PBX world, providing switching capabilities, as well as impressive functionality and feature content.

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Last Mile The last mile is the final leg of delivering connectivity from a communications provider to a customer. Usually referred to by the telecommunications and cable television industries, it is typically seen as an expensive challenge because "fanning out" wires and cables is a considerable physical undertaking. Outside the USA, the phrase "last kilometre" is sometimes used.
LAN Local Area Network - data communications network in a confined geographic area, usually within a building or campus; connects computers, printers, modems, servers, etc.
Latency An expression of how much time it takes for a packet of data to get from one designated point to another.
LATA Local Access and Transport Area - local geographic areas in the US where local phone companies can offer local and long distance telephone services.
LNP Local Number Portability allows a user to switch between local telephone companies without having to change the telephone number.
Loop Length Typically, loop length is a complete electrical circuit, the pair of wires that winds its way from the central office to the telephone set or system at the customer's premises.
Loop Signaling Loop signaling is a method of signaling over dc circuit paths that utilizes the metallic loop formed by the line or trunk conductors and terminating circuits.
Loop Start Loop start is a supervisory signal given at a telephone or PBX in response to closing the loop's DC current path.
Loop Transmission Facilities Loop transmission facilities connect switching systems to customer premises equipment throughout the serving area. A loop is a transmission path between a customer's premises and a LEC central office. The most common form of loop, a pair of wires, is also called a line. A loop" can be derived from digital loop carrier (DLC) systems also referred to as subscriber loop carrier (SLC) systems.
Lotus Famous for the Lotus 1-2-3 spreadsheet of the 1980's, and more recently for it's Notes Groupware system. Bought by IBM in 1995.
LRIC Long Run Incremental Cost is the forward-looking cost or change that a company expects to experience upon the production of an additional unit. In the telecom sector, LRIC is used to estimate the cost of a total service increment based on a theoretical model that simulates the actual network and associated costs.

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Metropolitan Area Network (MAN) A data communications network that (a) covers an area larger than a campus area network and smaller than a wide area network (WAN), (b) interconnects two or more LANs, and (c) usually covers an entire metropolitan area, such as a large city and its suburbs.
Media Gateway Control Protocol (MGCP) An Internet Engineering Task Force (IETF) draft standard for controlling voice gateways through IP networks.
Microsoft The world's largest developer and publisher of software based in Redmond, Seattle, USA. Headed by William (Bill) Gates, the richest (non-royal) person on this planet.
Microwave In telecommunications, microwaves have frequencies above 1 GHz.
Mobile number portability Where a customer taking a service from a mobile operator or service provider can retain their telephone number when they change to a different mobile operator or service provider.
Modulation A process whereby a signal is transformed from its original form into a signal that is more suitable for transmission over the medium between transmitter and receiver.
Modem Acronym for modulator /demodulator. In general, a device that both modulates and demodulates signals. In computer communications, a device used for converting digital signals into, and recovering them from, quasi-analog signals suitable for transmission over analog communications channels. Note: Many additional functions may be added to a modem to provide for customer service and control features. Synonym signal conversion equipment.
Mosaic A GUI (Graphical User Interface) for accessing the hypertext WWW (World Wide Web) on the Internet.
MNP Microcom Networking Protocol, Error control and data compression techniques, created by Microcom, that many newer modems use. They are built into the modem, unlike software error correction in file transfer protocols. There are different MNP levels. Levels 1-4 are error control protocols, and level 5 is a data compression protocol that can compress data to about 50% of its original size. A modem with MNP-5 also has MNP-4. MNP 1-4 is also included in the ITU V.42 error correction system.
MNP Mobile Number Portability allows consumers to retain their original cellular number when switching between cellular service providers.
MNP normal mode This is the more common mode used with modems that have MNP capability, where the speed from the computer to the modem can be higher than the connection between the modem and the remote modem. This mode uses buffering to prevent lost data.
MOU Memorandum of Understanding, the GSM body that overseas GSM standards and implementation around the world. It comprises operators and some manufacturers.
MPEG Moving Pictures Experts Group.
MTSO Mobile Telephone Switching Office.
Multiplexing Multiplexing is a technique that enables a number of communications channels to be combined into a single broadband signal and transmitted over a single circuit. At the receiving terminal, demultiplexing of the broadband signal separates and recovers the original channels. Multiplexing makes more efficient use of transmission capacity to achieve a low per channel cost. Two basic multiplexing methods used in telecommunications systems, are frequency division multiplexing (FDM) and time division multiplexing (TDM).
MVNO networks A Mobile Virtual Network Operator is a mobile operator that utilizes infrastructure and spectrum, owned by another mobile operator through business arrangements that allow it to buy air time (or minutes of use) for sale to its own subscriber base.

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National Frequency Plan The National Frequency Plan, which would a general plan for spectrum use and the basic structure to ensure effective use of the spectrum and the prevention of radio frequency interferences between services.
NCAIR National Center for Automated Information Research.
NGN Next Generation Networking (NGN), also referred to as Next Generation Network Architecture (NGNA), is a broad term for a certain kind of emerging computer network architectures and technologies. It generally describes networks that natively encompass data and voice (PSTN) communications, as well as (optionally) additional media such as video.The general idea behind NGN is that all information is transmitted via packets, like the Internet; packets are labelled according to their type (data, voice, etc) and handled differently for Quality of Service (QoS) and security purposes by traffic management equipment. In a NGN there is a more defined separation between the transport (connectivity) portion of the network and the services that run on top of that transport.
Network A system of computers linked together by communication channels allowing the flow of data between the linked computers.
Network Interface Card (NIC) An adapter circuit board installed in a computer to provide a physical connection to a network.
Network Operating System (NOS) NOS is software that controls the execution of network programs and modules. Structurally, networking software comprises multiple modules, most residing in network servers, but some must be installed in each terminal/station that can access network resources. Peer-to-peer NOS�s permit any terminal/station to act as a resource server or a client, and can be based on Microsoft's Disk operating system (MS DOS) designed for IBM and compatible PCs. Since MS DOS is not designed to run multiple programs and respond to many simultaneous users, most NOS�s designed for large networks with dedicated servers/superservers, have a multitasking and multi-user architecture. Advanced NOS products support network management, diagnostics, and administration, as well as, primary server, client, de vice and external network driver functions.
Non Transparent Cellular Data Non Transparent phones use a special error correction technique called RLP. Transparent phones data not incorporate the RLP error correction technique and their data MIGHT be corrupted.
Non Geographic Number These are numbers which are used to identify a type of service rather than a geographical location. These services are sometimes referred to as Specially Tariffed Services (STS) and include freephone, local rate, national rate and premium rate numbers. Mobile and personal numbers are also non geographic numbers.
Non Geographic Number Portability This is where a customer who has had allocated to him a non-geographic number associated with a particular type of service, such as 0800 free phone, an 07 personal number, or an 090 premium rate number, can retain that number when they change to a different operator or service provider offering a service of the same or similar type.
Number Portability Number portability between operators enables a customer to transfer from one operator to a second operator and retain the same number provided the customer remains at the same address.

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Open Systems Interconnection (OSI) standards OSI standards are standards for the exchange of information among systems that are "open" to one another by virtue of incorporating ISO standards. The OSI reference model segments communications functions into seven layers. Each layer relies on the next lower layer to provide more primitive functions and, in turn, provides services to support the next higher layer.
Optical Fiber(s) Optical fibers are light guides for electromagnetic waves in the infrared and visible light spectrum composed of concentric cylinders made of dielectric materials with different indices of refraction (i.e., velocity of propagation normalized to the velocity of light in free space). At the center is a core comprising the glass or plastic strand or fiber in which a light wave travels. A low index of refraction clad surrounds the core and is itself enclosed in a light-absorbing jacket that prevents interference among multi-fiber cables. Multi-fiber cable can be purchased with between 2 and 136 fibers.
OSS Operations support systems or operational support system.
Out Of Band Signaling Out of band signaling uses the same channel path as the voice traffic but signaling is in a frequency band outside that used for the voice traffic. In digital systems, out-of-band signaling may take the appearance of an allocated bit position or a dedicated channel or time slot.

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Parallel Port An output port on a PC that transmits data eight bits (one byte) at a time.
Parallel Transmission The simultaneous transmission of the signal elements of a character or other data item. In digital communications, the simultaneous transmission of related signal elements over two or more separate paths. Note: Protocols for parallel transmission, such as those used for computer ports, have been standardized by ANSI.
PABX Private Branch Exchange. This is the telephone system that many offices have, allowing extensions for each telephone, and a connection to the main telephone system.
Parity Bit Most modems have the capability to send an extra bit for every byte sent, which is used to help sense errors. This is called the parity bit. It can be set to no parity, mark parity, space parity, odd parity or even parity. Most BBS's do not use a parity bit.
PC Cards Previously known as PCMCIA cards, these are credit card devices used in notebooks and desktop readers for inter alia, data/fax, storage, GPS purposes.
PCMCIA A credit card sized card that generally plugs into a notebook computer. It conforms to the Personal Computer Memory Card International Association spec. Now known as PC Cards.
PSK Phase Shift Keying. In this method of modulation/demodulation, there are two frequencies used (usually 1200 hertz and 2400 hertz). There are 4 different phase angles (0, 90, 180, and 270 degrees), representing dibits 00, 01, 10, and 11. This is usually used for 1200bps transmission. Note that the baud rate using PSK is really 1/2 of the bps rate, since 2 bits are sent at a time instead of one. [See also modulation].
PSTN Public Switched Telephone Network. This is the regular phone lines that just about everybody uses.
Phreaker A person who spends a lot of time trying to find out as much as possible about the telephone company [like South Africa's TELKOM], and how it works. They often try to find out ways to make long distance calls for free. Some steal calls from telephone credit card users, some steal calls from the phone company directly, and others don't make "free" long distance calls. They are sometimes confused with hackers.
PKZIP The program which will create an archive with the extension "ZIP". It is one of the most popular archive programs.
Point-to-Point Protocol (PPP) Point-to-point protocol (PPP) is a connection oriented protocol that is established between two communication devices that encapsulates data packets (such as Internet packets) for transfer between two communication points. PPP allows end users (end points) to setup a logical connection and transfer data between communication points regardless of the underlying physical connection (such as Ethernet, ATM, or ISDN).
Pulse dialing A method that some phones use to dial numbers. It involves a series of "clicks." Most modems support this type of dialing, which is the only type available in some remote areas. The other method of dialing is tone dialing.
PRESUB Pre-subscription is an agreement that is made between the subscriber and the service provider on call rates and terms and conditions, before a call can be made.
Pre-subscription balloting This process allows prospective customers to choose between service providers through balloting, by taking into consideration services, costs, and related features that best suit their needs.
Protocols Protocols are strict procedures for the initiation, maintenance and termination of data communications. Protocols define the syntax (arrangements, formats and patterns of bits and bytes) and the semantics (system control, information context or meaning of patterns of bits or bytes) of exchanged data, as well as numerous other characteristics (data rates, timing, etc.).
Protocol Conversion Protocols are sets of rules that govern the exchanges between two telecommunication systems for the purpose of transferring information (signalling or data). Protocol conversion is where one set of rules is converted to another set of rules, to enable entities using different rules to exchange information.
Pulse Code Modulation (PCM) Pulse Code Modulation (PCM) is a modulation scheme involving conversion of a signal from analog to digital form by means of coding. See also modulation.

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QoS obligations These are measurements or QoS enforcements that are defined by the regulator in an operator's license as part of a quality-of-service framework.
Quantizing Noise In any analog to digital conversion process, e.g., PCM, quantizing noise is the difference between the converted binary value and the actual analog signal's amplitude.
Quality of Service (QOS) The idea that transmission rates, error rates, and other characteristics can be measured, improved, and, to some extent, guaranteed in advance.

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Radio Fixed Access Technology that enables operators to provide customers with direct connection to the public telecommunications� network via a fixed radio link from the home or premises to the local exchange, instead of providing a �wired� connection using copper cables or optical fibre.
Radio Spectrum The range of wavelengths used, for example, for broadcasting radio, terrestrial television and satellite television. Usable wavelength ranges from about 100 KHz to about 400 GHz although there are as yet no broadcasts above about 12 Ghz.
Radio Link Protocol (RLP) Non-transparent data uses a special ensure robust GSM-specific error correction technique called RLP for transmission. Both MTN and Vodacom GSM networks support both techniques.
Rate-Adaptive DSL (RADSL) This is a variation of ADSL, but the modem can adjust the speed of the connection depending on the length and quality of the line.
Real-time Transport Protocol (RTP) RTP is a packet based communication protocol that adds timing and sequence information to each packet to allow the reassembly of packets to reproduce real time audio and video information. RTP is a transport used in IP audio and video environments.
RPE-LPE Regular Pulse Excitation - Long Term Prediction, the speech coding used by GSM.
RACE Research and Development in Advanced Communication in Europe.
Redundancy Part of a message that can safely be omitted/deleted without ruining the integrity of a message; backup systems in case of main system failure.
Repeater In digital transmission, a repeater is equipment that receives a pulse train, amplifies it, retimes it, and then reconstructs the signal for retransmission. In IEEE 802 local area network (LAN) standards, a repeater is essentially two transceivers joined back to back and attached to two adjacent LAN segments.
Reset A modem can be reset. This will change any options (such as parity and speed) to the values that they have when the modem is first used. This can be useful if you change some values for the modem and aren't sure what they do, and then you find that the modem won't work. Resetting the modem will fix everything for you. With Option modems, this is the ATZ command.
RF Radio frequency.
RJ-11 This is a normal phone jack. The older South African plugs have a 3-prong connector. All Option modems sold in South Africa have this RJ-11-to-3-prong adapters.
Routers In IEEE 802 local area network (LAN) standards, routers are devices that connect autonomous networks of like architecture at the network layer (layer 3). Unlike a bridge which operates transparently to communicating end-terminals at the logical link layer (layer 2), a router reacts only to packets addressed to it by either a terminal or another router. Routers perform packet (as opposed to frame) routing and forwarding functions; they can select one of many potential paths based on transit delay, network congestion or other criteria. How routers perform their functions is largely determined by the protocols implemented in the networks they interconnect.
RTS Request To Send. This is when the computer tells the modem that it wants to send information to the other computer. It is only used in half duplex mode. [See also flow control, CTS].

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Synchronous Digital Hierarchy (SDH) A method of telephony transmission using digital techniques where the data is packed in containers which are synchronized in time enabling relatively simple modulation and demodulation at the transmitting and receiving ends. The technique is used to carry high capacity voice circuits over long distances.
Serial Transmission A method of transmitting data in which bits are sent sequentially.
SIG Special Interest Group. The GSM MoU has many SIGS.
Session Initiation Protocol (SIP) A standard protocol for initiating an interactive user session that involves multimedia elements such as video, voice, chat, gaming, and virtual reality.
Softphone (Software Telephone) A software program that runs on your PC (desktop or laptop) that allows you to make and receive calls over the Internet (VoIP). You can use a headset, or a microphone and speakers, in place of a telephone. A softphone's interface typically looks like a traditional phone dial pad. A softphone typically provides all the features and benefits associated with VoIP Solutions.
SIM Subscriber Identity Module. This is a Smart Card installed in every GSM handset. Within the GSM application the three primary roles of the SIM are access control to the network (authentication & ciphering), service personalization (SMS, advice of charge, etc.), network branding and advertising (graphics printed on SIM card). The new generation of Phase 2+ Sims will enable services such as virtual cash, mobile banking, ticket reservations etc.
Signal A signal is usually a time-dependent value attached to an energy propagating phenomenon used to convey information, for example, an audio or sound signal in which the data is characterized in terms of loudness and pitch.
Signaling Signaling is the process of generating and exchanging information between components of a telecommunications system to establish, monitor, or release connections (call handling functions) and to control related network and system operations (other functions).
Signaling System No. 7, SS #7 SS#7 is an international common channel signaling system recommendations established by the CCITT.
SMDR Station message-detail recording - A record of all calls originated or received by a switching system. Note: SMDRs are usually generated by a computer.
SMS Short Message Service will display a pager-like 160 character message in the LCD panel on the phone. Your phone must support SMS.
Signal to Noise ratio (SNR) The ratio of the amplitude of the desired signal to the amplitude of noise signals at a given point in time. [JP1] Note 1: SNR is expressed as 20 times the logarithm of the amplitude ratio, or 10 times the logarithm of the power ratio. Note 2: SNR is usually expressed in dB and in terms of peak values for impulse noise and root-mean-square values for random noise. In defining or specifying the SNR, both the signal and noise should be characterized, e.g., peak-signal-to-peak-noise ratio, in order to avoid ambiguity.
Streaming When data is sent continuously, without waiting to make sure there are no errors. Transparent mode on GSM is an example of a streaming method faster than non-transparent mode, but unreliable.
Switch A mechanical or electronic device that opens or closes circuits, completes or breaks an electrical path or selects paths or circuits. Switches with more than two ports are able to route traffic.
Switching Switching refers to the process of connecting appropriate lines and/or trunks to form a desired communications path between two station sets, or more generally, any two arbitrary points in a telecommunications network. Included are all kinds of related functions such as signaling, monitoring the status of circuits, translating address to routing instructions, alternate routing, testing circuits for busy conditions, and detecting and recording troubles.
Switched Access Long distance carrier access method in which a non-local call is carried by a local exchange carrier via a Central Office trunk for the first and last part of the call's journey and on the long distance carrier's network only for the middle part of the journey. Also called "switched to switched" or "off-net to off-net."

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Tariff A tariff is a published rate for a specific telecommunications service, equipment, or facility that constitutes a public contract between the user and the telecommunications supplier (i.e., carrier); tariff services and rates are established by and for telecommunications common carriers in a formal process in which carriers submit filings for federal or state government regulatory review, public comments, possible amendment, and approval.
T1 Trunk 1. A heavy duty telephone line.
T3 Trunk 3. A telephone trunk line.
TCP/IP Transmission Control Protocol/Internet Protocol - networking protocol used to connect network hosts, even with computers with very different hardware architectures and operating systems; network protocol of the Internet.
TDMA Time Division Multiple Access, the magical technique used by the digital GSM network to squeeze more calls onto one channel by dividing a calling channel into a few "discontinuous" pieces.
Telecommunication(s) This word has no precise definition, but is frequently used. Its definition ranges from "any form of communication over a distance" to "any communication by electric means" to "two computers 'talking' to each other via modems." Methods of communications that probably are considered telecommunications: telephones, cellphones, TV's and fax machines. The word is used both in singular and plural.
Telecommuting The idea of company employees working from home, rather than their office. At home, they can communicate with the office (and other entities) by modem or voice calls.
Telkom (South Africa) Telkom is the parastatal fixed-line network operator in South Africa. Option modems are approved for use on the telkom network and 25 other networks around the world.
TELNET A program which lets you access other computer systems through Internet.
Time-based In the time-based regime, interconnection charges are a function of time, local or transit interconnection, and services carried. This regime allows established operators to bill the competing operator on the basis of the number of minutes exchanged between the two networks.
Transceiver A transceiver is a generic term describing a device that can both transmit and receive. In IEEE 802 local area network (LAN) standards, a transceiver consists of a transmitter, receiver, power converter, and, for CSMA/CD LANs, collision detector and jabber detector capabilities. The transmitter receives signals from an attached terminal's network interface card (NIC) and transmits them to the coaxial cable or other LAN medium. The receiver receives signals from the medium and transmits them via the transceiver cable and NIC to the attached terminal. The jabber detector is a timer circuit that protects the LAN from a continuously transmitting terminal.
Transmission Medium Transmission medium is any material substance or "free space" (i.e., a vacuum) that can be, or is, used for the propagation of suitable signals, usually in the form of electromagnetic (including light waves), or acoustic waves, from one point to another; unguided in the case of free space or gaseous media or guided by a boundary of material substance.
Terminal Emulation When a communications program can simulate the operations of a smart terminal.
Toll Fraud Unlawful, unauthorized use of another's telecommunications system to make long distance phone calls. It typically involves compromising or tapping into a telephone customer's equipment, but it can also involve tricking an employee into giving away access to outside lines.
Tone Dialing This is a method that a phone or modem can use to dial a phone number. It uses one audible tone per digit to be dialed.
Transcoding The direct digital-to-digital conversion from one encoding scheme, such as voice LPC-10, to a different encoding scheme without returning the signals to analog form. Note: The transcoded signals, i.e., the digital representations of analog signals may be any digital representation of any analog signal, such as voice, facsimile, or quasi-analog signals.
Transmit Level The "loudness" level of the sound leaving a modem to go over the phone lines. It is measured indBm's. It should be different at different frequencies, since certain frequencies have more loss over the phone line than others.
Transparent Data Transmission A method of transmission in which the transmission medium will not recognize control characters or initiate any control function. Transparent-based phones do not utilise any error correction. Thus the data sent and received MIGHT be corrupted unless a greater than two-bar cellphone signal is used (South African conditions). Non-transparent data uses a special ensure robust GSM-specific error correction technique called RLP for transmission. Both MTN and Vodacom GSM networks support both techniques.
Triple-play Provision of combined traditional voice capabilities, Internet access and on-demand video services, offered as a bundled service over a broadband connection is referred to as triple-play.
Trunk A communication channel between two switching systems; usually refers to large bandwidth phone channels between switching systems that handle mass quantities of voice and data simultaneously.

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UART Universal Asynchronous Receiver/Transmitter, This is a device in a computer or modem that will change serial data (the way data comes in over the phone line) to parallel, and vice versa
User Datagram Protocol (UDP) In the Internet Protocol suite, a standard, low-overhead, connectionless, host-to-host protocol that is used over packet-switched computer communications networks, and that allows an application program on one computer to send a datagram to an application program on another computer. Note: The main difference between UDP and TCP is that UDP provides connectionless service, whereas TCP does not.
UNEs Unbundled Network Elements (or network facilities) are a part (a facility or equipment) of telecoms network that the incumbent service provider is required to offer a competing service provider, or customers, in attempts to maintain a fair competition in the market. Rates for such facilitations are determined by the regulatory body of the country. An example of a UNE is local loop, which is a connection from the incumbent operator's central office to a service subscriber's home or office line.
Unguided Media Unguided media is any medium in which boundary effects between "free space" and material substances are absent. The "free space" medium may or may not include a gas or vapor. Unguided media including the earth's atmosphere and outer space support terrestrial and satellite radio and optical transmission.
Universal Mobile Telecommunications System (UMTS) Universal Mobile Telecommunications System (UMTS) is one of the third-generation (3G) mobile phone technologies. It uses W-CDMA as the underlying standard, is standardized by the 3GPP, and is the European answer to the ITU IMT-2000 requirements for 3G Cellular radio systems.To differentiate UMTS from competing network technologies, UMTS is sometimes marketed as 3GSM, emphasizing the combination of the 3G nature of the technology and the GSM standard which it was designed to succeed.
Universal Service Obligation (USO) A specific requirement placed on an operator which has been designated to provide certain services to all specified persons. For example, eircom is currently required to provide basic voice telephony and certain other established telecommunications services to anyone who may reasonably request them.
Universal Service Provider An operator which has been designated to comply with specific obligations designed to ensure that a basic level of telephony service is available to everyone in the licensed area upon request.

V	Top
V.17 The ITU standard for fax transmission at 14,400bps.
V.21 The international standard, created by ITU, that controls transmission at 300bps.
V.22 The international standard for transmission at 1200bps, created by ITU.
V.22bis The international standard, created by ITU, that controls data transmission at 2400bps.
V.23 The ITU protocol for transmission of 1200bps one way, 75bps the other way.
V.24 This, combined with V.28 is the ITU standard equivalent to EIA's RS-232C standard. V.24/V.28 has 25 pins, just like the original RS-232C standard.
V.28 Part of V.24.
V.29 The ITU standard for 9600bps half-duplex communications.
V.32 The international standard controlling transmission at 9600bps. It was created by ITU. It has provisions for fallback, if the line is too noisy.
V.32bis The international standard for 14,400 bps modems, ratified by the ITU. V.34 The international standard for 28,800 bps modems, ratified by the ITU.
V.42 A standard error control system created by ITU that is in use on many 9600bps modems and some 2400bps modems. It includes LAPM, as well as MNP 2-4.
V.42 compatible This is a modem that follows all the V.42 specifications, except for LAPM error control (instead it uses MNP).
V.42 compliant This is a modem which follows all the V.42 specifications, and uses LAPM error control if possible. Otherwise, it will go to MNP error control.
V.42bis A ITU standard for data compression. It can compress data with about a 3:1 compression ratio, although it can compressup to 4:1 given the right conditions. Any modem with V.42bis also has V.42 error control.
Very High Bit Rate DSL (VDSL) Refer to DSL definition for more information on DSL. VDSL is a fast connection, but works only over a short distance.
VoFR Voice over Frame Relay - one of two main standards regarding voice transmissions over data networks; other standard is H.323
VoIP (Voice over Internet Protocol) The generic name for the transport of voice traffic using Internet Protocol (IP) technology. The VoIP traffic can be carried on a private managed network or the public Internet (see Internet telephony) or a combination of both. Some organisations use the term 'IP telephony' interchangeably with 'VoIP'.
Voice Telephony Service A service available to the public for the commercial provision of direct transport of real-time speech via the public switched network or networks such that any user can use equipment connected to a network termination point at a fixed location to communicate with another user of equipment connected to another termination point.
VPN (Virtual Private Network) These are used by a company or private group to make inter-site connections either for telephone speech or data as if there were dedicated leased lines between these sites. The equipment used is located within the public telecommunications operators� premises and forms an integral part of the public network but is software- partitioned to allow for a genuinely private network.
Video Conferencing Video conferencing is the real-time, usually two-way transmission of voice and images between two or more locations. Today, both voice and video analog signals are digitized by video codices before transmission which can involve wide bandwidths. To conserve bandwidth, some systems employ "freeze frame," where a television screen is only "repainted" every few seconds. Codecs for higher quality full motion video attempt to minimize bandwidth requirements by taking advantage of intervals with relatively little motion (which require smaller bandwidths), and by trading off smooth motion tracking and picture resolution.
Voltage Standing Wave Ratio (VSWR) In a transmission line, the ratio of maximum to minimum voltage in a standing wave pattern. Note: The VSWR is a measure of impedance mismatch between the transmission line and its load. The higher the VSWR, the greater the mismatch. The minimum VSWR, i.e., that which corresponds to a perfect impedance match, is unity.
VSAT A VSAT, for Very Small Aperture Terminal, is a 2-way satellite ground station with a dish antenna that is smaller than 3 meters, as compared to around 10 meters for other types of satellite dishes. VSAT is most commonly used for point of sale transactions including credit cards and RFID applications such as Mobil Speed pass. There are over 100,000 gas stations in the United States alone that use VSAT.

W	Top
W3 World Wide Web
WWW World Wide Web. A hypertext system set up on the Internet.
WAN Wide Area Network, data communications network that extends a LAN outside its geographic area, over common carrier lines, to link other LANs.
Waffle A DOS program to perform UUCICO.
Wavelength The distance between points of corresponding phase of two consecutive cycles of a wave. Note: The wavelength, λ, is related to the propagation velocity, v, and the frequency, f, by λ = v /f.
Wavelength-Division Multiplexing (WDM) In optical fiber communications, any technique by which two or more optical signals having different wavelengths may be simultaneously transmitted in the same direction over one fiber, and then be separated by wavelength at the distant end.
WCDMA Wideband Code Division Multiple Access is a wideband spread-spectrum mobile air interface that utilizes direct sequence CDMA signaling. This wireless transmission technique achieves much higher speeds and support more users as compared with older TDMA signaling method used in GSM networks.
Winsock A Windows subroutine library that provides access to the Internet TCP/IP.
WINSOCK.DLL The actual file containing Winsock.
WiMax Popular name of the 802.16 wireless metropolitan-area network standard that's currently being developed. WiMax, which will have a range of up to 31 miles, is primarily aimed at making broadband network access widely available without the expense of stringing wires (as in cable-access broadband) or the distance limitations of Digital Subscriber Line. There are two flavors of WiMax: 802.16-2004 or 802.16d, for fixed implementations, and 802.16e, for mobile service
Wireless Broadband Transmission facilities that have bandwidth or capacity greater than that of a voice line. Capable of carrying numerous voice, video and data channels simultaneously.
Wireless Intelligent Networks: WIN A sophisticated computer based network which, in conjunction with the switching system, allows for the rapid development of enhanced subscribers features and services.
Wireless local loop (WLL) Wireless local loop (WLL), also called radio in the loop (RITL) or fixed-radio access (FRA) or fixed-wireless access (FWA) or Fixed Wireless Terminal (FWT), is the use of a wireless communications link as the "last mile / first mile" connection for delivering plain old telephone service (POTS) and broadband Internet to telecommunications customers. Various types of WLL systems and technologies exist
WSP: Wireless Service Provider Any company that provides wireless service but which is not defined (for regulatory purposes)

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X.25 This is a packet-switching protocol developed by ITU. It is used to carry large amounts of data at fast speeds over leased phone lines.
X.32 This is ITU's 1984 update of X.25, also known as X.25 dialup.
X.400 This is the ITU standard protocol for a global system for the exchange of electronic mail.
X.500 The ITU standard for a directory of the users of the X.400 system.
Xmodem A file transfer protocol developed by Ward Christensen around 1977. It is fairly slow by today's standards, but was the first widespread file transfer protocol. It uses blocks of 128 bytes, and after each block is sent, it sends a 1 byte checksum to check for errors. If an error is encountered, the block will be re-sent. Almost every communications program offers this protocol.
Xmodem/CRC The same as Xmodem, but it has a 16-bit CRC instead of the checksum, which makes it more reliable (it catches more errors).
Xmodem-1K This is similar to Xmodem/CRC, except it uses blocks of 1024 bytes, rather than 128. It is faster than Xmodem, since it needs to stop less often to check for errors. This is sometimes incorrectly called Ymodem. [See also protocol, Xmodem, Ymodem].
Xoff The CTRL-S character. This is often used to pause information that is being sent. The information will be continued when an CTRL-Q is received. [See also flow control, Xon].
Xon The CTRL-Q character. This will sometimes continue paused information.
Xon/Xoff The flow control method using the Xon and Xoff characters. It is built into the software, not the hardware.

Z	Top
ZIP The file extension which refers to archives that were created by the program PKZIP. You need the program PKUNZIP to get the files out of the archive.
Zmodem A file transfer protocol which is known for its speed, as well as the ability to transfer information about the files which it sends. It has crash recovery and auto-download features, and can use a 32 bit CRC, which makes it almost error-free.