Sunday, 11 October 2009

More About ADSL2+

Since I posted about ADSL2+ a couple of weeks ago it came to my attention that the exchange I am connected to is due an upgrade before the end of this year. I had mixed emotions on that one: on the one hand at least BT are spending some small amount on this exchange on the other it does rather diminish the impact of selling a community broadband project to the community.

So I looked into it a little more closely. On the surface of it ADSL2+ allows a downstream throughput of up to 24MBit/s and upstream up to 2MBit/s - or about 3 times better than ADSL, at least for the headline rates. Then I found this graph:



What stands out from this is the very steep degradation over distance and the fact that if your loop length (distance from the exchange) is more than about 3,000 feet then this 'new' technology will bring virtually no improvement to your speed. So, yes I will be connected to an exchange that will deliver 'up to' 24MBit/s and will therefore be part of the statistics that show what broad coverage we have in the UK and yet I will be no better off than the (sometimes) 2MBit/s I get today.

In USC terms (the Universal Service Commitment of 2Mbit/s to every household in the UK) I guess my house will be ticked off the list although most days I don't even get close to 2M.

Still, those emotions are unmixed now! My sales pitch has been given another boost!

1 comment:

  1. thanks for explaining all this so clearly. Let us hope more people continue to get IT and see through the press releases and balarny that the telcos dish out to joe public...
    well done.
    chris

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