Personal Handy-phone System

Personal Handy-Phone System

The Personal Handy-phone System (PHS), also marketed as the Personal Access System (PAS), is a mobile network system operating in the 1880-1930 MHz frequency band.

Technology

PHS is, essentially, a cordless telephone with the capability to handover from one cell to another. PHS cells are small, with transmission power a maximum of 500mW and range typically measures in tens or at most hundreds of meters, as opposed to the multi-kilometer ranges of GSM. This makes PHS suitable for dense urban areas, but impractical for rural areas, and the small cell size also makes it difficult if not impossible to make calls from rapidly moving vehicles.

PHS uses TDMA/TDD as its radio interface and 32K ADPCM as its voice codec. Modern PHS phone can also support many value-added services such as high speed wireless Internet connection (32K/64K), Web access, emailing, text messaging and even color image transfer.

PHS technology is also a popular option for providing a wireless local loop, where it is used to bridge the "last mile" gap between the POTS wired network and the subscriber's home.