G

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Gain

All antennas possess a figure of merit called "gain." Gain is measured by comparing the performance of a given antenna to a theoretical ideal antenna—the isotropic antenna which has a gain of 0 dB. Thus, gain is measured in dBi—the "dB" portion stands for decibels and the "i" stands for isotropic. Gain is important to antenna selection because, all other things being equal, the antenna with the higher gain figure will have the better performance.

Gateway

In a network the term generally refers to an electronic repeater device that intercepts and steers electrical signals from one network to another. Thus a gateway device provides the entrance and/or exit paths to and from a communications network. A typical gateway is a combination of hardware and software; the hardware device (typically a "bridge") and the software work in tandem to perform the necessary translations to allow traffic to flow smoothly between networks.

General Packet Radio Service (GPRS)

A radio technology for GSM networks that adds packet-switching protocols. As a 2.5G technology, GPRS enables high-speed wireless Internet and other data communications. GPRS networks can deliver Short Message Service (SMS), Multimedia Message Service (MMS), email, games, etc.

See also 2.5G.

Gigahertz (GHz)

The international unit for measuring frequency is hertz (Hz), which is equivalent to cycles per second. A gigahertz is a unit of frequency that is equal to one billion hertz or cycles per second.

GPRS

See General Packet Radio Service (GPRS).

GSM

Originally the acronym stood for Groupe Speciale Mobile, but it has been anglicized to "Global System for Mobile Communications," an international digital cellular standard, although it is more widely used in Europe than elsewhere.

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