Wednesday, April 25th, 2012 (11:17 am) - Score 3,371

The TV White Spaces Consortium, which comprises 17 international and UK technology and media companies (BT, Microsoft, BBC, Virgin Media, Alcatel-Lucent etc.), has reported that their 10 month long trials of White Space (IEEE 802.22) wireless broadband tech in urban and rural areas around Cambridge (England) have been “successful“.



The new solution is unique because of its crafty ability to harness the unused radio spectrum that exists between Digital TV (DTV) channels, which is usually left free to limit problems caused by interference, to deploy internet coverage in even remote locations. But instead of leaving this untouched Ofcom has decided to encourage its development, with devices potentially being offered on a licence exempt basis.

Analysis of the trial found Cambridge has “significant television white spaces capacity” (i.e. 20 white spaces channels corresponding to 160 Megahertz in total, of which 13 (104MHz) were allowed in the test licence) and that all of the solutions tested, such as rural wireless broadband, urban pop-up coverage and the emerging “machine-to-machine” communication, could be catered for.

Even the complications of needing to maintain a dynamic geolocation database (DTV channels change all the time), provided by Microsoft and Spectrum Bridge, apparently proved to be a “reliable way to control frequency use by the white spaces radios and to quickly adapt to changes in spectrum usage“.

Communications Minister, Ed Vaizey, commented: “I welcome the success to date of the Cambridge White Spaces Trial. Leading innovators from the UK and beyond have demonstrated the potential that television white spaces can have for meeting the UK’s broadband needs. Developments such as this endorse the leadership position that the UK can take in enabling more efficient use of spectrum by opening up an array of opportunities for wireless applications for consumers and businesses alike. I find the idea of using white space devices to deliver broadband to rural communities, or to expand the range and quality of urban Wi-Fi hotspots, exciting. This can form a significant contribution to our thinking as we consider how to maximise the value of the spectrum below 1GHz. I look forward to hearing the next chapter of your progress.”

As a result of all this the consortium members have recommended that the UK regulator, Ofcom, complete its development of the “enabling regulatory framework” (i.e. Draft Statutory Instrument) in a “manner that protects licensees” from “harmful” interference and encourages innovation and deployment.

White Space Trial Summary • City centre coverage. The consortium set up base stations on the north side of the Cambridge city centre in four pubs and a theatre, aiming to provide widespread coverage, including “pop-up” Wi-Fi hotspots. The base stations were connected to dual omnidirectional wide-band antennas mounted on rooftops (radios and antennas provided by Neul), enabling considerably further coverage than could have been achieved with conventional Wi-Fi, in 2.4GHz, for example. The tests showed that TV white spaces can help extend broadband access and offload mobile broadband data traffic. These hotspots can enable users to enjoy data-intensive services such as online video provided by BBC iPlayer and Sky Go during peak usage times, when additional capacity and wider reach is needed. • Rural connectivity. A base station was installed at TTP’s headquarters in Melbourn, a rural community south of Cambridge, and linked to a household in Orwell. The residents benefited from radical improvements in their broadband service, up to 8Mbps net speed achieved over 5.5km links, within an 8 megahertz bandwidth, using a modified, prototype version of the Neul Weightless technology. TTP anticipates it would be possible to achieve speeds greater than 20Mbps from its headquarters to Orwell using radios further optimised for rural broadband connectivity while occupying a single, dedicated TV white space channel. • Machine-to-machine. Industry forecasts estimate there will be more than 50 billion connected devices by 2020, with a good proportion of these communicating and sharing information wirelessly, enabling a wide range of applications. As such, the trial explored machine-to-machine communication, often referred to as the Internet of Things. Utilising the available white spaces, an application developed by BT and Neul sent an alert message to the city council when city dustbins were full and needed emptying. TV white spaces are uniquely placed to unlock the potential promised for the Internet of Things. • Location-based services. Nokia and Spectrum Bridge developed a location-based service application that was deployed in the Imperial War Museum in Duxford, one of Europe’s leading aircraft museums. As museum visitors move around the collection, they can receive prompts on their smart mobile device informing them about the items they can see and offering a rich array of related content. • Lab and field measurements. In addition to the implementation of trial networks, Arqiva, BBC Research and Development, CSR and CRFS spearheaded considerable laboratory and field measurements to better define the parameters needed to develop the regulatory framework required to enable the use of white space devices. The results of this work are being provided to the relevant UK and European regulatory bodies. In addition, the BBC developed the first version of a UK-wide database, which illustrates the typical availability that might be expected for TV white space devices following the completion of the UK digital television switchover.

Certainly “White Space” technology appears to have its merits, although the trials also revealed a few weaknesses, particularly in terms of performance and coverage. The official specification, which has yet to be fully implemented, suggests that download speeds of up to 22Mbps per channel (Megabits per second) could eventually be possible (shared bandwidth, although several channels could be used for faster speeds) but the current technology has shown itself to be far from perfect (BT’s unimpressive trial speeds).

It should be said that this is still new tech, which will be improved and refined, but at present it might be better to focus on expanding future 4G coverage. Delivering slightly faster speeds into remote and rural communities, while useful in the short-term, is still just a temporary fix and could risk storing more problems up for the future when even faster access is required.

There’s also no clear mention of costs, which is especially important as operators would need the solution to be economically viable (at present the price isn’t quite where some operators would like it to be). On the other hand the solution, if properly refined, could still provide a significant improvement; even if it is short lived.

UPDATE 25th April 2012

TTP, one of the companies involved in the Cambridge TV White Spaces Consortium trial, has suggested that White Space technology could help drive the UK economy forward by providing high performance rural broadband for up to 2 million “un-served” premises across the country.