You may be interested in this.
http://www.rediffusion.info/
We had a modern offshoot of it in Hemel Hempstead. The new town was built with the concept of "NO AERIALS" with TV/Radio services provided by British Relay.
The system used a multi-core cable to provide 4 TV & 4 Radio channels. BBC 1 & ITV London were provided, along with BBC 2 & ITV Anglia (until the launch of Channel 4), & BBC Radios 1, 2, 3 & 4. With the cabling going from house to house & being subsidised by the local council it managed to last until the end of 1982, when the plug was pulled.
We then had to wait until 1990 for County Cable to start installing HFC. For a while they too provided us with Anglia ITV & the first local TV channel in the country (West Herts Television). The local TV service closed when Comtel took over from Telecential, & ITV Anglia disappeared (to much local disgust) when services went digital.