Mixed Signals
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Friday 8 May 2009, 3:08 PM
The true cost to the BBC of iPlayer...
Which does raise the question, though: is it value for money?
I'm trying to work out how much more - or less - it costs the BBC to deliver a TV programme over iPlayer than it does to transmit it in the old-fashioned way.
This is surprisingly difficult to do, but I think I have an answer: it costs around sixteen thousand times as much to stream a programme as to broadcast it.
Here's how I came to that conclusion. At gigabit speeds, Internet bandwidth costs around a penny per megabit per hour (I'm assuming the BBC is buying it in at around £7/Mbps/month, and there are 744 hours in a month). An HD stream is around a megabit, so the cost to the BBC of one person watching one programme for one hour is a penny. More or less.
Now, the BBC 1 analogue TV transmitter at Crystal Palace is a nominal megawatt. Analogue transmitters are very inefficient, so it could need twice as much actual power - if it was actually transmitting a megawatt. Because of the structure of a TV signal, most of the time it's transmitting far less. And I don't know the cost to the BBC of the electricity (and anyway, the BBC doesn't operate the transmitters itself any more). So with all those variables, I'm going to just assume it's taking a megawatt, and that a megawatt/hour costs around £100.
Crystal Palace analogue TV has a catchment area of around 15 million people. Despite the BBC's very best efforts, they don't all watch BBC TV all the time - the average is 20 hours a week, or about eight percent of the time. Which is 300 million person-hours per week, or 1.8 million person-hours per hour - and that hour costs £100. That means one person watching one hour of TV from Crystal Palace costs the BBC sixty micropence.
That's sixteen thousand times cheaper than streaming.
Any better guesses?
PreviousComments on this post
Surely it would be wiser to compare the cost of operating the early television transmitters.
Once the BBC have the numbers to make investment in better IP streaming technology a sensible decision, they will/are.
Peers-to-peer streaming technology for example.
The BBC annual report has a whole collection of financial information.
It doesn't offer a per unit cost of iPlayer but it does offer a cost for conventional distribution.
http://www.bbc.co.uk/annualreport/
Assuming I've interpreted the figures correctly (page 141/143)
In particular costs of TV distribution (2008) = 104.8 million
cost of online service distribution (2008) = 15.4 million
However arguably iPlayer is still growing in popularity, so the figures will grow. But against this, the BBC has to distribute the signals to every one of the transmitters around the country, while the internet costs include this, I guess.
The tv figure seems to be about 1.75 per tv per year based on ofcom's 60 million tv set figure.
EDIT: If it's 1.75 a year then a person could watch 3.37 hours of television a week on iplayer and it would work out the same.
(Maybe?)
The BBC did try peer-to-peer with the early (non-streaming) iPlayers, but found it didn't work very well and created more problems than it solved. They're still looking at it for streaming, but that's a lot more complex than P2P file transfer - and there are still issues about people wanting to control their upstream bandwidth.
It's very hard to work out exact distribution costs. Someone told me that the transmission system costs the BBC £300 million a year, which is around a fiver a year per person. That's around 500 hours of penny-an-hour streaming, while current TV consumption of terrestrial BBC programming is around six hours per person per week (not twenty, as I had at first thought) - or around 300 hours annually. That's 18 billion hours, which is £187 million worth.
With those figures, streaming is cheaper! What I don't know is what else that £300 million gets the BBC asides from BBCs 1 and 2 - I don't know how to extract the terrestrial TV costs from the digital and radio components. (The ultimate owner of the BBC transmitters, and every public service transmitter in the country, is an Australian bank called Macquarie.)
Investigations continue...
The BBC has peering agreements with ISPs which means that it doesn't have to bear the full cost of distributing iPlayer content:
From http://www.bbc.co.uk/blogs/bbcinternet/2009/05/interesting_stuff_20081206_bbc.html
"Nothing is really achieved by direct download from the BBC - that would cost waaaay too much money, as proven by the total data usage. Instead, they set up peering agreements (free, http://support.bbc.co.uk/support/peering/) which allow them to, with a little discussion, put iPlayer CDN (content delivery) boxes in datacentres and even possibly ISPs space in telephone exchanges, for a low/free/reasonable cost"
Also, there will be some cost associated with transcoding all the content into the 14 different formats needed by iPlayer - different codecs, bitrates, etc.
(BTW, registering to post a comment here is really long-winded and tortuous! This is my third attempt at posting a comment, too... the previous two attempts appear to have vanished!)
Yes, peering makes a big difference to connectivity costs...
We're actually quite a long way into a project to simplify registration - I wish I could say more about that, because it's a surprisingly complex and interesting area, but as it's intimately involved with a lot of our other business areas I should probably better not.There'll be some big changes coming...
As for the vanishing posts: that is our anti-spam system, which is triggered by (among other things - again, I can't say too much: we're in a constant battle with the spammers) too many links. Which can be as few as two.
Both these things are annoying and I apologise for them. Thanks for perservering!
