The way I see it in the future (less then 10 years) they will go after 600MHz too pushing the TV channels lower, then they will go after 500MHz. The spectrum is to valuable a natural resource that it will be sold off in time to the Cell phone companies.
The other question you have to look at is ‘do we really need 51 channels for DTV?’ The answer is clearly no we do not. We have around digital 20+ OTA channels in the GTA… the amount of spectrum they also use could be cut in half, right now, if they were to switch over to MPEG-4, so in the future I’m sure they will be forced over to MPEG-4.
Another idea that comes to my mind when I think about all of this is… do we really need to be sending out Digital TV using one high power transmitter? What if we used a series on low power digital TV transmitters every few miles… the existing Cell phone towers could each be equipped with low power digital OTA ATSC transmitters forming their own cellular TV network. Since Digital TV already uses virtual channeling this would work very well allowing adjacent cells to use different RF channels. This would give great coverage to the end users… you would only need a small indoor antenna to receive the signal for a local cell tower. All you DTV channels would be coming from the one tower. This would also prevent Canadians from receiving American TV if they were also to switch to such a system… and we know our Government will like that idea.
The use of low power transmitters would also take care of any interference problems.
I’m sure in the next 20 years we’re going to see a big change in the way Digital TV is delivered OTA.