total access communications system (mobile communications) (TACS)

Total Access Communications System (TACS) is a cellular analog mobile communications system based on Advanced Mobile Phone System( AMPS). It was deployed in Europe in the 900 MHzfrequency range and formed the transition from 1st generation( 1G) analog mobile communications networks to 2nd generation( 2G) cellular and digital mobile communications networks.

The frequency ranges of TACS are between 90 MHz and 915 MHz and between 935 MHz and 960 MHz. These are the frequency ranges that were later used for GSM. The channel width of TACS was 25 kHz, frequency modulation was used as the modulation method and Frequency Division Multiple Access( FDMA) as the access method. The Japanese variant of TACS was called JTACS and had an additional frequency band. In addition, there is a version developed in England, the Extended Total Access Communications System( ETACS), in which more radio channels can be allocated.