Programme Identification (PI) is a service provided by
radio stations
transmitting
Radio Data System (RDS) data as part of the
FM radio
FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is cap ...
broadcast
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. Broadcasting began ...
. The PI code allows the radio to identify the station across different
broadcast relay stations. This in turn allows listeners to stay tuned to a network whilst travelling across the service area of multiple
transmitters.
The PI code is a 4-digit
hexadecimal
In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexa ...
(
16-bit
16-bit microcomputers are microcomputers that use 16-bit microprocessors.
A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...
) number. For example
BBC Radio 1 has PI code
C201. (The number itself is usually not displayed on radio receivers.)
PI codes are
not globally unique; ranges are assigned per-country, and are re-used in countries beyond FM radio range of each other. For example, the first digit "C" as used in the BBC PI code example is used by the
United Kingdom,
Lithuania
Lithuania (; lt, Lietuva ), officially the Republic of Lithuania ( lt, Lietuvos Respublika, links=no ), is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea. Lithuania ...
,
Croatia, and
Malta.
They can be made globally unique by combining them with an ECC (extended country code).
PI codes are also used in
Digital Audio Broadcasting as Station ID, and by the
RadioDNS standard.
References
{{DEFAULTSORT:Programme Identification
Radio technology