Teletext and to pad out the fixed packet. The vertical caption position is determined by the packet address. In the case of the Ceefax and ORACLE systems and their successors in the UK, the teletext signal is transmitted as part of the ordinary analog TV signal but concealed from view in the Vertical Blanking Interval (VBI) television lines which do not carry picture information. The teletext signal is digitally coded as 45-byte packets, so the resulting rate is 7,175 bits per second per used lines (41 7-bit 'bytes' per line, on each of 25 frames per second). A teletext page comprises
BBC World Service Television BBC World Service Television BBC World Service Television, often abbreviated to WSTV (World Service Television), was the name of two BBC international satellite television channels between 1991 and 1995. It was the BBC's first foray into worldwide television broadcasting. In Europe, it was the successor to BBC TV Europe, which it replaced on 11 March 1991. The service was also launched in Asia as a 24-hour news and information service with minor differences, a precursor to BBC World News, launched on 14 October 1991. Unlike the BBC World Service at the time, it was not funded by the British government