Advanced Television

Ofcom next steps for ‘white space’ devices

November 22, 2012

The launch of Europe’s first consumer ‘white space’ devices has moved a step closer as Ofcom publishes consultation proposals for a framework to exploit  the technology in the UK.

A white space device uses gaps in radio spectrum, called ‘white spaces’, which exist in between frequency bands that have been reserved for TV broadcasting. Use of these white spaces would allow devices to transmit and receive wireless signals for applications such as broadband access for rural communities or innovative ‘machine-to-machine’ networks.

Compared with other forms of wireless technologies, such as regular Bluetooth and Wi-Fi, the radio waves used by white space devices will be able to travel larger distances and easily through walls. This is because they would use the lower frequencies that have traditionally been reserved for TV.

Spectrum itself is a limited resource that is in huge demand, fuelled by the recent explosion in smartphones use and other wireless applications. White space devices offer a creative and efficient way to use spectrum that would otherwise lay fallow.

Ed Richards, Ofcom Chief Executive, said: “From rural broadband to enhanced Wi-Fi, white space technology offers significant opportunities for innovation and enterprise in the UK.

“It also represents a fundamentally different approach to using spectrum by searching and recycling unused gaps in the airwaves. This could prove critical in averting a global spectrum capacity crunch, as consumers demand more bandwidth over different devices.”

The framework that Ofcom has proposed is designed to ensure that the devices do not interfere with existing licensed users of the spectrum, which include DTT and wireless microphone users.

As part of that framework, Ofcom proposes to allow white space devices to operate without the need for a licence. New legislation is needed to allow this to happen. Ofcom has published an example of how this legislation might look.

Under Ofcom’s proposals, a white space device will not be able to start transmitting until getting clearance from an online database qualified by Ofcom. This database will provide updated information on where the white spaces are and the power level that devices would need to be restricted to if they wanted to use them.

Enhanced Wi-Fi: The majority of current Wi-Fi devices operate in spectrum at 2.4GHz. White spaces could provide new capacity, while boosting the range of devices, potentially enabling Wi-Fi networks that stretch across towns and cities. This is due to the lower frequency of TV white spaces (typically between 470 MHz and 790 MHz).

White spaces could be used to provide rural locations with broadband services. In practice, this could be achieved by building a network of transmitters that use white spaces to link remote houses and villages to larger towns that are already connected to the Internet.

Ofcom will next year notify the European Commission of its proposed technical regulations for white space devices. This will be followed by a ‘standstill’ period of three months for the Commission to inform other Member States and to allow opportunity to comment on Ofcom’s plans. In 2013, Ofcom also plans to finalise the arrangements for databases and the technical parameters needed to ensure that white space devices can operate harmoniously with existing spectrum users. This means that white space technologies could potentially be launched in the UK towards the end of 2013.

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