NTL investigates 18Mbps next-generation broadband technology

Posted on 18 Mar 2005 at 12:47

NTL has been quietly testing next-generation broadband technology that will raise the maximum speed available in the UK to 18Mbps.

ADSL2+ trials were carried out last month and have now been extended to test the viability of on-demand HDTV (high-definition TV) streaming.

Although 18Mbps is the highest downstream speed attainable, in reality it will only be reached by premises within 1km of exchanges, although the technology will boost performance across the board.

BT has also been testing the technology, with a handful of its employees enjoying super-fast Internet links. It is also preparing to embark on a new set of trials on existing ADSL connections to determine the viability of speeds between 2Mbps and 8Mbps.

ADSL2+ technology has been around for some time, but its introduction in the UK was held up by a conflcit with the VDSL technology that enables ADSL signals to reach properties more than some 6km away from exchanges. While other countries simply scrapped VDSL in favour of ADSL2+, UK ISPs thought this too drastic a solution. However a workround has now been found and the UK Internet standards body - the Network Interoperability Consultative Committee - gave its approval to ADSL2+ in January.

ADSL2+ works by doubling the frequency used for downstream data traffic to 2.2MHz, increasing data rates on the shortest lines to as high, in theory, as 24Mbps. An optional mode also allows for upstream speeds to be increased. National network providers such as BT, Easynet and Thus have already begun upgrading their backbones to support the higher data throughput.

Faster wireless is also a step closer today, after the IEEE decided on a final specification for 802.11n, which will succeed the current 802.11b and g standards used at present.

802.11n will double maximum speeds to 100Mbps, though even higher rates of 315 or even 630Mbps may be possible. The standard is backward compatible, with b and g and certified-products expected to be commercially available in 2006 or 2007.

Author: Simon Aughton