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
Teletext economic Teletext system with 1971 technology. However, as low cost was essential to the project's long term success, this obstacle had to be overcome. Meanwhile, the General Post Office (GPO), whose telecommunications division later became British Telecom, had been researching a similar concept since the late 1960s, known as Viewdata. Unlike Teledata which was a one-way service carried in the existing TV signal, Viewdata was a two-way system using telephones. Since the Post Office owned the telephones, this was considered to be an excellent way to drive more customers to use the phones. In 1972 the BBC demonstrated their system,