POCSAG

Radio-paging code No. 1 (usually and hereafter called POCSAG) is an asynchronous protocol used to transmit data to pagers such as alphanumeric pagers and numeric pagers. Its usual designation is an acronym of the Post Office Code Standardisation Advisory Group, the name of the group that developed the code under the chairmanship of the British Post Office that used to operate most telecommunications in Britain before privatization. Before the development and adoption of the POCSAG code, pagers used one of several codes such as binary Golay code. In the 1990s new paging codes were developed that offered higher data transmission rates and other advanced features such as European and network roaming. The POCSAG code originally transmitted at 512 bits per second. Faster transmission at 1200 or 2400 bits per second using so-called Super-POCSAG has largely displaced the slower, original POCSAG in the developed world, although the faster "Super-POCSAG" has not yet entirely replaced standard POCSAG as of 2011.