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The digital super highway

By Rod Reynolds
Created 09/04/2009 - 12:50

Rod Reynolds is new to Webdiary (although it has been inflicted upon him for ages). He is a chartered engineer with nearly 40 years in the communications industry from the days of the PMG through to the privatising Telstra in the late 1990s. For the last twelve years he has been intimately involved in intellectual property associated with ecommerce solutions for large businesses. As light relief he sings in choirs, records music and produces CDs, and is trying to turn his residence into a 21st century version of Sir John Soane’s museum [1] – despite Fiona’s best efforts at prevention.

This is his take on the Government’s announcement of the National Broadband Network – thanks for putting quill to keyboard, Rod.


The digital super highway: A communications engineering view
by Rod Reynolds

The broadband push was a political promise at the last election that went to tender. The RFT documentation was restricted in scope – probably aimed at getting an early solution. Modern communications solutions tend to last for about 15 years and this one was going to take something like that to roll out fully. A clue to that is that the Telstra Digital Future Mode of Operation project on what was a predominantly existing network was only close to complete after 6 years after an initial estimate of half that – and that was only a $3.5Billion project. Putting to one side the commercial and political arguments on the ownership and delivery of the super highway, the “expert panel” (with whatever conclusions they argued) came to the obvious result that by the time the interim solution was close to delivery, that it was time to start all over again with a next generation solution.

Arguments about “fibre-to-node” and “fibre-to-premises” are relevant but may not be all that critical after all from a performance and function point of view. What is more important is that the old copper pair network that connects the system to the users has reached its “use-by date” when high capacity duplex data links push the limits of what can be carried on a given cable. You simply have to have more bandwidth in the ground, and fibre and new high density digital copper cable both provide that – although the fibre solution is generally the cheaper and has the higher performance.

The whole issue of data-carrying capability of the internet and associated services is complex in the extreme, and a very small proportion of the total users could actually use the capacity being talked about today, let alone know what to ask for. 100MB/sec can do an awful lot, and very few data sources can even generate data at that speed, nor are they likely to with the exception of a few business applications. And there is a technical detail to consider: Most of us are users of ADSL services. The “A” in that stands for Asymmetric, and that means that even in ADSL2 that the download is at 20MB/s while the upload is only at 1MB/sec. And for networking reasons the fastest download that most users see on that “super service” is only about 6MB/sec.

Technically then, this raises more questions. Does any consumer need or could even use 100MB/sec? If fibre is put into the ground for the first generation, could it ever be upgraded? (Oh, something that we are not being told is that the life of fibre is not all that good – especially where water contamination is possible as in a low cost suburban distribution system.) Internet 2 and beyond will provide all those other services like television etc etc. but in the Australian scene where we are just introducing free-to-air Digital HDTV, the idea that paid services via fibre will be viable is a nasty echo of the cable TV experience here.

The so-called “expert panel” who were looking after the recent botched RFT could only see the long term solution – ie they had no idea on how to deal with an incremental path (I suspect that most of them were escapees from reality) – and fed Rudd with a way of spending more money (financial injection) which was consistent with spending reserves (politically OK) and making it look as if he knew what he was talking about (OMG). The reality, of course, is that this is a massive project and every bit of that $43Billion will be needed – and by the way, they had better be thinking about replacing the roads and pathways too because they are already full of old cable and broken ducts that will have to be replaced as part of the project – er – and there is gas water power and lots of other services in there too in some places…

The current broadband system was based on inter-exchange networks, and cable TV and was introduced from about 1992. We could not have done any better at the time at any cost that the public might have accepted. The current plan to install a 100M to the home fibre network is throwing money at the problem and hopefully they will find a cheaper way of doing it before the job is too far under way. Do the arithmetic … $43Billion to serve 25 million people or maybe 5 million locations (90% of 4 – 5 persons per family). That means a capital cost of $8,600 per unit, and using a common amortization factor means a cost to that location of about $150 to $200 a month just for the link. Nearly all the links are domestic and any argument that the commercial or business sector will be enough extra to cross-subsidise the retail sector is fanciful. On top of that you have to have the ISP and content generations sectors etc who wants another $40 a month plus content costs. Suddenly your internet or “digital connection” account is starting to look like $250+ a month which might be fine for a business customer (and what they are paying today for a perfectly good broadband system with dual ADSL giving them effectively a 54Megs per second link) but not too many consumers are going to like that. Sorry – I am not confident that we have heard the last of this…

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