Reference Materials Menu

SSS Online is your RF, Wireless, and SS Source!

Topical Menus:
   SSS Online Ezine
   Spread Spectrum
   RF Topics
   Wireless Topics
   Design Topics
   Tech Notes & Tips
   Design Tools
   Software Downloads
   Reference Material
   Ham Topics
   Fun & Games
   Assorted Topics
   Community Topics
   Site Info

This site is managed by:
Visit Pegasus Technologies
Pegasus Technologies Menu
Contact Us


Search site
Search Web
Leave a Comment

Sign our Guestbook

Another great source for definitions of information technology terms is CMP's TechEncyclopedia.

Define this term:


Visit our Sponsors:

Spread Spectrum Scene

    Spread Spectrum Online Glossary

Page 2, B-E

Why not try out some of our other features?

New Issue

What's New SS Projects Pegasus News Old Issues

About SSS

SS Secrets Wireless SS Enigmas About Pegasus

Click on a letter or numeral to find words and definitions.

[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] [Y] [Z]


Back Lobe
In an antenna, a radiation lobe whose axis makes an angle of about 180 degrees with respect to the beam axis of the antenna.

The range of frequencies, expressed in hertz (Hz), that can pass over a given transmission channel. The bandwidth determines the rate at which information can be transmitted through the circuit.
ALSO: The information capacity of a communications resource, usually measured in bits per second. Also see Narrowband, Wideband and Broadband.

A portion of a satellite antenna's footprint on earth. A typical satellite footprint is divided into a large number of beams.

In an antenna, the angular sector in degrees of the radiated power pattern at the half-power (3dB) point.

A signal relay scheme in which a terrestrial-based signal is sent to a satellite, which then relays the signal back to Earth with minimal processing by the satellite.

Bit Error Rate.

Bluetooth is the term used to describe the protocol of a short range (10 meter) frequency-hopping radio link between devices. It can be used to connect wireless phones to computing devices, etc.

Binary Phase Shift Keying -- Digital DSB suppressed carrier modulation.

A classification of the information capacity or bandwidth of a communication channel. Broadband is generally taken to mean bandwidth higher than 2 Mbps.

A signal transmitted to all user terminals in a service area, or the process.

Broadcasting satellite service (BSS)
A radio communications service in which signals transmitted or retransmitted by satellites are used for direct reception by the general public.


Code Division Multiple Access -- A way to increase channel capacity by using code sequences as traffic channels in a common radio channel. This technology was originally developed for military use over 30 years ago. Also -- A digital signal multiplexing technique where each signal is split into many chips of data, each of which is tagged with a particular code. During transmission, the chips are spread over a band of frequencies, then reassembled at the receiving end. This technique permits many different signals to be co-located in the same frequency band.

CDMA One (IS-95)
A narrowband, second generation digital air interface technology developed by the US firm Qualcomm.

3G evolved from CDMA One. The CDMA community's proposal for a system standard for 3G services.

Cell: The basic geographical unit of a cellular communications system. Service coverage of a given area is based on an interlocking network of cells, each with a radio base station (transmitter/receiver) at its center. The size of each cell is determined by the terrain and forecasted number of users.

Cell Splitting
A method of increasing capacity of a wireless system by reducing the size of the cell (local area near a transmitter).

The time it takes to transmit a bit or single symbol of a PN code.

Circuit switching
The basis of telephone call handling, with a circuit connection being set up between caller and called party. This connection is held open for the duration of the call, even when no information (voice, data, images or video) is being transmitted. The alternative is packet switching.

Circular Polarization
In an antenna, where the tip of the field vector, as viewed in the direction of propagation, rotates either clockwise (right hand) or counterclockwise (left hand).

Complementary Metallic Oxide Semiconductor.

Co-Channel Interference Reduction Factor (CIRF)
A key factor used to design a cellular system to avoid cochannel interference.

A digital bit stream with noise-like characteristics.

Co-linear Array
In an antenna, a linear array of dipoles with their axes lying in a straight line.

Continuous Time Oversampling
A technique Developed by Analog Devices that simplifies the job of synchronizing data generated from disparate sampling rates. The technique resamples and synchronizes modem, audio, and video data as needed, and it eliminates the substrate noise and feedthrough problems.

In the context of mobile communications, convergence means many things. There is convergence of industry sectors, including telecommunications, information, media and entertainment; convergence of technologies, for example, of fixed and mobile communications and of telecommunications and computing; and there is convergence between mobile communications standard themselves.

Core network
The physical network infrastructure to which the radio access network is connected in a mobile network.

The SS receiver component that demodulates a Spread Spectrum signal; a device that measures the similarity of of an incoming signal and a stored reference code.

A measure of the similarity of two different signals.

Cross Polarization
In an antenna, polarization orthogonal to a specified reference.


D-AMPS (IS-136)
Digital AMPS, the digital wireless standard widely used throughout the Americas, Asia Pacific and other areas. D-AMPS services can be introduced in the 800 MHz and 1900 MHz frequency bands. Uses a TDMA-based air interface.

Decibel; a logarithmic unit of power or intensity; 3 dB is twice the power.

Decibel, Isotropic; decibel referenced to the gain of a theoretical isotropic radiator.

Decibel, Milliwatt; decibel referenced to one milliwatt into 50 ohms (typical for RF systems).

Direct (to home) Broadcast (Satellite) System.

Distributed Control Systems, or DCS
An industrial measurement and control system routinely seen in factories and treatment plants consisting of a central host or master (usually called a master station, master terminal unit or MTU); one or more field data gathering and control units; and a collection of standard and/or custom software used to monitor and control field data elements. Unlike similar SCADA systems, the field data gathering or control units are usually located within a more confined area. Communications may be via a local area network (LAN), and will normally be reliable and high speed. A DCS system usually employs significant amounts of closed loop control.

Digital European Cordless Telecommunications - a standard issued by ETSI for local area digital cordless communications.

The process used by a correlator to recover narrowband information from a spread spectrum signal.

Diffraction Loss
The loss between two antennas caused by the scattering of energy from a knife-edged or rounded obstruction in the path between them.

Digital Cellular Telephone
A generation of car telephones served by a cluster of receiver-transmitter cell site receiver/transmitters; as the car travels, a telephone call is activated by transferring it from cell site to cell site.

Digital Network
A second generation cell phone network employing digital technology to convert the sounds of users' voices into streams of bits that are then used to modulate the wireless signals. Digital networks can also be used for data communications. These networks came into use in the 1990s.

Dipole Antenna
Any one of a class of antennas producing a pattern with a node or zero level at each end.

Directive Gain
In a given direction, 4pi times ratio of the radiation intensity in that direction to the total power radiated by the antenna.

Director Element
In an antenna, a parasitic element forward of the driven element intended to increase the directivity of the antenna in the forward direction.

Sharing a signal characteristic to allow more users in the same frequency band.

A radio link from a satellite to a receiving site on earth or in an aircraft.

Differential Phase Shift Keying -- a simplified BPSK where only data transitions are transmitted.

Duplex Operation
Operating method in which transmission is possible simultaneously in both directions of a telecommunications channel.


EDGE: Enhanced Data Rates for Global Evolution
an enhanced radio modulation technique for GSM and TDMA (ANSI-136) networks that expands radio timeslots to 48 kbit/s. When combined with GPRS, it gives a maximum bandwidth of 384 kbit/s per subscriber. Currently being pursued by GSM networks in Europe and AT∓T Wireless in the U.S.

Electronically Erasable Programmable Read Only Memory.

Enhanced GPRS, another term for EDGE.

electric field
In an antenna, the force field associated with the current distribution of an antenna element, tangential to the element and expressed in volts per meter. It is mutually perpendicular to the magnetic field.

Electromagnetic Interference (EMI)
Any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics/electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation products, and the like. EMI is also an engineering term used to designate interference in a piece of electronic equipment caused by another piece of electronic or other equipment. EMI sometimes refers to interference caused by nuclear explosion. Synonym: radio frequency interference.

The operating system for mobile multimedia being developed by Symbian.

Electronically Programmable Read Only Memory.

Extremely Low Frequency (ELF)
A signal in the frequency in the range from 30 to 300 kHz.

Extremely High Frequency (EHF)
A signal in the frequency range of from 30 to 300 GHz.

European Telecommunications Standards Institute. A body formed by the European Commission in 1998, which included vendors and operators. ETSI's purpose is to define standards that will enable the European market (particularly for its citizens) for telecommunications to function as a single market.

Click on a letter or numeral to find words and definitions.

[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] [Y] [Z]

Contents Site Map Pegasus Tech Navigation Home
  Tel: 865-717-9339   ||   FAX: 865-717-9904    ||   E-Mail:
This site © 1995-2008 by SSS Online, Inc. All rights reserved.
Revised October 23, 2008