BBC teletext service, Ceefax, was introduced, created initially to provide subtitling, but developed into a news and information service. In 1978, BBC staff went on strike just before the Christmas of that year, thus blocking out the transmission of both channels and amalgamating all four radio stations into one. Since the deregulation of the UK television and radio market in the 1980s, the BBC has faced increased competition from the commercial sector (and from the advertiser-funded public service broadcaster Channel 4), especially on satellite television, cable television, and digital television services. In the late 1980s, the BBC began a process of
BBC news and sport station. In 1997, BBC News 24, a rolling news channel, launched on digital television services and the following year, BBC Choice launched as the third general entertainment channel from the BBC. The BBC also purchased The Parliamentary Channel, which was renamed BBC Parliament. In 1999, BBC Knowledge launched as a multi media channel, with services available on the newly launched BBC Text digital teletext service, and on BBC Online. The channel had an educational aim, which was modified later on in its life to offer documentaries. In 2002, several television and radio channels were reorganised. BBC Knowledge