digital advanced mobile phone system (mobile communications) (D-AMPS)

The U.S. mobile communications system D- AMPS(Digital Advanced Mobile Phone System) is based on the analog AMPS system.

Unlike the analog AMPS, the 30 kHz channels of the digital AMPS are divided into three digital channels which are transmitted using the TDMA method. D-AMPS uses a wide variety of coding techniques to achieve the highest possible transmission rate per channel.

The original D-AMPS standard was specified in IS-54, which was later incorporated in the IS standard IS-136. ANSI-136/IS-136 used the 850 MHz band and the 1,900 MHz band. The standards supported voice and data services with data rates up to 8 kbit/s and the Short Message Service( SMS).