Audio coding and compression at 48-64 Kbps, 3 Khz (telephone quality)

Audio coding and compression at 48-64 Kbps, 7 Khz

Audio coding and compression at 5.3 to 6.3 Kbps, for lowest bandwidth calls

Audio coding at 40, 32, 24, and 16 Kbps utilising Adaptive Differential Pulse Code Modulation (ADPCM)

Audio coding and compression at 16 Kbps, for low bandwidth calls; can be a-law or u-law

Audio coding and compression at 8 Kbps, for low bandwidth calls

GSM Ansi-136 Interoperability Team

Generic Access Profile

Gatekeeper Synchronization Protocol

Telecommunications: H.323 entity on a LAN that provides address translation and control access to the LAN for H.323 terminals and gateways. The gatekeeper can provide other services to the H.323 terminals and gateways, such as bandwidth management and locating gateways. A gatekeeper maintains a registry of devices in the multimedia network. The devices register with the gatekeeper at startup and request admission to a call from the gatekeeper.

Gateways are points of entrance to and exit from a communications network. Viewed as a physical entity, a gateway is that node that translates between two otherwise incompatible networks or network segments. Gateways perform code and protocol conversion to facilitate traffic between data highways of differing architecture. In OSI terms, a gateway is a device that provides mapping at all seven layers of the OSI model. A gateway can be thought of as a function within a system that enables communications with the outside world.

Gigabyte

Approximately 1,000,000,000 bytes.

Gigabit

Approximately 1,000,000,000 bits.

Gigabytes Per Second

Gigabits Per Second

Generic Connection Admission Control

In ATM, a PNNI algorithm designed for CBR and VBR connections. Any node can use GCAC to calculate the expected CAC behaviour of another node given than node's advertised link metrics and the QoS of a connection setup request.

Generic Cell Rate Algorithm

In ATM, an algorithm that defines conformance with respect to the traffic contract of the connection. For each cell arrival, the GCRA determines whether the cell conforms to the traffic contract.

Gigabit Ethernet Alliance

Global European Network

BT, Deutsche Telekom, France Telecom, Telecom Italia and Telefonica were the originators of this fibre optic network to connect the capitals of their respective countries.

Geostationary Earth Orbit

Gateway-to-Gateway Protocol

MILNET protocol specifying how core routers (gateways) should exchange reachability and routing information. GGP uses a distributed shortest-path algorithm.

Gateway GPRS Support

Gigahertz

Global Interoperability of Broadband Networks

Geographical Information System

Global Internet eXchange

Common routing exchange point which allows pairs of networks to implement agreed-upon routing policies. The GIX is intended to allow maximum connectivity to the Internet for networks all over the world.

Global Maritime Distress & Safety System

Get Nearest Server

Request packet sent by a client on an IPX network to locate the nearest active server of a particular type. An IPX network client issues a GNS request to solicit either a direct response from a connected server or a response from a router that tells it where on the internetwork the service can be located. GNS is part of the IPX SAP.

Generally referring to the measurement of actual data successfully transmitted from the sender(s) to receiver(s). This is often a more useful measurement than the number of ATM cells per second throughput of an ATM switch if that switch is experiencing cell loss that results in many incomplete, and therefore unusable, frames arriving at the recipient.

Distributed document delivery system. The Internet Gopher allows a neophyte user to access various types of data residing on multiple hosts in a seamless fashion.

Grade of Service

Measure of telephone service quality based on the probability that a call will encounter a busy signal during the busiest hours of the day.

General Packet Radio Service

Part of the GSM Phase 2+ development and offers packet switching within GSM, enabling users to send and receive data at speeds up to 115kbit/s over a permanent connection when required.

Global Positioning Satellite/Global Positioning System

A system that uses radio signals between a vessel or vehicle on Earth to pinpoint the location of the vehicle or vessel.

Generic Routing Encapsulation

The process of separating and segregating telecommunications channels, as by combing, such that the broadest channel possible can be assembled and sent across the longest practical link. The aim is to minimize de-multiplexing traffic and reshuffling it electrically.

Collection of communications equipment designed to receive signals from (and usually transmit signals to) satellites.

Global System for Mobile Communications

Formerly stood for Groupe Spéciale Mobile. Digital cellular telephone standard.

Global Service Management Platform

GPRS Support Node

Geostationary Satellite Orbit

Generic Service State

General Switched Telephone Network

Unused frequency band between two communications channels that provides separation of the channels to prevent mutual interference.

Graphical User Interface

User environment that uses pictorial as well as textual representations of the input and output of applications and the hierarchical or other data structure in which information is stored. Conventions such as buttons, icons, and windows are typical, and many actions are performed using a pointing device (such as a mouse). Microsoft Windows and the Apple Macintosh are prominent examples of platforms using a GUI.