Hitachi HANDYTONE-486 - Manual (Page 40)

HandyTone-486 User Manual Grandstream Networks, Inc.
40
9 Glossary of Terms
ADSL
Asymmetric Digital Subscriber Line: Modems attached to twisted pair copper wiring that
transmit from 1.5 Mbps to 9 Mbps downstream (to the subscriber) and from 16 kbps to 800
kbps upstream, depending on line distance.
AGC
Automatic Gain Control, is an
electronic system found in many types of devices. Its purpose is
to control the gain of a system in order to maintain some measure of performance over a
changing range of real world conditions.
ARP
Address Resolution Protocol is a protocol used by the Internet Protocol (IP) [ RFC826] ,
pecifically IPv4, to map IP network addresses to the hardware addresses used by a data link
protocol. The protocol operates below the network layer as a part of the interface between the
OSI network and OSI link layer. It is used when
IPv4 is used over Ethernet
ATA
Analogue Telephone Adapter. Covert analogue telephone to be used in data network for VoIP,
like Grandstream HT series products.
CODEC
Abbreviation for Coder-Decoder. It's an analog-to-digital (A/D) and digital-to-analog (D/A)
converter for translating the signals from the outside world to digital, and back again.
CNG
Comfort Noise Generator, geneate artificial background noise used in radio and wireless
communications to fill the silent time in a transmission resulting from voice activity detection .
DATAGRAM
A data packet carrying its own address information so it can be independently routed from its
source to the destination computer
DECIMATE
To discard portions of a signal in order to reduce the amount of information to be encoded or
compressed. Lossy compression algorithms ordinarily decimate while subsampling.
DECT
Digital Enhanced Cordless Telecommunications: A standard developed by the European
Telecommunication Standard Institute from 1988, governing pan-European digital mobile
telephony. DECT covers wireless PBXs, telepoint, residential cordless telephones, wireless
access to the public switched telephone network, Closed User Groups (CUGs), Local Area
Networks, and wireless local loop. The DECT Common Interface radio standard is a
multicarrier time division multiple access, time division duplex (MC-TDMA-TDD) radio
transmission technique using ten radio frequency channels from 1880 to 1930 MHz, each
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