BBC HD on Freeview proposal

The BBC has 2 multiplexes with a total of 36.2 Mbps of capacity at its
disposal, and it broadcasts the following channels:

http://www.dtg.org.uk/retailer/dtt_channels.html

BBC1
BBC2
BBC3 / CBBC (time-share)
BBC4 / CBeebies (time-share)
BBC News 24
BBC Parliament
BBCi
Community Channel
301/302/303
Radio stations

The radio stations consume 1888 kbps in total, leaving 34.312 Mbps

The Community Channel only broadcasts from 6am to 9am, which won't clash
with the BBC HD channel.

Assuming the BBC HD channel requires 10 Mbps, that leaves 24.312 Mbps for
the remaining channels.

If the BBC invested in new MPEG-2 encoders like the commercial TV channels
did a couple of years ago, and then allocated the 24.312 Mbps as follows, I
don't see why they couldn't fit the HD channel in:

BBC1 - 3.5 Mbps
BBC2 - 3.5 Mbps
BBC3 - 3.5 Mbps
BBC4 - 3.5 Mbps
BBC N24 - 3 Mbps
BBC Parliament - 1.5 Mbps
BBCi & 301/2/3 - 5.8 Mbps combined
Total = 24.3 Mbps

The bit rates above for BBC1-4 are *higher* than the commercial TV channels
are
using at the moment, and apart from BBC1 a bit rate of 3.5 Mbps is about
what they're using at the moment. So if the BBC purchased the same encoders
that C4, ITV etc bought a couple of years ago when they reduced the bit
rates of their channels, the quality would be okay BUT we'd be able to get
the BBC HD channel for the full 9 hours, which I would say is a good
trade-off.

Issues
====

BBC Parliament's bit rate looks a bit low, but it's only a quarter-screen
channel, and at the end of the day who watches the bloody thing? It seems
that it's main reason for being there is to make the politicians feel
important, and I dread to think what the audience figures are for it.

I can't find out what the combined bit rate is used for BBCi (excluding
301/2/3), but I recorded 301 and 302 last night to see what bit rate levels
they were using and they were as follows:

301 = 2.93 Mbps
302 = 3.45 Mbps

But they were both carrying sodding CBBC stuff at 10.30pm - shouldn't kids
be in bed by that time??

As far as I'm concerned, squeezing the bandwidth that's used for the BBCi
and 301/2/3 streams would be well, well worth it, because I don't think the
BBCi stuff will be used much, and they could still broadcast, but just at a
reduced bit rate, say.

I might be missing something out above - if I am, please point it out. But I
have a suspicion that the BBC is playing a political game with its
bandwidth, because it is claiming that it hasn't got enough in order to try
and persuade Ofcom to give it some spectrum gratis. But I think it's now
clear that Ofcom and the government have got absolutely zero intention of
budging on this issue, so they should forget it and pull all the stops out
to launch the HD channel.


--
Steve - www.digitalradiotech.co.uk - Digital Radio News & Info



.

Quantcast