Acoustic Coupler
A device that enables a modem to connect to a voice circuit. A handset adapter is used to receive modem tones through the handset’s mouthpiece, and the earpiece is used to transmit these tones to the modem.

Adapter
A mechanical media termination device designed to align and join fiber-optic connectors. Often referred to as a coupling, bulkhead or interconnect sleeve.

AMPS
Advanced Mobile Phone Service. The analog wireless transmission standard (technology) deployed in the 1980s in the US and Canada. AMPS operates at 800 MHz. Also see N-AMPS (Narrowband AMPS).

AMSS
Automatic Multiple Site Switching. This will allow the mobile radio unit to make a wide area call.

Antenna
A physical device for sending or receiving radio signals. Antennae come in a variety of shapes and sizes. Some wireless phones contain built-in antennae.

Aperture
A cross sectional area of the antenna, which is exposed to the satellite signal.

Application Level Gateway
A firewall system in which service is provided by processes that maintain complete TCP connection state and sequencing. Application level firewalls often readdress traffic, so that the outgoing traffic appears to have originated from the firewall rather than the internal host.

ASIC
Application Specific Integrated Circuits. These are custom designed to handle specific operations; all functionality is cast in hardware.

Asynchronous Mode
A way to send transmissions by starting and stopping transmissions with a code rather than sending transmissions at specific time intervals as in synchronous mode.

ATDM
Asynchronous Time Division Multiplexing

ATM
Asynchronous Transfer Mode. A technology for broadband transmission of high-capacity telecommunications signals. In addition to high-capacity signal transmission, ATM provides considerable flexibility, since the individual subscriber is able to adapt the capacity of a switched connection to current requirements.

Automatic Call Distributor
The specialized telephone system used in incoming call centers. It is a programmable device that automatically answers, queues and distributes calls to agents, plays delay announcements to callers and provides real-time and historical reports on these activities.

B Channel
In an ISDN system, it is the bearer channel that carries voice or data at 64 kbps in either direction. This is in contrast to the D channel, which is used for control signals and data about the call. Several B channels can be multiplexed into higher-rate H channels.

Backbone
A high-speed line or series of connections that forms a major pathway within a network. The term is relative, as a backbone in a small network will likely be much smaller than many non-backbone lines in a large network.

Band
In wireless communication, band refers to a frequency or contiguous range of frequencies.

Bandwidth
The width or capacity of a communications channel. Analog bandwidth is measured in Hertz (Hz) or cycles per second. Digital bandwidth is the amount or volume of data that may be sent through a channel, measured in bits per second, without distortion.

Base Station
The central radio transmitter/receiver that maintains communications with a mobile radio telephone with a given range.

Baseband
In networking, a baseband connection is one that uses digital signals, which are sent over wires without modulation; that is, binary values are sent directly as pulses of different voltage levels rather than being superimposed on a carrier signal (as happens with modulated transmissions).

Beacon
A low-power carrier transmitted by a satellite, which supplies the controlling engineers on the ground with a means of monitoring telemetry data, tracking the satellite or conducting propagation experiments. This tracking beacon is usually a horn or omni antenna.

BISDN
Broadband ISDN. A packet switching technique that uses packets of fixed length, resulting in lower processing and higher speeds.

Bit
A single digit number in base-2, in other words, either a 1 or a zero. The smallest unit of computerized data. Bandwidth is usually measured in bits per second.

Blackout
Total loss of utility power.

Blocked Call
A call that cannot be connected immediately because no circuit is available at the time the call arrives, or the ACD is programmed to block calls from entering the queue when the queue backs up beyond a defined threshold.

Bluetooth
An industry-standard for a low power short-range radio link for connecting electronic devices. Devices such as mobile phones, laptop computers and digital cameras equipped with Bluetooth can share data information within a range of about 10 meters. Neither cables nor line-of-sight infrared are needed.

BPS
Bits Per Second. A measurement of how fast data is moved from one place to another. A 28.8 modem can move 28,800 bits per second.

Bridge
A device that connects and passes network segments that use the same communications protocol. Bridges operate on the data link layer (layer 2) of the OSI reference model.

Broadband
A local area network (LAN) residing on coaxial cable capable of transporting multiple data, voice and video channels. Broadband channels have enough bandwidth to carry full motion video, stills, graphics, audio and text (e.g., fiber optics, cable TV, ITFS)

Burst Speed
The maximum speed at which a device can operate without interruption, generally only for short periods. This is in contrast to throughput, which indicates the average speed at which a device can operate under ordinary conditions.

C Band
Band of frequencies used for satellite and terrestrial communications. Range of frequencies from 4 to 6 GHz (billion cycles per second) is used by most communications satellites. The 3.7 to 4.2 GHz satellite communication band is used as the downlink frequencies in tandem with the 5.925 to 6,425 GHz band that serves as the uplink.

Call Accounting
Call accounting applications involve using software to track information about individual calls (number dialed, time, length, etc) in order to track usage, recover costs, bill for services, reconcile bills and more. Call accounting applications are generally easy to justify in environments where telephone use is intensive and time is billed.

Call By Call Routing
The process of routing each call to the optimum destination according to real-time conditions.

Call Detail Recording
Data on each call, captured and stored by the ACD. Can include trunk used, time in queue, call duration, agent who handled the call, number dialed (for outgoing calls) and other information.

Call Park
A call park number allows the user to ‘park’ a call at a specified directory number, go to another phone and dial the ‘park’ number to retrieve the call. This is different from ‘Hold’ because the user can retrieve the call from any phone on the same system.

Caller ID Features
Caller ID service is available from most local telephone companies. With a product equipped for caller ID, the service allows consumers to see the name and/or number of the calling party before answering their call.

Call Routing
Call routing solutions are also programmed telephony solutions that automate the delivery of calls to the selected individuals. Calls can be routed based on associated information provided by the telephone system, or on an actual interaction with a caller, using voice processing.

Call Screening
Call screening solutions use CTI technology to filter calls and handle them differently, depending upon who is calling or why. Call screening solutions may involve screen-based telephony, programmed telephony software or a combination of the two.

Carrier Frequency
The rate at which the carrier signal repeats, measured in cycles per second or hertz. The main frequency on which a voice, data or video signal is sent. Microwave and satellite communications transmitters operate in the band from 1 to 14 GHz (a GHz is one billion cycles per second).

Carrier
A company that provides telecommunications circuits. Carriers include both local telephone companies and long distance providers.

Category 5
A performance classification for twisted-pair cables, connectors and systems. Specified to 100 MHz. Suitable for voice and data applications up to 155 Mbps (possibly 1,000 Mbps).

Category 5e
Also called Enhanced Category 5. A performance classification for twisted-pair cables, connectors and systems. Specified to 100 MHz. Suitable for voice and data applications up to 1,000 Mbps.

CCITT X.25
CCITT specification and protocol for public packet-switched networks

CCITT
Consultative Committee on International Telegraph and Telephone. Older international standards body. Now called the ITU, it has been superseded by a new organization, the TSB, which will continue to recommend and publish worldwide communications standards. Also see ITU-TSS

CDPD
Cellular Digital Packet Data. A technology for wireless mobile communications.

Cell
The geographic area encompassing the signal range from one base station (a site containing radio transmitter/receiver and network communication equipment). Wireless transmission networks are comprised of many hexagonal, overlapping cell sites to efficiently use radio spectrum for wireless transmissions. Cells can be anywhere from a few km to 32 km (20) miles in diameter. Also the basis for the term ‘cellular phone’.

Cellular
In wireless communications, cellular refers most basically to the structure of the wireless transmission networks, which are comprised of cells or transmission sites. The term ‘cellular phone’ is used interchangeably to refer to wireless phones.

Channel
A channel is a physical or logical path for a signal transmission. Channel frequencies are specified by respective governments. In telecommunications, a single cable may be able to provide multiple channels. Television signals require a 6 MHz frequency band to carry all the necessary picture detail.

Circuit Switching
A switched circuit is only maintained while the sender and recipient are communicating as opposed to a dedicated circuit which is held open regardless of whether data is being sent or not.

Circuit-switched Gateways
The process of configuring and maintaining an open circuit between two or more gateways so those gateways have the exclusive use of the circuit until the connection is released.

CMTS
Cellular Mobile Telephone System. A cellular mobile radio system interconnected to a local telephone or to the public telephone network.

Coax, Coaxial Cable
Also called coaxial line. A transmission line in which the inner conductor is completely surrounded by an outer conductor (the shield—either a solid metal or braided metal grounded shield), so that the inner and outer conductors are coaxially separated. The line has no external field and it is not affected by external fields.

Co-Location
The ability of multiple satellites to share the same approximate geostationary orbital assignment frequently due to the fact that different frequency bands are used.

Computer Telephony Integration
The software, hardware and programming necessary to integrate computers and telephones so that they can work together seamlessly and intelligently.

Conditional Routing
The capability of the ACD to route calls based on current conditions. It is based on ‘if-then’ programming statements. For example, ‘if the number of calls in agent group 1 exceeds 10 and there are at least 2 available agents in group two then route the calls to group two.’

Connector
A mechanical device used to align and join two fibers together to provide a means for attaching to and decoupling from a transmitter, receiver or another fiber (patch panel).

Control Channel
The RF channel that is used to communicate to all mobiles. This tells the mobiles about the incoming telephone calls, what channel to go to for dispatch and interconnect calls, and other more technical things. It will always be on channel one, two, three or four.

Copper Cables
Assembly of one or more twisted-pair insulated conductors enclosed in a protective sheath, such as polyethylene, aluminum, lead, etc. Commonly used in telephony works.

Current Loop
A communications method that transmits data as current flow over relatively long distances and through environments with relatively high noise.

Customer Relationship Management
Where companies use a variety of methods and contact strategies to try to build lasting and profitable relationships, in order to retain the best customers and generate profitable revenue.

D Channel
In an ISDN system, the D channel is the data or signaling channel. The D channel is used for control signals and data about the call. This is in contrast to the B channel, which serves as a bearer for data and voice.

DAMA
Demand-Assigned Multiple Access. In telecommunications, a method for allocating access to communications channels. Idle channels are kept in a pool. When a channel capacity is requested, an idle channel is selected, allocated the requested bandwidth, and assigned to the requesting party. Typically used in a packet-switched environment.

Dark Fiber
A fiber strand without any light flowing through it. With DWP’s dark fiber, customers may attach their choice of voice, data and/or video equipment to the ends of their licensed fibers to ‘light’ the fibers and transmit information between locations.

Data Compression
The process of reducing the size of data parcels to transmit more data in less time. In modems, a bit encoding process that removes redundancy from the scanned page, resulting in fewer bits to transmit.

Data Port
Any PC with RS 232C connection (serial port of the PC) can be connected to this port, data transfer using standard software packages like X talk or ProComm is possible up to 9.6 kbps. A modem is not required.

Data Rate
The speed, measured in bits per second, at which a particular network (or other application) transmits data.

Data Services
The ability to access services such as e-mail, faxes and SMS messages using a wireless
phone or communicator. Also
see SMS.

DBS
Direct Broadcast Satellite. Refers to service that uses satellites to broadcast multiple channels of television programming directly to home mounted small-dish antennae.

Dead Spot
An area within the coverage area of a wireless network in which there is no coverage or transmission falls off. Dead spots are often caused by electronic interference or physical barriers such as hills, tunnels and indoor parking garages.

DECT
Digital Enhanced Cordless Telecommunications. A common standard for cordless personal telephony originally established by ETSI, a European standardization body. DECT is a system for cordless business communications.

Denial of Service
An attack that renders a site unavailable for use. Usually accomplished by bombarding a site with so many requests for information that it crashes or slows down; may also be done by interrupting network connectivity at the router or switch.

Dialed Number Identification Service
A string of digits that the telephone network passes to the ACD, VRU or other devices, to indicate which number the caller dialed. The ACD can then process and report on that type of call according to user-defined criteria. One trunk group can have many DNIS numbers.

Dial-up Line
A dial-up line is a non-dedicated communications line in which a connection can be established by dialing the number or code associated with the destination. A common example of a dial-up line, also called a switched line or public line, is the public telephone line. Dial-up lines generally support speeds of 2,400 to 9,600 bps.

DID
Direct Inward Dial, where you can dial directly into a company and reach an extension without going through a switchboard operator.

Digital Certificates
Digital certificates are used to positively identify a person or organization and it establishes their credentials when doing business or conducting other transactions on the web. A certificate authority issues a digital certificate.

Downlink
A satellite receive system that processes satellite delivered information, and includes the satellite itself, the receiving earth station and the signal transmitted downward between the two.

DSL
Digital Subscriber Line. DSL uses standard telephone lines to send high-speed Internet to homes and businesses. Local digital network loop. Always on. Download speeds up to 1.544 Mbps.

DSP
Digital Signal Processor. A DSP analyzes and processes analog signals, converting them to a digital format.

DSSS and FHSS
Direct sequencing spread spectrum (DSSS), and frequency hopping spread spectrum (FHSS) are spread-spectrum techniques that operate over the radio airwaves in the unlicensed ISM band (industrial, scientific, and medical). DSSS uses a radio transmitter to spread data packets over a fixed range of the frequency band. FHSS uses a technique by which the signal transmitted hops among several frequencies at a specific rate and sequence as a way of avoiding interference.

DTMF
Dual Tone Multi-Frequency. A system used by touch-tone telephones where specific frequencies or tones are assigned to each key, so that it can be easily identified by a microprocessor.

Dual Band
Dual Band mobile phones can work on networks that operate on different frequency bands. This is useful if you move between areas covered by different networks. For example, GSM 900 and GSM 1800.

Dual Mode
Dual mode mobile phones work on more than one network (for example, TDMA and AMPS, GSM and DECT).

Duplex
Refers to two-way communications. Full duplex is similar to th ephone in that both directions of communication occur at the same time. Half duplex is like a walkie-talkie.

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).

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.

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.

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.

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.

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).

Hz (Hertz)
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.