7E Communications
   

Glossary Terms Beginning B

0-9 : 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

Backhaul
Contribution circuit: traditionally a terrestrial communications path linking an earth station to a local switching network; now also refers to satellite contribution paths.
Back-off
Process of reducing the input and output power levels of a travelling wave tube to obtain more linear operation and hence minimize the risk of distortion. Expressed in dB.
Bandpass filter
Active or passive circuit which allows signals within the desired frequency band to pass but prevents signals outside this pass band from getting through.
Bandwidth
Measure of spectrum (frequency) use or capacity; the amount of information that can be passed at a given time over a certain span of frequency.
Basic rate ISDN
ISDN service of 2 64 kbps bearers and a 16 kbps data control channel. Also referred to as 2B+D.
Baud
Rate of data transmission based on the number of symbols transmitted per second; see Symbol.
Beacon
Low-power carrier transmitted by a satellite which supplies the satellite operations control centre on the ground with a means of monitoring telemetry data and tracking the satellite.
Beam
Signal from uplink or satellite.
Beamwidth
Angle or conical shape of the beam the antenna projects.
Bearer
Generic term for a carrier signal.
BER
Bit error rate: a measurement of the quality of a data link.
Binary
See Digital.
Bird
Colloquial term for satellite.
Bit
Single digital unit of information.
Bit error rate
See BER: the fraction of a sequence of message bits that are in error. A bit error rate of 10-6 means that there is an average of one error per million bits.
Bit-rate
Speed of a digital transmission, measured in bits per second.
Bit-stream
Continuous stream of data bits transmitted over a communication channel with no separators between the character group.
Bizphone
Land-line, cellular or satellite phone used for satellite co-ordination at the SNG uplink.
Block downconverter
Device used to convert the C- or Ku-band signal down to L-band.
Block
A group of pixels in a compression process.
Bonding
Method of combining a number (n) of discrete data channels of data bandwidth d to provide the user with a single combined data channel of nd. Boresight Main focus of an antenna; the direction of maximum gain of an antenna. Box Area in which the satellite has to be maintained while in station-kept geostationary orbit; see Station-kept box.
bps
Bits per second.
BPSK
Binary phase shift key: modulation technique.
BRI
Basic rate ISDN; Basic Rate Interface (for ISDN).
Broadband
Referring to a bandwidth greater than the baseband signal; a single path that has multiple independent carriers multiplexed onto it; a large bandwidth digital 'pipe'.
Broadbeam
See Widebeam.
BSS
Broadcast-Satellite Service: ITU service designation.
Buffer
Digital memory store on the input and output of a compression device.