G
Gc
The interface between the GGSN and the HLR in a GSM/GPRS network
Gd
The interface between the SGSN and the SMSC in a GSM/GPRS network
Gf
The interface between the SGSN and the EIR in a GSM/GPRS network
Gi
The interface between the GGSN and the Internet in a GPRS network
Gn
The interface between the GGSN and the SGSN in a GPRS network
Gp
The interfaces between the GGSN/SGSN and the Border Gateway in a GPRS network
Gr
The interface between the SGSN and the HLR in a GPRS network
Gs
The interface between the SGSN and the MSC in a GSM/GPRS network
GAIT
GSM/ANSI 136 Interoperability Committee
GAP
Generic Access Profile; a DECT term
Gbit/s
A unit of data transmission rate equal to one billion bits per second
GMSC
Gateway Mobile Services Switching Centre; the gateway between two networks
GCF
Global Certification Forum
Geostationary
Refers to a satellite in equatorial orbit above the earth which appears from the surface to be stationary
GERAN
GSM-EDGE Radio Access Network; the name for the evolution of GSM towards 3G based on EDGE
GGRF
GSM Global Roaming Forum
GGSN
Gateway GPRS Support Node; the gateway between a cellular network and a IP network.
GHz
A unit of frequency equal to one billion Hertz per second
GMPCS
Global Mobile Personal Communications by Satellite
GMSK
Gaussian filtered Minimum Shift Keying; a refinement of FSK which minimises adjacent channel interference
GPRS
General Packet Radio Service; standardised as part of GSM Phase 2+, GPRS represents the first implementation of packet switching within GSM, which is a circuit switched technology. GPRS offers theoretical data speeds of up to 115kbit/s using multislot techniques. GPRS is an essential precursor for 3G as it introduces the packet switched core required for UMTS
GPS
Global Positioning System; a location system based on a constellation of US Department of Defence satellites. Depending on the number of satellites visible to the user can provide accuracies down to tens of metres. Now being incorporated as a key feature in an increasing number of handsets
GRX
GPRS Roaming Exchange
GSM
Global System for Mobile communications, the second generation digital technology originally developed for Europe but which now has in excess of 71 per cent of the world market. Initially developed for operation in the 900MHz band and subsequently modified for the 850, 1800 and 1900MHz bands. GSM originally stood for Groupe Speciale Mobile, the CEPT committee which began the GSM standardisation process
GSM MoU
The GSM Memorandum of Understanding, an agreement signed between all the major European operators to work together to promote GSM. The precursor of the GSM Association
GSM-R
GSM-Railway, A variant of GSM designed to meet the special communications needs of international train operators
