Glossary of Terms

1G :The first generation of analogue mobile phone technologies including AMPS, TACS and NMT

2G : The second generation of digital mobile phone technologies including GSM, CDMA IS-95 and D-AMPS IS-136

2.5G : The enhancement of GSM which includes technologies such as GPRS

3G : The third generation of mobile phone technologies covered by the ITU IMT-2000 family

ADPCM : Adaptive Differential Pulse Code Modulation; a form of voice compression that typically uses 32kbit/s

Analogue : The representation of information by a continuously variable physical quantity such as voltage

ANSI : American National Standards Institute. A non-profit making US organisation which does not carry out standardisation work but reviews the work of standards bodies and assigns them category codes and numbers

ATA: Analogue Telephone Adaptor is a hardware device that connects a simple telephone to the Internet through a high speed bandwidth line.

Bandwidth: Bandwidth is the volume of data that can be transmitted over a communication line in a fixed amount of time. It is expressed in bits per second (bps) or bytes per second for digital devices and in cycles per second, or Hertz (Hz) for analogue devices.

Broadband: is a term used to define a high speed Internet connection, generally provided by cable TV, DSL or dedicated telecom lines. The high speeds are achieved by the carrying capacity of the cable that can carry multiple messages simultaneously.

CDMA : Code Division Multiple Access; also known as spread spectrum, CDMA cellular systems utilise a single frequency band for all traffic, differentiating the individual transmissions by assigning them unique codes before transmission. There are a number of variants of CDMA (see W-CDMA, B-CDMA, TD-SCDMA et al)

CDR : Call Detail Records; the record made within the cellular network of all details of both incoming and outgoing calls made by subscribers, The CDR is passed to the billing system for action.

Codec: Codec is a term that arises from the Compressor-Decompressor or enCOder/DECoder process. It is used for software or hardware devices that can convert or transform a data stream. For instance, at the transmitting end codecs can encode a data stream or data signal for easy transmission, storage or encryption. At the receiving end, they can decode the signal in the appropriate form for viewing. Codecs allow IP devices to communicate with TDM devices.

Data compression: This is the process that is used to compress large data files into mall files so that they use less bandwidth during transmission and less disk space when stored. The compression depends upon the repeatable patterns of binary 0s and 1s. The higher the number of repeatable patters, the higher is the compression. The right compression codes can compress data files to 40% of their original size. The graphics files can be compressed even more – from 20% to 90%.

DCS1800 : Digital Cellular System at 1800MHz, now known as GSM1800

DECT : Digitally Enhanced Cordless Telecommunications system, a second generation digital cordless technology standardised by ETSI designed for internal home and business use.

DSL modem: A DSL modem is a device that is used to connect one or more computers to the high speed DSL line provided by a DSL operator to gain access to the Internet. The customers use these modems to log on the net to download or transmit data. Since the DSL lines have high bandwidth capacity the data transfer speeds are very high.

DTMF : Dual Tone Multi Frequency; better know as Touch Tone. The tones generated by touching the keys on the phone are used for a variety of purposes including voice mail systems and voice messaging

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

FMC : Fixed Mobile Convergence – the convergence of mobile and fixed line technology.

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

GSM : Global System for Mobile communications, the second generation digital technology originally developed for Europe but which now has in excess of 71 per cent of the world market. Initially developed for operation in the 900MHz band and subsequently modified for the 850, 1800 and 1900MHz bands. GSM originally stood for Groupe Speciale Mobile, the CEPT committee which began the GSM standardisation process.

H.323: An ITU standard that lays down guidelines for real time voice and videoconferencing utilities on the Internet. The H.323 standard supports voice, video, data, application sharing and white boarding and defines media gateways for conversion to packets.

IMEI : International Mobile Equipment Identity

IMSI : International Mobile Subscriber Identity; an internal subscriber identity used only by the network

IP address: An IP address, also known as Internet Protocol address, is the machine number used to identify all devices that are connected to the net. Each device has its own unique number which it uses to communicate. This number is fixed in the case of those computing devices that have a fixed IP address. The rest are allotted a dynamic IP address, which is valid for the period they are connected to the net. The numbers range from 0.0.0.0 to 255.255.255.255.

IP Phone: An IP phone is one that converts voice into digital packets and vice versa to make phone calls over Internet possible. It has built-in IP signaling protocols such as H.323 that ensure that the voice is routed to the right destination over the net. The IP phones come with several value added services like voicemail, e-mail, call number blocking etc.

IP telephony: IP telephony refers to the two-way transmission of voice over Internet. The voice is transmitted in real time by using the packet-switched technology over the IP network. Some of the applications that use IP telephony are IP-based phone services, voice over instant messaging and videoconferencing.

IP: IP, which is the acronym for Internet Protocol, defines the way data packets, also called datagrams, should be moved between the destination and the source. More technically, it can be defined as the network layer protocol in the TCP/IP communications protocol suite.

Jitter: It is a term used to indicate a momentary fluctuation in the transmission signal. This happens in computing when a data packet arrives either ahead or behind a standard clock cycle. In telecommunication, it may result from an abrupt variation in signal characteristics, such as the interval between successive pulses, also generally known as the variance in delay.

Kbps: Kbps is the acronym for kilobits per second and is used to indicate the data transfer speed. If the modem speed, for instance, is 1 Kbps then it means that the modem can route data at the speed of one thousand bits per second.

Latency: Latency is the time that elapses between the initiation of a request for data and the start of the actual data transfer. This delay may be in nanoseconds but it is still used to judge the efficiency of networks. Commonly known as delay.

MGCP: Acronym of Media Gateway Control Protocol. Used for a Voice over IP system. It consists of a Call Agent and a set of gateways, of which at least one works as the "media gateway" and performs the conversions.

Packet loss: Packet loss is the term used to indicate the loss of data packets during transmission over a computer network. This may happen on account of high network latency or on account of overloading of switches or routers that are unable to process or route all the incoming data.

Packet switched networks: These are networks that break messages into small digital packets, stamp each packet with the destination IP address, and route them across different channels to their destination where they are reassembled in their proper sequence. This is done to avoid network congestion and speed up data movement from multiple sources.

Packet: A packet is a unit of data transmitted over the network in a packet-switched system. It consists of a header that stores the destination address, a data area which carries the information that is being transmitted, and a trailer which contains information to prevent errors during transmission.

PCM : Pulse Code Modulation; the standard digital voice format at 64kbit/s

Protocol: It is a convention or standard that defines the procedures to be adopted regarding the transmission of data between two computing end points. These procedures include the way the sending device should sign off a message or how the receiving device should indicate the receipt of a message. Similarly, the protocols also lay down guidelines for error checking, data compression, and other relevant operational details.

PSTN: PSTN, which stands for Public Switched Telephone Network, refers to the telephone system that transmits analog voice data. Till recently, PSTN was the heart of all phone systems worldwide. However, most of the developed world is now switching to or has switched to telephone networks that are based on digital technologies, such as ISDN and FDDI. RJ45: RJ45, which is the acronym of Registered Jack-45, is a telephone connector that is used in Ethernet and Token Ring Type 3 devices. It has eight "pins" or electrical connections.

Router: A router is a network device that that handles message transfer between computers that form part of the Internet. The messages, which are in the form of data packets, are forwarded to their respective IP destinations by the router. A router can also be called the junction box that routes data packets between computer networks.

Service provider: A service provider is a business entity that provides a communication, storage or processing service for a fee. Some of the service providers in the digital world are the Internet service provider (ISP), application service provider (ASP), storage service provider, mobile phone service provider, web hosting provider, and of course, VOIP service provider.

SIM : Subscriber Identity Module; A smart card containing the telephone number of the subscriber, encoded network identification details, the PIN and other user data such as the phone book. A user’s SIM card can be moved from phone to phone as it contains all the key information required to activate the phone

SIP phone: A SIP phone is a telephone that uses the SIP (Session Initiation Protocol) standard to make a voice call over the Internet. The SIP phones come with several value added services like voicemail, e-mail, call number blocking etc. There are no charges for making calls from one SIP phone to another, and negligible charges for routing the call from a SIP phone to a PSTN phone.

SIP: SIP, which is the acronym of Session Initiation Protocol, is an IP telephony signaling protocol. It is primarily used for voice over IP (VoIP) calls, though with some extensions it can also be used for instant messaging. It is less complex than H.323, the other IP telephony protocol.

SMS : Short Message Service; a text message service which enables users to send short messages (160 characters) to other users. A very popular service, particularly amongst young people, with 400 billion SMS messages sent worldwide in 2002

Soft switch: It is a software application that is used to keep track of, monitor or regulate connections at the junction point between circuit and packet networks. This software is loaded in computers and is now replacing hardware switches on most telecom networks.

Symbian : A company created by Psion, Nokia, Ericsson and Motorola in 1998 with the aim of developing and standardising an operating system which enable mobile phones from different manufacturers to exchange information. The operating system is known as EPOC. Matsushita has subsequently joined Symbian

UMTS : Universal Mobile Telecommunications System; the European entrant for 3G; now subsumed into the IMT-2000 family as the WCDMA technology.

Voice over IP (VoIP): is the technology that is used to transmit voice over the Internet. The voice is first converted into digital data which is then organized into small packets. These packets are stamped with the destination IP address and routed over the Internet. At the receiving end the digital data is reconverted into voice and fed into the user’s phone.

VoIP Gateway: This device provides the conversion interface between the public switched telephone network (PSTN) and an IP network for voice and fax calls. Its primary functions include: voice and fax compression/decompression, packetization, call routing and control signaling. It also provides an interface to Gatekeepers or Softswitches, billing systems, and network management systems.

VoIP PBX: VoIP PBX, which stands for Voice over Internet Protocol Private Branch eXchange, is a telephone switch that converts IP phone calls into traditional circuit-switched TDM connections. It also supports traditional analog and digital telephones.

VoIP Phone: A VoIP phone is one that uses the Internet to route voice calls by converting the voice data into IP packets and vice versa. The phones come with built-in IP signaling protocols such as H.323 or SIP that help in the routing of data to the right destination. A VoIP phone can also be a software application that is installed in the user's PC. In this case it is known as the Softphone. Also, the calls in this case have to be made from the PC, and not through a telephone instrument.

VoIP services: The VoIP services are packet-based services that use the Internet to move voice data. These services are much cheaper than the traditional PSTN services because the investment in infrastructure is low. They also come with several value added features which make them more lucrative than the conventional landline phone services.

WAP : Wireless Application Protocol; a de facto standard for enabling mobile phones to access the Internet and advanced services. Users can access websites and pages which have been converted by the use of WML into stripped-down versions of the original more suitable for the limited display capabilities of mobile phones

WiFi Hotspot: An area where a wireless access point enables users carrying wireless-enabled laptops to log on to the Internet. The limiting condition is that the access point is configured to broadcast its presence and does not require authorization for access. Generally, WiFI hotspots are located in public places like airports, train stations, libraries, marinas, convention centers, coffee shops and hotels.

WiFi phone: A WiFI phone is one that enables users to make phone calls from public WiFi hotspots or residential WiFI network environments. Besides voice calls, these phones can be used to send e-mails wirelessly.

WLL : Wireless Local Loop; a technique for providing telephony and low speed data services to fixed customers using wireless. Regarded as having considerable potential for rapidly addressing the telecommunications gap in developing countries. A number of different WLL solutions have been marketed based on cellular and cordless technologies

WLAN : Wireless Local Area Network; a short range radio network normally deployed in traffic hotspots such as airport lounges, hotels and restaurants. WLAN enables suitably equipped users to access the fixed network wirelessly, providing high speed access (up to 11Mbit/s download) to distant servers. The key WLAN technologies are the IEEE802.11 family and ETSI HIPERLAN/2