E-1
A transmission format defined at 2.048 Mbps. It is typically subdivided into 32 channels of 64 kbps each (typically only 30 channels are available for use). These are the standard requirements of most voice, fax and modem lines. The 32 channels are then multiplexed together to a single E1 and demultiplexed to the other end.

Earth Station
The term used to describe a combination of antennae, low-noise amplifier (LNA), down-converter and receiver electronics. It is used to receive a signal transmitted by the satellite.

Encryption
The process of scrambling files or programs, changing one character string to another through an algorithm (such as the DES algorithm).

Erbium Doped Fiber Amplifier
EDFAs are used for amplifying optical signals in long-haul optical networks. Unlike electro-optic repeaters, which convert light to electricity, amplify the signal, and then reconvert it to light, EDFAs amplify the light signal itself.

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 percent of the time.

Ethernet
The most widely used LAN access method, which is defined by the IEEE 802.3 standard. Ethernet is normally a shared media LAN meaning that all devices on the network segment share total bandwidth. Ethernet networks operate at 10 Mbps using CSMA/CD to run over 10BaseT cables.

Extranet
The extension of a company’s intranet out on to the Internet, for example, to allow selected customers, suppliers and mobile workers to access the company’s private data and applications via the world wide web.

Fast Packet Switching
An emerging, packet-orientated, digital technology that differs from traditional packet switching in a number of ways. The most obvious is that it transmits all data in a single packet format, whether the information is video, voice or data. Fast packet switching uses short, fixed length packets (cells) and via hardware switching is capable of speeds between 100,000 and 1,000,000 packets/second.

Fax on Demand
A system that enables callers to request documents, using their telephone keypads. The selected documents are delivered to the fax numbers they specify.

FDM
Frequency Division Multiplexing. A technique of dividing a single communication line into several data paths of different frequencies.

Fiber (Fiber Strand)
Optical fiber is made of flexible glass and can support very high data transfer rates. An individual glass fiber, roughly the thickness of a human hair, is capable of carrying a distinct signal transmitted in the form of pulses of light. A single strand of fiber is capable of transmitting over a million simultaneous telephone calls, or nearly 80 gigabits of digital information per second (80,000,000,000 pulses of light per second), using commercially available telecommunications equipment.

Fiber Optic Cable
A cable containing a bundle of fiber strands.

Fiber Optic Link
Any optical transmission channel designed to connect two end terminals or be connected in series with other channels.

Fiber Optics
Technology that involves sending laser light pulses via glass strands to transmit digital information.

Fixed-point Wireless
A point-to-point system sending microwave transmissions from one dish to another.

Follow-me Roaming
The ability of the cellular system to automatically forward calls to a roaming mobile that has left its primary service area.

Frame Relay
A technology for transmitting data packets in high-speed bursts across a digital network.

Frequency
The number of times that an alternating current goes through its complete cycle in one second of time. One cycle per second is also referred to as 1 Hz; 1000 cycles per second, 1 kHz; 1,000,000 cycles per second, 1 MHz; and 1,000,000,000 cycles per second, 1 GHz.

Frequency Division Multiple Access
Refers to the use of multiple carriers within the same transponder within which each uplink has been assigned a frequency slot and bandwidth. Usually used in conjunction with frequency modulation.

FTP
File Transfer Protocol. It is an application that runs over transport layer (TCP) and network layer (IP). It allows for bulk data (a large file) to be transferred from one computer to another with error-detection and retransmission.

Full Duplex
Refers to a communications system that uses two separate transmit and receive paths to allow simultaneous conversation in two directions.

Gateway
A device that links two different types of networks. A digital gateway links circuit-switched and packet-switched networks; the linking of two different types of networks using a combination of hardware and software.

Gbps
Gigabits per second. Equivalent to 1,000,000,000 bits per second

Geostationary Orbit
Refers to a geosynchronous satellite angle with zero inclination, so the satellite appears to hover (at an altitude of approximately 22,300 miles) over a spot on the earth’s equator.

GHz
GigaHertz. A frequency measurement which equals 1 million hertz.

Graphical User Interface (GUI)
This is a generic term for presentation on screen of computer information in a graphical form.

GSM
Global System for Mobile Communications. It is the digital transmission technique widely adopted in Europe and supported in North America for PCS. GSM uses 900 MHz and 1800 MHz in Europe. In North America, GSM uses 1900 MHz. Also see CDMA, PCS, TDMA.

GTAG
GTAG (Global Tag) is a standardization initiative of the Uniform Code Council (UCC) and the European Article Numbering Association (EAN) for asset tracking and logistics based on radio frequency identification (RFID).

Guaranteed Bandwidth
In networking or telecommunications, the capability for transmitting continuously and reliably at a specified transmission speed. The guarantee makes it possible to send time-dependent data (such as voice, video or multimedia) over the line.

Handoff
In cellular communications, handoff refers to the transfer of a connection from one cell to another. Handoff time is generally between 200 and 1,200 milliseconds (ms), which accounts for the delay you sometimes hear when talking to someone on a cellular telephone. In GSM, the term is handover.

Handoff (Intra-cell)
The process by which cellular subscribers traveling throughout the system coverage area are switched from cell sector-to-sector (and different channels) with better coverage for that particular area when poor quality conversation is detected.

Handshake
The process of two modems exchanging information via predetermined signals on how they will send data to one another, such as transmission speed, size of data packets, whether the operation will be full or half-duplex, etc.

Harmonic Filter
Used in the base station and subscriber transmitter circuits to remove unwanted harmonics from being transmitted and radiated by the antenna.

HDSL
High-bit rate Digital Subscriber Line, an enhanced form of the T1/E1 transmission system technology that allows telephone companies to use existing copper-cable plants while meeting the demands for updated services, including faster modem transmissions. Transmission rate can be supported up to 15,000 feet.

High Availability
In information technology, high availability refers to a system or component that is continuously operational for a desirably long period of time. Availability can be measured relative to ‘100 percent operational’. A widely-held but difficult-to-achieve standard of availability for a system or product is known as ‘five 9s’ (99.999 percent) availability.

High-speed Circuit
In telecommunications, circuits capable of faster transmission rates than are needed for voice communication. High-speed circuits generally support speeds of 20 kbps or more.

HIPPI
High-Performance Parallel Interface. A standard point-to-point protocol for transmitting large amounts of data at up to billions of bits per second over relatively short distances, mainly on LANs. HIPPI is considered an ideal technology for the transfer of ‘big data’, such as data warehouse updating, audio and video streams, and data backup within a range of up to 10 km. HIPPI uses a point-to-point link.

Horizontal Cabling
That portion of the telecommunications cabling that provides connectivity between the horizontal cross-connect and the work-area telecommunications outlet. The horizontal cabling consists of the transmission media, the outlet, terminations of the horizontal cables and horizontal cross-connect.

Hosting
This term can be used to refer to the housing of a website, e-mail or a domain.

HSCSD
High Speed Circuit Switched Data. A circuit-linked technology for higher transmission speeds, up to 57 kbps, primarily in GSM systems.

HSM
Hierarchial Storage Management. It is a policy-based management of file backup and archiving in a way that uses storage devices economically and without the user needing to be aware of when files are being retrieved from backup storage media. Although HSM can be implemented on a standalone system, it is more frequently used in the distributed network of an enterprise.

HTTP
HyperText Transport Protocol. The protocol for moving hypertext files across the Internet. Requires an HTTP client program on one end and an HTTP server program on the other end. HTTP is the most important protocol used in the world wide web.

Hybrid Satellite
Satellite that carries two or more different communication payloads (i.e. it supports both C-band and Ku-band transponders).

Hertz (Hz)
The unit of frequency measurement equal to one cycle per second. Also see MHz (MegaHertz).

IDC
Internet Data Centers. Telecom service providers, large/multinational corporations and government institutions need certain infrastructure facilities to deliver new and competitive solutions to meet their customers’ demands. These infrastructure facilities are called IDCs.

IEEE
Institute of Electrical and Electronics Engineers, New York, www.ieee.org. A membership organization that includes engineers, scientists and students in electronics and allied fields. It has more than 3,00,000 members and is involved with setting standards for computers and communications.

InfiniBand
InfiniBand is an architecture and specification for data flow between processors and I/O devices that promises greater bandwidth and almost unlimited expandability in tomorrow’s computer systems. In the next few years, InfiniBand is expected to gradually replace the existing peripheral component interconnect (PCI) shared-bus approach used in most of
today’s personal computers and servers. It offers throughput of up to 2.5 Gbps and support for up to 64,000 addressable devices.

INMARSAT
International Maritime Satellite Organization. Agency that operates a network of satellites for international transmissions
for all types of international mobile services, including maritime, aeronautical and land mobile.

IN
Intelligent Networks. An upgraded version of the current switched telephone network that allows for the quick and easy introduction of new and enhanced services.

Integrated Services Digital Network
A set of international standards for telephone transmission. Integrated Services Digital Network (ISDN) provides an end-to-end digital network, out-of-band signaling and greater bandwidth than older telephone services. The two standard levels of ISDN are basic rate interface and primary rate interface.

Intelligent Routing
This will route callers based on a number of parameters, including information on the caller, queue status, agent status and the present situation.

INTELSAT
International Telecommunications Satellite Organization. An agency that operates a network of satellites for international transmissions.

Interactive Web Response
IWR. Enables customers to transact business over the Internet, interacting with the company’s database, and transfer to an agent in a call center, continuing the inquiry over the phone.

Interconnection
The linkage, by wire, radio, satellite or other means, of two or more existing telecommunications carriers or operators with one another for the purpose of allowing or enabling the subscribers of one carrier or operator to access or reach the subscribers of the other carriers or operators.

Internet Telephony
Technology that enables users to place voice telephone calls through the Internet, thus bypassing the long distance network.

Intranet
A network of networks that uses the Internet but is contained within a controlled environment, for example, internal company information that is viewed only by employees.

Intrusion Detection
Techniques which attempt to detect intrusion into a computer or network by observation of actions, security logs or audit data. Detection of break-ins or break-in attempts either manually or via software expert systems that operate on logs or other information available on the network.

IP Number
Internet Protocol Number. Sometimes called a dotted quad. A unique number consisting of four parts separated by dots. Every machine that is on the Internet has a unique IP number—if a machine does not have an IP number, it is not really on the Internet.

IP Phone
Phone providing connectivity to the IP PBX. Features common phone options such as call hold, call forward, speed dial, transfer, calling line ID, call waiting and much more.

IP
Internet Protocol. IP is a method or protocol by which data is sent from one computer to another on a network, i.e. the Internet.

IRC
Internet Relay Chat. Basically a huge multi-user live chat facility. There are a number of major IRC servers around the world, which are linked to each other. Anyone can create a channel and anything that anyone types in a given channel is seen by all others in the channel. Private channels can (and are) created for multi-person conference calls.

ISDN Feature Phone
This terminal, in addition to having a handset and a dialing keypad, also has a LCD display, additional keys for storing frequently dialed numbers and other function keys. A caller can enter the digits to be dialed (which are displayed) since actual dialing does not take place as you press the digits but by an explicit action, say, lifting the hand set, etc. This reduces wrong calling. In case of CLIP service the calling number of call units charged is displayed. This is also used for programming of MSN, CF, etc.

ISDN Handset
It is the simplest type of ISDN terminal and consists of a handset and a phone unit. The telephone converts the user’s speech into digital form for communication on an ISDN line.