I still predict that 27.5W will be turned off sooner or later.
1) there is enough backup capacity at 28E for one bird to fail completely and the major channels to be switched over to one of the other birds. It might take some major swapping around of frequencies but whatever disaster recovery plans SES have will have just this scenario in them.
2) BBC funding is reducing rapidly and 27.5W is a luxury when 28E is resilent enough to be used instead
3) Fibre penetration is improving all the time and lets be honest - short of the local farmer sticking his backhoe through the cable its pretty robust
Ergo slew the relay receive dishes round to 28E & shut the Intelsat uplink down
It wouldn’t be possible to use the existing feeds on 28.2°E though.
The way this system works is that the channels on 27.5°W are encoded in such a way that they can be piped into the digital terrestrial modulators at the transmitters when the main feed fails without any re-encoding of the data.
The maximum bitrate of the Freeview SD multiplex is around 24Mbps. All of the SD channels + radio stations, including one of the 4 BBC One SD versions, will never have a combined data rate of more than that 24Mbps. The Freeview HD multiplex has a maximum bitrate of around 40Mbps, and sure enough - the HD channels combined from 27.5°W never exceed this data rate.
You’d need another transponder in exactly the same way as 27.5°W currently works if you were to move it all over to 28.2°E. Presumably capacity on 27.5°W is cheaper!
Basically -
Using 1 transponder with all the channels packaged ready for digital terrestrial transmission (a la 27.5°W) = pretty cost effective
Receiving the various required channels from a number of different transponders, re-encoding them to match the different bitrate constraints and reassambling them into the two digital terrestrial multiplexes (if using the current 28.2°E feeds) = complex and expensive and on top of that the picture quality would be dreadful.
Granted, fibre is getting cheaper, but these are used as a backup at some of the most isolated transmitter sites.
It’s all a similar concept to the multistream transponders used to feed Italian/French/etc digital terrestrial - the data is all in the right format for digital terrestrial already. All the transmitter has to do is modulate a terrestrial signal without touching the programme (video, audio, EPG, etc) data at all.