Please take time to view our Glossary of Terms and Abbreviations - we hope you will find the information useful.
Second Generation mobile phone system
Third Generation mobile phone system
Fourth Generation mobile phone system
32-bit ABS encryption standard
The period of a signal containing data excluding the GI
Antenna Control Unit
Asymmetric Digital Subscriber Line
Advanced Encryption Standard
Avionics Full Duplex Ethernet
Automatic Gain Control
A finite list of well-defined instructions for accomplishing a task that, given an initial state, will produce through a well-defined series of successive states, eventually terminating in an end state.
Path loss exponent (rate of path loss change with distance)
Access Point Repeater
Antenna Receiver Site
American Standard Code for Information Interchange, a character encoding scheme
Asynchronous Serial Interface - this is a streaming format much like an MPEG Transport Stream MPEG-TS. It can contain a single program or be a multiplex of multiple programs, each consisting of video and audio. It is electrically identical to an SDI signal.
Amplitude Shift Keying
Automatic Test Equipment
American Wire Gauge
Additive White Gaussian Noise
Bars (pressure measurement)
Bit Error Rate - In telecommunications, an error ratio is the ratio of the number of bits, elements, characters or blocks incorrectly received to the total number of bits, elements, characters or blocks sent during a specified time interval. The most commonly encountered ratio is the bit error ratio (BER) - sometimes referred to as the bit error rate.
A device to enable a DC voltage to be applied to or extracted from a coaxial cable used to feed an antenna preamp or other line replacement unit using the coaxial feeder cable in addition to the RF signal as the DC supply cable.
Binary digit, taking the value of either 0 or 1
Bayonet Neill Concelman (type of connector)
Bits per second
Binary Phased Shift Keying
Carrier to Noise Ratio. In decibels (dB), is specified as the ratio between the power in the carrier of the desired signal and the total received noise power
Command Centre Site
Communications Control Unit
Crest Factor (peak to average power ratio of the RF envelope)
Referring to the FEC, code and bit interleaving, the code is used to protect data sent even in the presence of noise.
Compare against a specified standard
Video signal carrying colour image information
A device that transforms analog input into a digitally coded output and transforms digital signals to analog output
Coded Orthogonal Frequency Division Multiplexing - is a digital multi-carrier modulation scheme which uses a large number of closely spaced orthogonal sub carriers. Each sub carrier is modulated with a conventional modulation scheme at a low symbol rate, maintaining data rates similar to conventional single carrier modulation schemes in the same bandwidth.
Composite video is the format of an analog television (picture only) signal before it is combined with a sound signal and modulated onto an RF carrier. In contrast to component video it contains all required video information including colours in a single line-level signal.
Clear to Send - A control signal to the PC. The remote host is ready to receive your input. The host (remote DTE) may drop this from time to time as it becomes busy.
Composite Video Blanking Sync
Digital Electronic News Gathering
Digital Audio Broadcasting
In telecommunications and computing, a data stream is a sequence of digitally encoded coherent signals used to transmit or receive information that is in transmission.
Decibel (ratio in log scale)
Decibel relative to main signal power
dB(isotropic) The forward gain of an antenna compared with the hypothetical isotropic antenna which uniformly distributes energy in all directions. Linear polarisation of the EM field is assumed unless noted otherwise.
Decibel relative to 1 milliwatt
Direct Current (0 Hz)
Data Carrier Detect - a control signal to the PC. The modem is receiving a valid carrier signal from the remote modem. AKA Received Line Signal Detect (RLSD).
Data Communication Equipment - this is normally a Modem
Declaration of Design and Performance
Direct Digital Synthesis
One of the specific forms of Fourier analysis.
The act of changing a signal frequency to a lesser value (ie GHz to MHz) without altering the data imposed on it.
Differential Phase Shift Keying
Direct Sequence Code Division Multiple Access
Double Side Band Suppressed Carrier
Digital Signal Processing
Data Set Ready - a control signal to the PC. The Modem is ready to answer or originate a call - as opposed to being in a test mode.
Direct Sequence Spread Spectrum
Data Terminal Equipment - normally a PC, VDU or data terminal
Data Terminal Ready - a control signal for the PC. The PC uses this to enable the modem: the modem is allowed to go on-line or answer a call.
Digital Video Broadcasting
Digital Video Broadcasting - Cable
Digital Video Broadcasting - Satellite
Digital Video Broadcasting - Terrestrial
Energy per Bit to Noise Ratio
Electronic Counter Measures
Enterprise Control Systems Ltd
Encryption Control Unit
Electronics Telecommunications Union
Explosive Ordnance Disposal
Electrostatic Sensitive Devices
The hypothesised medium that surrounds the earth.
European Telecommunications Standard
Frequency Division Multiplexing (FDM) is a form of signal multiplexing where multiple baseband signals are modulated on different frequency carrier waves and added together to create a composite signal.
Forward Error Correction - a system of error control for data whereby the transmitter adds redundant data to its messages enabling the receiver to detect and correct errors.
Fast Fourier Transformation - a fast algorithm for performing a discrete Fourier transform
Finite Impulse Response (digital filter)
Frequency Modulation, analogue modulation technique
Full Motion Video
Field Programmable Gate Array
Frequency Shift Keying
Graphical Hand Held Controller
Guard Interval - a Guard Interval is used to ensure that distinct transmissions do not interfere with one another. The purpose of the GI is to introduce immunity to propagation delays, echoes and reflections, to which digital data is very sensitive.
Gaussian Minimum Shift Keying
Ground - the common signal ground connection. All other signals refer to this reference.
Global Positioning System
Global System for Mobile communications
Graphical User Interface
High Definition Multimedia Interface is an interface for digital video
High Definition Television
Base Unit of Frequency
International Electro technical Commission
Improvised Explosive Device
Intermediate Frequency, mixes frequencies up or down to other frequencies
Inverse Fast Fourier Transformation
Integrated Logistics Support
International Standards Organisation
Joint Photographic Experts Group
Kilobits per second
Kilobits per second
Low Noise Amplifier
Line of Site
Line Reflect Match
Line Replacement Unit
A photometric measure of emitted light.
Megahertz SI unit of frequency
Megabits per second
Moving Picture Experts Group - this is a standard used primarily to compress audio and visual (AV) digital data.
Moving Picture Experts Group - Transport Stream
Non Line of Sight
National Marina Electronics Association
National Television System Committee
Night Vision Goggles
Orthogonal Frequency Division Multiplexing - a multicarrier modulation scheme using a large number of closely spaced orthogonal sub carriers. Each sub carrier is modulated with a conventional modulation scheme at a low symbol rate.
At right angles
On Screen Display
Phase Alternating Line
Peak to Average Power Ratio
Pulse Code Modulation - a technique used to digitise analogue signals
Phase Locked Loop
Pseudo Random Sequence
Phase Shift Keying - this is a form of phase modulation which is accomplished by the use of a discrete number of states.
Power Supply Unit
Quadrature Amplitude Modulation - a modulation technique used to transmit digital signals
Quadrature Phase Shift Keying - QPSK is a phase modulation algorithm. The carrier wave is modulated to encode bits of digital information in each phase change. QPSK refers to PSK with 4 states.
Rapid Deployment Observation Kit
Remotely Controlled Improvised Explosive Device
Remote Control Unit
Remote Controlled Vehicle
Root Mean Squared
RS-232 is a serial bi-directional asychronous interface for wired data transmission
Received Signal Strength Indicator
Remote Static Video Downlink System
Request to Send - a control signal from the PC. The PC is ready to receive data. The PC may drop RTS from time to time as it spins its wheels - having to scroll text and other demanding tasks.
Receive Data - the data signal to the PC. What the user sees from the remote host.
Orientation of Connector Keyways
Specific Absorption Rates
System Control Unit
Serial Digital Interface - an interface for digital video and audio transmission
Single Frequency Network
International System of Units
Signal to Interference Ratio
Service Level Agreement
Sub Miniature Version A
Signal to Noise Ratio
The smallest bit of data transmitted at one time.
The gross bit rate, inclusive of channel coding overhead, divided by the number of bits transmitted in each symbol.
Time Division Multiplexing
Time Division Multiple Access
Transmit Data - The data signal from the PC, the data sent by the user.
Unmanned Aerial Vehicle
Ultra High Frequency
Universal Mobile Telecommunications System
The act of changing a signal frequency to a higher value (ie MHz to GHz) without altering the data imposed on it.
Universal Serial Bus is a 4-pin connection for data transfer between devices
Video Automatic Gain Controller
Voltage Direct Current
Very High Frequency
Video Link System - the facility to communicate real time Video/Audio/Data between two points.
Wireless Local Area Network
Wireless Local Loop