personal access communications system (mobile communications) (PACS)

Personal Access Communications System (PACS) is a digital cellular mobile radio system that was developed as early as the mid-1980s and standardized by ANSI in the 1990s.

Conceptually, a PACS network is a cellular access network for voice transmission based on microcells. The cell diameter is about 300 meters. PACS has roaming and uses the TDMA method with eight time slots per frequency. PACS used in the U.S. has its transmission frequencies between 1.92 GHz and 1.93 GHz. Designed as a wireless access network, PACS provides circuit-switched and packet-switched interfaces to the user. Services supported include analog and digital voice, fax and X.25.

The PACS network consists of the handset, the Subscriber Unit(SU), the Radio Port( RP), the Controller Station( RPC) and the Access Manager( AM).