The digital version of the Advanced Mobile Phone Service (AMPS), the standard analog cellular phone technology common throughout North America and around the world. Digital Advanced Mobile Phone Service (D-AMPS) cellular systems, which have been used since 1992, build on the large installed base of AMPS cellular network installations.
D-AMPS is cheaper and easier to implement than Code Division Multiple Access (CDMA) cellular technologies, but its transmissions are not as secure.
D-AMPS uses the same 800 to 900–MHz frequency bands and 30-kHz carrier spacing that AMPS uses, although a dual-band 800/1900 MHz system has also been implemented.
D-AMPS differs from AMPS technology by using Time Division Multiple Access (TDMA) technology as its media access technique. TDMA splits each 30 kHz–wide AMPS channel into three additional channels.
This triples the number of cellular phone channels available under AMPS. D-AMPS is an easier upgrade path from AMPS than Global System for Mobile Communications (GSM), which also uses TDMA technology but in an incompatible format.