Millions of homes will be unable to get a faster broadband product that BT will begin trialling later this year, because they live too far away from their telephone exchange.
This technical limitation, which is more severe than the existing restraint on the availability of 512Kbps ADSL, means that more UK residents could soon find that their location has a big bearing on the speed of Internet connection available to them.
BT Wholesale announced earlier this week that it will begin a six-week trial of a 1Mbps ADSL product called IPStream Home1000 in October. This will be available from any broadband-enabled exchange. Any ISP can join in the trial, and there's no limit on the number of customers that can take part.
According to BT, this product is "aimed at consumers looking to upgrade to a higher bandwidth. It will also be an attractive solution for the more demanding first time broadband user."
But anyone who falls into these categories had better hope that they don't live too far from their telephone exchange. IPStream Home1000 will only work on a phone line that is no longer than 3.5km.
Today's 512Kbps ADSL packages work over a longer distance, because they are "rate adaptive", which pushes their maximum range up to 6km (it was previously 5.5km). This means that some 97 percent of homes within a broadband-enabled area can get the technology.IPStream Home1000, though, is not rate adaptive.
A BT spokesman told ZDNet UK that this means that "approximately 70 per cent of households within enabled exchange areas" will be able to receive 1Mb broadband down their phone line. He added that he wasn't aware of any plans to add rate adaption to the IPStream Home1000 product.
Today, BT has broadband-enabled more than 1,500 local telephone exchanges, enough to give access to ADSL to around 70 percent of the population, or close to 18 million households. The 3.5km restriction means that some 5 million of these 18 million homes won't be able to sign up for IPStream Home1000.
BT believes its ADSL coverage will reach 90 percent of the population within a couple of years, raising the number of homes connected to a broadband-enabled exchange to around 22.5 million. Then, the 3.5km restriction on IPStream Home1000 will means that up to 7 million people won't be able to get the 1Mb broadband.
With almost a third of the UK population unable to get any form of broadband from BT at the moment, being restricted to a 512Kbps Web connection doesn't sound like much of a hardship. It is inevitable, though, that the launch and take-up of innovative and bandwidth-hungry applications and services in the future will make faster broadband more of a priority.
1Mbps consumer broadband packages are already available in some parts of the country, from telcos such as Bulldog, Telewest and NTL. Telewest revealed earlier this year that 10 percent of its customers shifted up to 1Mbps once it made this faster bandwidth available -- a sign that IPStream Home1000 is likely to be popular with today's ADSL home users.
IPStream Home1000 will cost ISPs £23 (excluding VAT) per month. This is about £10 per month more than they are charged for the equivalent 512Kbps wholesale product, suggesting that users will be charged up to £40 per month for the faster service.