BT expands white-space trial to Cornwall

BT will extend its white-space wireless broadband trial by testing the technology in a rural location in Cornwall.

BT will test the feasibility of providing broadband using the gaps in digital television radio spectrum, known as white space, in a new trial in Cornwall. Image credit: Ben Woods

The company announced plans to trial the technology on Wednesday in Brussels. It will replace the current 4G trial in Cornwall jointly run by Everything Everywhere and BT. The company had previously run white-space trials in the Isle of Bute and Cambridge using the technology; with the latter largely focusing on machine-to-machine (M2M) communications.

"BT can confirm it is planning to extend its trial of TV white-space to Cornwall following a successful initial trial on the Isle of Bute. The Bute trial has generated some encouraging results and so it is time to extend it to a larger audience and to test the technology further," BT told ZDNet UK in a statement. "The new trial will take place in the same area in which we have been testing LTE (long term evolution) technology with Everything Everywhere."

However, unlike the current trial — approved by Ofcom for extension to July — which uses the 800MHz spectrum band to deliver speeds of up to around 25Mbps, the white-space trial will use frequencies in the Digital Terrestrial TV (DTTV) bands of between 470MHz to 790MHz. It will begin once the current 4G trial in Cornwall finishes.

The technology uses low-power transmitters on locally unused DTTV channels to deliver the broadband service without affecting TV services. Interference is still possible and the white-space system must be able to find and avoid conflicts, by local monitoring or by instructions kept in a central database.

Viable technology

Despite the technical and regulatory challenges of using white space for broadband, Ed Richards, chief executive at the telecoms regulator Ofcom, said it is a viable technology that needs further testing and exploration.

"Technology in this area, as in other areas, is moving forwards at a fast pace. But we should also be confident in the groundwork that has been established. The science is clear; the technology is in many areas already there and continues to improve quickly. So there is a significant opportunity here that we need to grasp," Richards said.

"The technology for more dynamic spectrum access has come of age without being exploited fully. At the same time, consumer demand for services has exposed the limitations of the current arrangements."

BT said it is conducting further trials to see how a commercial deployment would work and to see how well it performs in comparison to the 800MHz trial scheme.

The government aims to provide super-fast broadband services to 90 percent of the UK before 2015, with a minimum connectivity of 2Mbps everywhere. However, BT believes that two to three percent of UK homes will still fall within a broadband 'slow spots', defined by the company as slower than 2Mbps.

4G rollout

The UK rollout of 4G data services has been held up by repeated delays to the spectrum auction process, causing Richards to call for operators to stop "gaming the system" over the auction proposals. However, in January Ofcom proposed new terms for the upcoming auction in a bid to clear up the deadlock. The auction is currently set to take place at the end of 2012.

Meanwhile, Broadband UK has already activated TD-LTE services in London in time for resellers to begin offering the option to some users in the Southwark district from May.

Everything Everywhere has also said it is ready to switch on 4G services for some users before 2013 but the company still requires regulatory approval from Ofcom.

Meanwhile, a report prepared by management, engineering and development consultancy firm, Mott MacDonald, for Ofcom in January 2012 suggested that the upcoming spectrum auctions could include "an obligation for rail corridor coverage".

The report, which focused on rail corridor 'not spots', said that one of the key problems to filling in areas where coverage is poor is that there needs to be "more active co-operation" between mobile network operators (MNOs) and Network Rail "where little or no benefit is perceived by the MNOs at the moment".