Comtech EF Data VIPERSAT File Streamer v1.2.x User Manual

Page 47

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Appendix

A -

Glossary

A-3

E

E

b

/N

o

E

b

/N

o

is the ratio of E

b

(energy per bit) and N

o

(noise power density per Hz).

The bit error rate (BER) for digital data is a decreasing function of this ratio. E

b

is the energy of an information bit measured in Joules, or equivalently, in Watts

per Hertz.

F

FAST Code Fully Accessible System Topology Code – Designation for feature code used

by Comtech EF Data for their satellite modems. The FAST method makes it

easy to quickly upgrade the feature options of a modem while it is running live

in the network, either on site or remotely.

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.

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 VMS burst controller.

GUI Graphical User Interface – A form of graphical shell or user interface to a

computer operating system.

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