Cable Forum - View Single Post - Some thoughts on possible future Freeview capacity usage at MPEG4 switchover

cheekyangus · 06-04-2019, 19:37

The following is basically me thinking about how MPEG4 switchover on Freeview might look. The end state, not the process. It is very appropriate, based on some rough mental arithmetic and some assumptions.

- Based on the current PSB3 HD multiplex on Freeview you can get 6x 24hr HD channels + 1 SD channel. However on Cable, Virgin Media have between 7 and 8 HD channels per multiplex, usually 7. So there's potential for more. For this we will average it out and say a HD-only Freeview multiplex has a potential 7 HD channels.

- An SD-only multiplex, based on the current D3&4 multiplex with full SD resolution has room for 12 full resolution (i.e 720x576) SD channels on one multiplex at the current MPEG2.

- An SD-only multiplex, based on Cable example on Virgin Media, has 24-25 channels on one multiplex with MPEG4.

- 4 SD channels tend to fit into the space of 1 HD channel, so that would be 28 SD channels based on the HD, but let's assume that Cable, with less capacity constraints, has found 24 works best and go with that for a SD-only multiplex.

-Based on articles I've read the plan is apparently to reduce the current 6 national multiplexes (I'm excluding the 2 temporary HD muxes and the Local ones) down to 5, to clear the way for mobile phone data, so all my ideas are based on there being a reduced number of multiplexes.

- Given 3 of the current main multiplexes have only 80(?) sites (covering 90% population) and the other 3 have 1000+ (covering 98% population) I'm assuming the expense of upgrading 1000s will be mean that the multiplex that won't be upgraded to MPEG4 will be one of the PSB multiplexes that have thousands of sites. One of the 3 PSB muxes is MPEG4 already, so one one more multiplex needs upgraded.

- Apparently it is cheaper and better to have all the regional services on as few multiplexes as possible. It should be possible to have them all on one, the suggested multiplexes I will outline will be based on this.

- I'm assuming that money will form a large part of the reasoning behind the planning for MPEG4 switchover so a large part of my suggestions will be based on this.

First of all I think the current MPEG4 (PSB3) multiplex will remain virtually unchanged.

BBC1 HD
BBC2 HD
ITV/STV/UTV HD
Channel 4 HD
Channel 5 HD
CBBC HD (until 9pm everywhere but Scotland where BBC Scotland HD takes over at 7pm)

The change based on More4+1 removal and potential extra space based on Cable example:
BBC Parliament (SD)
BBC Red Button 1 (SD)
ITV/STV/UTV+1 (SD)
Channel4+1 (SD)
BBC Radio (Various)

These last 3 are based on there being a regional element (C4 is advertising, not programming). Parliament, RB1 and national radio are the most likely of these not to be on this mux, space/tech limiting.

One of the two other 2 PSB muxes will be upgraded to MPEG4. I think it would contain.
BBC News HD
Cbeebies HD/BBC4 HD
And then 16 SD channels from current D3&4 PSB Mux + related ones.
ITV2 & +1
ITV3 & +1
ITV4 & +1
ITVBe
CITV

E4 & +1
More4 +1
Film4 +1
4Music
4Seven

Because one PSB multiplex won't be upgraded to MPEG4, the assumption is that the existing remaining MPEG2 multiplex would be switched off.

My idea is that it would only be switched off at the main 80 locations that cover 90% of the population. The 1000s of sites that cover the remaining 8% could have it remain on, as MPEG2 and transmit at least 12 TV channels that are found on the upgraded non-PSB multiplexes to the other 90%. It would be like an SDN-lite, to give those in relay transmitter areas a little more selection and save money decommissioning that multiplex at all those sites.

Anyway, this is all just a rough idea. Feel free to have fun poking holes in it... it'll probably be easy.

06-04-2019, 19:37	#1
cheekyangus cf.mega poster Join Date: Jan 2007 Posts: 2,526	Some thoughts on possible future Freeview capacity usage at MPEG4 switchover The following is basically me thinking about how MPEG4 switchover on Freeview might look. The end state, not the process. It is very appropriate, based on some rough mental arithmetic and some assumptions. - Based on the current PSB3 HD multiplex on Freeview you can get 6x 24hr HD channels + 1 SD channel. However on Cable, Virgin Media have between 7 and 8 HD channels per multiplex, usually 7. So there's potential for more. For this we will average it out and say a HD-only Freeview multiplex has a potential 7 HD channels. - An SD-only multiplex, based on the current D3&4 multiplex with full SD resolution has room for 12 full resolution (i.e 720x576) SD channels on one multiplex at the current MPEG2. - An SD-only multiplex, based on Cable example on Virgin Media, has 24-25 channels on one multiplex with MPEG4. - 4 SD channels tend to fit into the space of 1 HD channel, so that would be 28 SD channels based on the HD, but let's assume that Cable, with less capacity constraints, has found 24 works best and go with that for a SD-only multiplex. -Based on articles I've read the plan is apparently to reduce the current 6 national multiplexes (I'm excluding the 2 temporary HD muxes and the Local ones) down to 5, to clear the way for mobile phone data, so all my ideas are based on there being a reduced number of multiplexes. - Given 3 of the current main multiplexes have only 80(?) sites (covering 90% population) and the other 3 have 1000+ (covering 98% population) I'm assuming the expense of upgrading 1000s will be mean that the multiplex that won't be upgraded to MPEG4 will be one of the PSB multiplexes that have thousands of sites. One of the 3 PSB muxes is MPEG4 already, so one one more multiplex needs upgraded. - Apparently it is cheaper and better to have all the regional services on as few multiplexes as possible. It should be possible to have them all on one, the suggested multiplexes I will outline will be based on this. - I'm assuming that money will form a large part of the reasoning behind the planning for MPEG4 switchover so a large part of my suggestions will be based on this. First of all I think the current MPEG4 (PSB3) multiplex will remain virtually unchanged. BBC1 HD BBC2 HD ITV/STV/UTV HD Channel 4 HD Channel 5 HD CBBC HD (until 9pm everywhere but Scotland where BBC Scotland HD takes over at 7pm) The change based on More4+1 removal and potential extra space based on Cable example: BBC Parliament (SD) BBC Red Button 1 (SD) ITV/STV/UTV+1 (SD) Channel4+1 (SD) BBC Radio (Various) These last 3 are based on there being a regional element (C4 is advertising, not programming). Parliament, RB1 and national radio are the most likely of these not to be on this mux, space/tech limiting. One of the two other 2 PSB muxes will be upgraded to MPEG4. I think it would contain. BBC News HD Cbeebies HD/BBC4 HD And then 16 SD channels from current D3&4 PSB Mux + related ones. ITV2 & +1 ITV3 & +1 ITV4 & +1 ITVBe CITV E4 & +1 More4 +1 Film4 +1 4Music 4Seven Because one PSB multiplex won't be upgraded to MPEG4, the assumption is that the existing remaining MPEG2 multiplex would be switched off. My idea is that it would only be switched off at the main 80 locations that cover 90% of the population. The 1000s of sites that cover the remaining 8% could have it remain on, as MPEG2 and transmit at least 12 TV channels that are found on the upgraded non-PSB multiplexes to the other 90%. It would be like an SDN-lite, to give those in relay transmitter areas a little more selection and save money decommissioning that multiplex at all those sites. Anyway, this is all just a rough idea. Feel free to have fun poking holes in it... it'll probably be easy.