Comtech EF Data Vipersat CDM-570 User Manual page 155

E
Eb/No Eb/No Ratio Eb = energy per bit No = noise power density per Hz. The bit error
rate (BER) for digital data is a decreasing function of this ratio. Eb is the energy
of an information bit. Eb is measured in Joules, or equivalently in Watts per
Hertz.
E&M Ear & Mouth (literally) – The signaling leads used to carry telephone circuit
signaling or indicate circuit activity or status.
F
FDMA
Frequency Division Multiple Access – A technique where multiple users can
access a common resource (e.g. satellite) by each being allocated a distinct
frequency for operation. See also TDMA.
FEC
Forward Error Correction – A process whereby data being transmitted over a
communications link can have error correction bits added which may be used at
the receiving end to determine/correct any transmission errors which may occur.
FIFO
First In First Out – A simple buffer or queue technique whereby data queued
the longest is transmitted first.
FTP File Transfer Protocol – An application for transferring computer files over the
Internet. See also TFTP.
FXO Foreign eXchange Office – a 2 wire telephone interface that looks like a line
originating from a telephone exchange. See also FXS.
FXS Foreign eXchange Subscriber – a 2 wire telephone interface that looks like a
line coming from a telephone instrument. See also FXO.
G
G.729 ITU standard for LD-CELP (Low Delay – Code Excited Linear Prediction)
voice encoding at 8 kb/s.
GIR Guaranteed Information Rate
Group ID A number assigned to equipment which defines it as a member of a group when
addressed by the burst controller.
A p p e n d i x G l o s s a r y
E - E-3