GSM stand for Global System for Mobile communications.It is a digital network that allows mobile phones users communicate over the air interface through frequency spectrum. Unlike the traditional PSTN (Public Switch Telephone Network) which requires copper wire connection from the telephone switching office to a telephone handset at your home or office, GSM technology doesnt needs copper wires.
GSM Frequency System: There is P-GSM 900 where P stands for Primary. It was the first system developed with a bandwidth of 25MHz. There is also E-GSM 900 where E stands for Extended, due to the limited bandwidth capacity of the P-GSM 900. The P-GSM was extended by 10MHz, therefore the E-GSM 900 has a bandwidth capacity of 35MHz.
Then there is GSM 1800 which has a bigger bandwidth of 75MHz and the last is GSM 1900 with a bandwidth of 60MHz.
Allocation of GSM Frequencies to Mobile Operators. Assignment and allocation of frequencies to mobile operators is the sole responsibility of the National Telecommunications Regulator. GSM frequencies are assign to each Telecom operator according to availability of the bandwidth and operator's bandwidth requirements. Where the number of operators are more, the regulators may decide to re-assign or allocate the frequencies to enable all operators operate the service.
FigA: GSM Frequency Spectrum, bandwidth, Carrier, No of radio channels per bandwidth.
