Appendix E - Glossary E-3
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.
EEPROM Electrical Erasable Programmable Read Only Memory. This equipment
component is used to record and store data that needs to be retained when the
equipment is powered down.
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 8kb/s.