[3GScottishUser]

From Mobile Today (04/11/2005):

Bruce Renny, Rok Entertainment’s group marketing director, claims that if mobile TV took off, there is still a question mark over just how much TV traffic 3G networks can really take. ‘There’s no single [3G] network that could handle more than 100, 000 TV sessions simultaneously,’ he says.

http://www.mobiletoday.co.uk/artman-test/publish/article_895.shtml

[Ben]

HSDPA will help greatly, if it makes it in time. I think streaming TV over the 3G networks is going to be an excellent test for the mobops, ensuring everything is working as it should and allowing them to tweak things for better efficiency. It means they can put a really high load across their infrastructure that might not otherwise occur for several years. Yes, there could be hiccups along the way, but it should result in more reliable performance for all of us once all the traffic gets shifted over to DVB.

[3GScottishUser]

I wonder exactly how many users can watch TV on the network? One would have to factor in all the voice, video, SMS/MMS and data usage as well of course so the number will be smaller than that suggested I expect.

Tekkies do some maths!!

[Hands0n]

And how exactly does Bruce Renny, who does not work in mobile networks, know how many concurrent mobile TV users any 3G network can support?

What is the bottleneck? The video servers? The terrestrial network infrastructure (unlikely). Or the airtime interface (the UMTS bit of the equation). Is he talking concentrated in an individual cell or spread out across the entire network?

I, being an old networker, do not buy into that very much unless the mobile network is underpinned by a significant fundamental design flaw. In which case, for an extortionate fee, I would be more than happy to design something more appropriate for them, as could any networker with an ounce of skill and experience. So, unless they used a school leaver to do the design and implementation I can't see it myself. 100,000 video sessions for a national network seems piddlingly small to me.

The other traffic, voice and videocall excepted, can quite easily take its time transiting the network as it is not realtime data. The end user would not realistically percieve any intermittent packet delay in transmitting that data across the infrastructure.

I smell a scare story here. One without any real substance. But for what reason?

[3GScottishUser]

Looking at the specs for UMTS I found out the folowing "transceiver capacity is typically from 400 kbits/s to 700 kbits/s per transceiver."

Now assuming Mobile TV uses about 50Kbits/s that means 14 users can max out a cell site!! Take things a stage further and assume there are about 7000 Vodafone 3G sites in the UK. Multiply 14 by 7000 et voilla, 98,000 max!!

Based on figures from http://www.umtsworld.com/technology/capacity.htm

Looks like an interesting problem that as Ben suggests HSDPA might become a solution for.

[Ben]

I smell a scare story here. One without any real substance. But for what reason?

*cough*
"‘Our offering [at £9.99 per month] represents fantastic value for money,’ Rok’s Renny insists. ‘Especially when you compare it to what video iPod users are being asked to pay, which is in the region of £2.50 to £3 for just one video clip. With Rok you get a whole month’s viewing for the cost of just three
clips.’"

Sounds like Rok's Renny is bigging up his service ;) (Edit: Surely ones bills would be enormous in data charges?)

I do think there could be underlying problems with backhaul in certain areas where there's only 2mbps to feed several cells. The networks will keep pace with demand, though.

[Hands0n]

It is my thought that Bruce Renny is being, perhaps, a bit of a scare mongerer. Although perhaps correct in his statement the problem only arises if and when mobile TV takes off. I suspect he is bringing into the light something that the mobile operators know exists as a natural step in the deployment and development of 3G. Who, after all, truly builds a network for maximum capacity on day one? It is the job of the capacity planners to correctly assess likely demand and programme in network build and development through the life of the network. 3G merely raises some interestingly new challenges for them.



Now assuming Mobile TV uses about 50Kbits/s that means 14 users can max out a cell site!! Take things a stage further and assume there are about 7000 Vodafone 3G sites in the UK. Multiply 14 by 7000 et voilla, 98,000 max!!

I'd take much of that article with a pinch of salt. Further down the page it is stated .....


Before UMTS networks are on air and customers start to use high speed services, network capacity calculations are anybody's guess!


The referenced page is [obviously] quite old and therefore the numbers are all theoretical. The practical aspects of networking do not often match the theoretical calculations. Now that the UMTS networks are on air and customers are starting to use high speed services the guesswork can be eliminated. Over to the network analysts and capacity planners.

But it is interesting to note then that the alledged bottleneck is the 3G (UMTS) part of the network infrastructure. For sure, the backlinks (from transmitter mast to network infrastructure) are technically limited only by terrestrial link speed technology and what the mobile ops is willing to pay to service their mast stations.

And so, if it is indeed the 3G component that needs work then HSDPA, as Ben says, will provide the next step in the solution to providing increased network user capacity. Before that [HSDPA] is maxed out the successor to it will have to have been developed.

If not, then we're all in big trouble :D