Kitz Forum
Broadband Related => Broadband Technology => Topic started by: burakkucat on January 28, 2015, 12:09:18 AM
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There is a document available (http://stakeholders.ofcom.org.uk/binaries/research/technology-research/asses.pdf) for download from the Ofcom site, entitled Assessment of the Theoretical Limits of Copper in the Last Mile.
The Executive Summary begins with the following paragraph --
This is the final report from our assessment of the theoretical limits of capacity of the
approximately 26 million copper pairs which form the ‘last mile’ of the UK’s telephone
network. The objective of our work was to look beyond the limitations of current
equipment to the fundamental theoretical limits of BT’s copper twisted pair network
according to communications theory.
There may be some useful nuggets of information contained within but I did not notice anything when I quickly scanned that document.
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To me, the significant sentence says interference and other limitations are ignored !
It sounds like the Greek attitude to debt !
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Is that the Sagentia report?
The report itself is on various models of how to make use of the "last mile", but it does have a section on the data about the access network that they base the model on.
The data was originally supplied by BT to NICC in the form of cumulative distributions of attenuation, which they have converted (using BT's own model of 0.5mm copper) to line lengths. It then shows the distributions for a combined E+D side lengths, and the distribution of just D-side lengths.
For example, the 50th percentile combined line length is 3200m, while the 50th percentil D-side is 450m (just D).
That part I have found interesting and useful...
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Must be awesome working for a quango.
Get paid a salary to outsource work that has little value outside of academia :)
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Fascinating read, although I suspect I'd have got a lot more out of it 40 years ago, when such maths were still fresh in mind from that degree all these years ago.
One thing, to note above all imho, they do emphasise in the introduction that they are exploring theoretical limit, not practical limit. One aspect of such theory that always fascinates me is the maths for theoretical limits were laid down in Shannon's Theorem, 1948, ie days of Alan Turing. Yet the theory still holds good, and remains the reference today. A clever chappie.
Personally I am very grateful that such research is being done. And reassured to see that we do not yet appear to be close to the theoretical limits, hence justifying further work in development of practical deployments, and reason for optimism that things may continue to improve... :)
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Is that the Sagentia report?
It is, indeedy. :)
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Fascinating read, although I suspect I'd have got a lot more out of it 40 years ago, when such maths were still fresh in mind from that degree all these years ago.
Likewise. b*cat takes a look at the mathematics presented in such a report and having noted that he should understand it, usually makes the executive decision that it is time for a little nap. :D
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You know that 'wow' feeling you sometimes gets when reading certain documents? That someone incredibly clever, has put it together? This is one of those, for me.
Well done :)