User guide

I-4 VMS User Guide
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 or software application.
H
HDLC High Level Data Link Control – A standard defining how data may be transmit-
ted down a synchronous serial link.
HPA High Power Amplifier – The amplifier used in satellite communications to raise
the transmit signal to the correct power level prior to transmission to satellite.
HTTP Hyper Text Transfer Protocol – The Internet standard for World Wide Web
(WWW) operation.
Hub The central site of a network which links to a number of satellite earth sites
(remote’s).
I
ICMP Internet Control Message Protocol
IF Intermediate Frequency – In satellite systems, IF frequencies are usually
centered around 70 or 140 MHz (video/TV), or 1200 MHz (L-band).
IP Internet Protocol – A format for data packets used on networks accessing the
Internet.
ISP Internet Service Provider – A company providing Internet access.
ITU International Telecommunications Union