Independent Television in the United Kingdom can be split into three distinct periods - 1955-1968, 1968-1992 and 1993 onwards. The first, from foundation in 1955 until the first big contract changes in 1968, could broadly be called 'the age of the mosaic'.
When Sir Kenneth Clark and his Authority sat down in 1954 to first decide on how the new network would operate, they had several choices. The Television Act insisted that they not only provide competition for the BBC, but also have competition built into the system itself.
The first possible option was that of appointing two contractors for each transmitter. That way, each company would have direct, regulated competition for its programme service from day one.
The flaw in this proposal was the lack of frequencies in VHF Band III. The available frequencies were enough to cover most, if not all, of the country with one frequency used in each area. If two frequencies were used, the 'jigsaw' pattern, where no two stations with an adjoining area could use the same frequency, would mean certainly less than a half, if not only a quarter, of the landmass could be covered. By implication, this proposal would actually limit competition rather than promote it.
A second way of dividing up the cake was 'horizontal' division. This would allocate certain programming strands and times to each company, so that TVA would operate between 10am and 2pm showing women's programmes, TVB would take over and run from 2pm to 6pm with, say, children's programming, TVC from 6pm to 10pm with entertainment etc. Each company would broadcast across all transmitters.
This idea was also impractical, as the competition was implied rather than real. Each company could have settled down to making the programmes appropriate to its timeslots, thus suiting advertisers who would buy space within each market exactly as they did between magazines on different subjects depending on who they wished to reach with their product.
The third proposal involved a 'vertical' split. Four or five companies would each be given two consecutive days a week. TVA could start with Monday and Tuesday, TVB with Wednesday and Thursday, TVC with Friday and Saturday, TVD with Sunday and Monday, then back to TVA for Tuesday and Wednesday, and so on.
The Authority thought this latter option provided the most competition of all three proposals, but that it would also be 'dizzying' - leaving viewers (not to mention the ITA) reaching for their calendars to discover exactly when TVB would next be on air and thus their favourite programme.
A simple 'one transmitter-one company' idea didn't allow for competition, so a compromise idea was adopted, where the three largest regions have two companies, one operating at weekends, one on weekdays - the most logical split.
However, this idea created six companies - far more than the profits of the new network could ever hope to carry, it was thought. Therefore, the companies would have to share, to try to create a system where each was roughly equal in size. It was felt that North weekdays and London weekdays were both large enough and self-contained. The weekends were not large enough to sustain an independent programme company, and neither was the Midlands weekdays area.
So London weekends were tied to Midlands weekdays, creating a company that it was thought would be equal to the two weekday-only companies. This left the north and midlands weekends, the joining together of which would create a region capable of supporting a fourth company.
The final part of the idea was what to do with the smaller transmitter areas that would come later to 'fill in the gaps' and take the network national. The Authority decided that each of these transmitters would have one company, and each company would be a new entrant. They would be seven-day companies, with a remit to provide a local service and purchase network programmes from the Big Four, creating an additional level of competition. Their opportunities to 'upload' to the network would be limited, a tiny percentage of the time available each year, with an eye to forcing them to specialise in programme for their own area.
The system was not without some drawbacks. It prevented London dominating the network, but the 4 main companies built (or already owned) studios in London anyway. The system allowed northern and midlands culture to appear on screen for the rest of the country to view - but prevented, say, Cornish or Geordie culture doing the same.
But from one point of view, the system was a great success. With the exception of the very smallest stations (Border, Channel and Teledu Cymru), the companies enfranchised by the ITA at the start soon became thunderously rich beyond the dreams of avarice.