Radio-paging code No. 1

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.

In the 1990s new paging codes were developed that offered higher data transmission rates and other advanced features such as European and network roaming.

Faster transmission at 1200 or 2400 bits per second using so-called Super-POCSAG has mostly displaced the POCSAG in the developed world but the transition is still in progress.

The meetings were chaired by R.H.Tridgell and were attended by representatives of British, European, and Japanese pager manufacturers[1] The modulation used is frequency-shift keying (FSK) with a ±4.5 kHz shift on the carrier.

This strategy allows the receiver to turn off for a considerable percentage of the time as it only needs to listen to the pair that applies to it, thus saving a significant amount of battery power.

Values beyond 9 in each nibble (i.e. 0xA through 0xF) are encoded as follows: BCD messages are space padded with trailing 0xC's to fill the codeword.

There is no POCSAG specified restriction on message length, but particular pagers of course have a fixed number of characters in their display.

The side benefit of this is a slightly increased error-correcting code reliability for messages that span more than one POCSAG packet.

In the UK, most pager transmissions are in five bands at The frequency 466.075 MHz was previously used by Hutchison Paging, but the network was shut down in 2000.

It appears that US-specification paging systems operating on 27.255 MHz have been sold in Italy and other European countries.

In many areas in the United States, these frequencies are used for land mobile (two-way) radio communications services in addition to paging.

The VHF low band (35/43 MHz) frequencies are mainly used for local hospital paging and in many areas are completely unused.