GSM and GSM 900 and GSM 1800

GSM:- Global System for Mobile, an international standard for mobile phones

GSM-900 and GSM-1800 are used in most parts of the world: Europe, Middle East, Africa and most of Asia.

* GSM-900 uses 890 - 915 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and 935 - 960 MHz for the other direction (downlink), providing 124 RF channels (channel numbers 1 to 124) spaced at 200 kHz. Duplex spacing of 45 MHz is used.

In some countries the GSM-900 band has been extended to cover a larger frequency range. This 'extended GSM', E-GSM, uses frequency range 880 - 915 MHz (uplink) and 925 - 960 MHz (downlink), adding 50 channels (channel numbers 975 to 1023 and 0) to the original GSM-900 band. The GSM specifications also describe 'railways GSM', GSM-R, which uses frequency range 876 - 915 MHz (uplink) and 921 - 960 MHz (downlink). Channel numbers 955 to 1023. GSM-R provides additional channels and specialized services for use by railway personnel.

All these variants are included in the GSM-900 specification.

* GSM-1800 uses 1710 - 1785 MHz to send information from the Mobile Station to the Base Transceiver Station (uplink) and 1805 - 1880 MHz for the other direction (downlink), providing 374 channels (channel numbers 512 to 885). Duplex spacing is 95 MHz.

GSM-1800 is also called PCS in Hong Kong and the United Kingdom. Most of the GSM operators in India use the 900 MHz band. Operators like , Airtel, Idea, and some others, use 900MHz in rural areas as well as in urban areas.where as hutch uses 1800mhz everywhere except in its bpl network

NelsonJosepha at 2007-7-12 8:17:08 >