The lost origins of Video on Demand - and broadband
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For many years telecom laws protected the cable tv companies by prohibiting BT from broadcasting down its phone lines. In September 1993, after discussions with the DTI and Oftel, the Independent Television Commission said the Broadcasting Act 1990 would let BT use its network to provide Video on Demand.
VOD was classified as monocasting, not broadcasting, because each viewer can get what they want, when they want it.
The twisted pair copper wires which connect homes to BT's telephone network were designed to carry analogue speech. The 3.5 kHz bandwidth limits long distance modem communication to around 50 kilobits/second. But ADSL lets the wires carry the 2 megabits needed for video compressed to the MPEG-1 standard, for a few kilometres.
Asymmetric Digital Subscriber Loop was developed by BT, Bell Laboratories and Stanford University. It uses Discrete Multi-Tone modulation which splits the video payload into many separate data streams, typically 256. The raw video signal is piped by optic fibre to local exchanges and DMT coded for the last mile. Over 90% of homes were close enough to an exchange to receive 1.5 or 2 MBit/s.
BT tested delivery to a few homes near its Labs in Martlesham, and in 1995 started a one year full service trial for 2500 homes in Ipswich and Colchester. Movies were stored on a computer server and sent to homes on demand via individual coders and decoders. BT planned 400 servers across the country, delivering movies at around the same cost, L2.50, as tape rental.
In November 1996 BT promised to publish the results "in a few weeks". But there was no formal announcement. Informally BT said that viewers had been happy but the crippling cost of making them happy made a national service impractical. Elsewhere others were learning the same lesson.
As BT quietly shelved its plans for video on demand, Hull, in the North of England, was promising its own independent service. Hull's phones are independent from BT because in 1904 the British government offered local councils the chance to compete with the national Post Office service. Six tried but only the Hull Corporation remained independent.
Hull's arms-length telephone division, Kingston Communications, served 200,000 subscribers over a 120 sq mile area. Like BT, Kingston and Hull were banned from tv braodcasting. But they too saw the loophole in the 1990 Broadcasting Act which allows monocasting.
In 1996 Kingston ran a secret VOD trial using ADSL technology in 20 employees' homes for six months. This widened to 250 telephone subscribers, with a computer server at Kingston's exchange in Hessle storing movies for phone subscribers to watch.
Kingston reckoned it had a better better chance of making VOD cost-effective than BT. Hull had no cable tv system to compete with and because Kingston only operates in a tightly defined area, it knows the maximum number of subscribers its servers must serve. Like BT, Kingston insisted that the trial was a success. But no commercial VOD service was launched.
BT then changed tack and started using ADSL to provide subscribers with fast Internet access, instead of Video on Demand.
This was possible because Margaret Becket, then President of the Board of Trade, said Britain's telephone companies could start start broadcasting from 1 January 2001. There will then be no need for any telecoms companies to use the hugely expensive VOD loophole in the Broadcasting Act. A third British company tried to use VOD for something completely different, but has also quietly given up.
In May 1995, while the telephone companies were getting excited about Video on Demand, British Airways got excited too. For years all passengers had been obliged to watch the same movie on a cabin screen. Then there was a limited choice from tapes.
BA's idea was to fit a computer server on a 747 to deliver movies, news, shopping and gaming on demand to personal screens at all 400 seats. If the trial was a success, said BA, the airline would spend £80 million on equipping all 89 of its long haul planes with servers and 30 000 personal screens.
BE Aerospace of Florida was building the hardware and BT would provide satellite links to let BA debit passengers' credit cards while they flew. Each passenger was to be given a remote control which surfed through 24 channels of entertainment, the server allowing several passengers to watch the same programme at the same time, from different start times. Premium movies would need a credit card swipe.
BA wanted the US government's ban on inflight gambling lifted so that it could offer video roulette on demand, with passengers given the chance to win back the price of their ticket.
Sceptics pointed to the hardware cost of around £1 m a plane, the weight of the server and the risk of angering pasengers if the computer crashed and left everyone with blank screens or error messages.
But Emma Horrill, BA's Executive in charge of Interactive Video, insisted "We believe the system will transform inflight entertainment". She said the VOD trial plane was going to work for three months on routes in the Far East, US and Africa.
The results of the trial were never announced.
But now the world has caught up. ADSL has made broadband a way of life and long haul airlines all offer VOD.