What happens to the old analog spectrum space now that all TV is broadcast in the digital spectrum space?
- ChrisLv 67 years agoFavorite Answer
It's still used for Digital.
In the UK, the analogue TV spectrum ran from Ch21 to Ch68. The frequency spread was roughly 470 MHz to 850 MHz. Straight away you've probably spotted that that provides 47 channel numbers but there was nothing like 47 channels on the old analogue system. There were 5 as a maximum. The reason for that was to provide individual transmitters their own channel space. This meant that in areas where two TV regions overlapped that the TV would be able to discriminate between say Tyne Tees and Yorkshire, or Yorkshire and Granada etc.
For a while Digital TV co-existed in the same channel space. Ofcom and the Broadcasting Industry worked out a way to re-jig the channels to accommodate both analogue and digital with the minimum amount of disruption so that consumers had time to equip with new digital-compatible TVs and set top boxes. Once the tipping point arrived then the UK began the process of digital switch-over.
Digital TV works in the same channel space that analogue used to inhabit (Ch 21-68). The difference is that the digital service packages several channels in a data stream called a MUX (multiplex) where analogue could only cater for one. There are now seven digital multiplexes used to deliver all the channels that the UK Freeview TV service can provide.
About 18 months ago the UK Government sold off a portion of the UK TV channel spectrum to the mobile phone industry to cater for 4G. As a result the UK TV spectrum now runs from Channel 21 through to Ch 60 inclusive.
So to recap, digital uses the same channel range as analogue did, but it works in a slightly different way which explains why there's so many more channels.
- Anonymous7 years ago
Interesting question. I had to look this up and found the following:
"In addition to white space assigned for technical reasons, there is also unused radio spectrum which has either never been used, or is becoming free as a result of technical changes. In particular, the switchover to digital television frees up large areas between about 50 MHz and 700 MHz. This is because digital transmissions can be packed into adjacent channels, while analog ones cannot. This means that the band can be "compressed" into fewer channels, while still allowing for more transmissions."
So basically, the previously analog space is just being recycled into digital space according to this write-up. It goes on to say that some of the upper frequencies are just being left as white space and other technologies are now being adapted to use those frequencies such as internet connectivity.
- 7 years ago
It gets donated to the homeless.