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cheekyangus · 24-06-2021, 14:37

I've come up with an alternative idea regarding what's happening with 5Select. It's unlikely though.

The information posted by Channel 5 says it's only going to be receivable on Freeview via equipment with an HD tuner, so the automatic thinking is BBCB/PSB3 or the temporary COM7 but that's not actually the only possibility.

In the UK our HD DTT multiplexes have all been DVB-T2 with MPEG4 streams carrying the HD and SD channels on them. However HD doesn't need to be MPEG4 and MPEG4 doesn't need to be DVB-T2. To my recollection Australia had (past tense) HD using MPEG2 and France used to have MPEG4 carried via DVB-T.

My point is that it that one of the current UK DVB-T multiplexes could carry an MPEG4 stream alongside the MPEG2 streams. A channel delivered this way would only be receivable by equipment with the ability to decode MPEG4, which in the UK would mean equipment that also happens to be DVB-T2. DVB-T2 equipment would decode the MPEG4 whether it is on T or T2.

Why would you want to carry MPEG4 on a DVB-T multiplex in the UK? Well it's a way of slowly transitioning services to better technology without switching the entire multiplex over and requiring all the channels on that multiplex to change at once.

There would be a gradual change, and one by one the entire multiplex will turn MPEG4. By the end you could simply upgrade the multiplex to DVB-T2 and benefit from the extra bandwidth from doing so, allowing more services or better quality transmission e.g. higher res SD or HD, or a mix of both.

DVB-T2 offers more bandwidth than DVB-T, it's not that HD or MPEG4 can't be delivered by the latter.

A mixed technology service has already been implemented in the UK, so it can be done. The main National 1 commercial DAB Radio multiplex has been carrying a mix of DAB and DAB+ for a few years now. Gradually more and more DAB+ stations have been added as the DAB stations have been removed. Old DAB equipment can see the DAB+ stations listed but not tune in, an incentive to upgrade but not rendering their existing equipment useless.

Maybe 5Select is remaining on COM4/SDN and simply this is the first of many channels to switch?

24-06-2021, 14:37	#124
cheekyangus cf.mega poster Join Date: Jan 2007 Posts: 2,526	Re: Freeview changes I've come up with an alternative idea regarding what's happening with 5Select. It's unlikely though. The information posted by Channel 5 says it's only going to be receivable on Freeview via equipment with an HD tuner, so the automatic thinking is BBCB/PSB3 or the temporary COM7 but that's not actually the only possibility. In the UK our HD DTT multiplexes have all been DVB-T2 with MPEG4 streams carrying the HD and SD channels on them. However HD doesn't need to be MPEG4 and MPEG4 doesn't need to be DVB-T2. To my recollection Australia had (past tense) HD using MPEG2 and France used to have MPEG4 carried via DVB-T. My point is that it that one of the current UK DVB-T multiplexes could carry an MPEG4 stream alongside the MPEG2 streams. A channel delivered this way would only be receivable by equipment with the ability to decode MPEG4, which in the UK would mean equipment that also happens to be DVB-T2. DVB-T2 equipment would decode the MPEG4 whether it is on T or T2. Why would you want to carry MPEG4 on a DVB-T multiplex in the UK? Well it's a way of slowly transitioning services to better technology without switching the entire multiplex over and requiring all the channels on that multiplex to change at once. There would be a gradual change, and one by one the entire multiplex will turn MPEG4. By the end you could simply upgrade the multiplex to DVB-T2 and benefit from the extra bandwidth from doing so, allowing more services or better quality transmission e.g. higher res SD or HD, or a mix of both. DVB-T2 offers more bandwidth than DVB-T, it's not that HD or MPEG4 can't be delivered by the latter. A mixed technology service has already been implemented in the UK, so it can be done. The main National 1 commercial DAB Radio multiplex has been carrying a mix of DAB and DAB+ for a few years now. Gradually more and more DAB+ stations have been added as the DAB stations have been removed. Old DAB equipment can see the DAB+ stations listed but not tune in, an incentive to upgrade but not rendering their existing equipment useless. Maybe 5Select is remaining on COM4/SDN and simply this is the first of many channels to switch? Last edited by cheekyangus; 24-06-2021 at 14:40.