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Thomas Haug (first GSM president) and Philippe Dupuis (second GSM president) during a GSM meeting in Belgium, April 1992. In 1983, work began to develop a European standard for digital cellular voice telecommunications when the European Conference of Postal and Telecommunications Administrations (CEPT) set up the Groupe Spécial Mobile (GSM) committee and later provided a permanent technical ...
GSM is a standard for mobile phones.The ubiquity of the GSM standard makes international roaming very common with "roaming agreements" between operators. GSM differs significantly from its predecessors, in that both signalling and speech channels are digital, which means that it is seen as a second generation mobile phone system.
The GSM standards are defined by the 3GPP collaboration and implemented in hardware and software by equipment manufacturers and mobile phone operators. The common standard makes it possible to use the same phones with different companies' services, or even roam into different countries. GSM is the world's predominant mobile phone standard.
GSM 900 (900 MHz) is suitable for light urban coverage. GSM 1800 (1.8 GHz) starts to be limited by structural walls. UMTS, at 2.1 GHz is quite similar in coverage to GSM 1800. Higher frequencies are a disadvantage when it comes to coverage, but it is a decided advantage when it comes to capacity.
GSM uses TDMA and FDMA for user and cell separation. UMTS, IS-95 and CDMA-2000 use CDMA. WiMAX and LTE use OFDM. Time-division multiple access (TDMA) provides multiuser access by chopping up the channel into sequential time slices. Each user of the channel takes turns to transmit and receive signals.
Most 2G cellular systems, with the notable exception of IS-95, are based on TDMA. GSM, D-AMPS, PDC, iDEN, and PHS are examples of TDMA cellular systems.. In the GSM system, the synchronization of the mobile phones is achieved by sending timing advance commands from the base station which instruct the mobile phone to transmit earlier and by how much.
GSM, or grams per square meter, measures the weight and feel of a fabric. We spoke with experts about the difference between GSM and thread count and how to look for high quality towels.
Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations.