The sad truth about ADSL

1999-07-01

If the rumours are true, BT is on the point of rolling out ADSL services in the UK. ADSL presents both a problem and an opportunity to BT, the company which pretty much “owns” the link between the local exchange and the household. BT has come under fire in the past for not going the (literal) extra mile for its consumer customers: suitable pricing models for home use of ISDN, for example, were a case of too little, too late. ADSL provides a new opportunity for BT to demonstrate that it can provide cost-effective, high-bandwidth services to SoHo and consumer alike.

Issues remain, of course. Firstly, BT are unlikely to be in a position to manage a national migration to ADSL in a short timeframe. For a start, there is an infrastructure rollout cost for BT, to enable its local exchanges. Also, and maybe most importantly, there is a benefit tradeoff. ADSL is only appropriate for customers requiring high-bandwidth digital reception – this translates to internet users prepared to pay the cost of the access device and the subscription. Although we all think fast access to the internet would be a good thing, how much are we really prepared to pay for access from the home? Until there is a critical mass of customers, BT will be loathe to roll out the service in a particular area.

Secondly, there is the bottleneck issue. The internet acts a lot like a hard disk and controller – it has seek time, access speed and throughput as its major characteristics. Surfers can employ ADSL to increase local throughput but can do little about access speed, for example to a poorly connected site. Seek time is still largely down to knowing what we are looking for or how to find it. When designing a computer system, a lot of effort is made to “balance the bottleneck” – that is, to ensure all components work together so that no one component is slowing down all the others or is underutilised. The internet still has a long way to go before all of its bottlenecks are balanced.

BT will inevitably roll out ADSL, but probably more slowly than the commentators would like, even though the full benefits of fast internet access will not be realised for a good while. What does this mean for the consumer? ADSL should be considered in the round, as one of a number of protocols for data transmission on telephone wire. It will not be the only mechanism, just as the telephone line will not be the only medium – to get the fullest picture we must think of wire, cable, fibre, satellite and wireless and the variety of protocols they support. The biggest issue will ultimately be cost and there is currently such a diverse set of pricing models that it is difficult to gauge the relative benefits of each. This will change, but in the meantime ADSL is more likely to begin with a whimper than a bang.

(First published 1 July 1999)