Sheffield almost into 21st century
Tuesday 10 March 2009 11:06:08 by Andrew Ferguson

According to the The Star, a newspaper that covers South Yorkshire, next generation broadband is about to arrive in Sheffield and it will be an entirely new broadband service, not simply an improved version of what already exists.

The reality is that the 21st Century Network (21CN) roll-out by the BT Group arrives in Sheffield by the end of the month, and will cover around 60% of the phone network in the city. Claims that 60% of broadband connections will benefit is much harder to substantiate. 21CN broadband is actually just ADSL2+ and is provided by MSAN's in the local telephone exchange (a MSAN is a DSLAM providing both telephone and broadband services).

People do not need to panic that their broadband will suddenly migrate to a new service or that their existing modem will not work, which the newspaper article could have people thinking. Current ADSL only modems will work under ADSL2+ and migration will not happen en-masse, it will require your broadband provider to actually decide to migrate the line to WBC (the BT Wholesale 21CN broadband product name - Wholesale Broadband Connect). This is only going to happen a limited number of people since Andrews & Arnold and Entanet are the two providers making use of WBC currently. BT Retail the largest ADSL provider has only recently started mentioning that ADSL2+ offering speeds of up to 20Mbps is on the way.

While ADSL2+ will offer almost three times the headline maximum speed, the fact that the speed falls away as the length of the telephone line increases, means that around 42% of lines will connect at 9.5Mbps and faster, for those connecting at 2Mbps or slower ADSL2+ is not likely to offer a significant improvement in connection speed. One reason providers may be slow to adopt even faster connections, is that to cope with peak demand they will need to invest in more back haul capacity, otherwise having a faster connection to the exchange will be irrelevant as the bottleneck will just be somewhere in the dark recesses of a providers network.