White space broadband: your questions answered

The telecommunications watchdog, Ofcom, is running a trial with partners including Microsoft, Google and BT to use new 'white space' technology for mobile broadband and connectivity
Ofcom's white space technology trial offers the capability to provide wireless broadband to connected devices and internet access to hard-to-reach rural areas.
Ofcom's white space technology trial offers the capability to provide wireless broadband to connected devices and internet access to hard-to-reach rural areas. Photograph: Murdo Macleod

Ofcom has announced Europe's first trial of new "white space" technology which could enable new high-speed mobile broadband and the internet of things.

"Spectrum is the raw material that will underpin the next revolution in wireless communications," said Ofcom's chief technology officer Steve Unger. "However, there isn't an unlimited supply of spectrum to meet the extraordinary demand of our ever expanding internet-connected society."

The hope is that white space technology - explained below - will help provide much-needed extra spectrum and wireless communications to provide the backbone to support the billions of smart, connected devices that are looming on the horizon.

What exactly is 'white space'?

White space is defined as the unused frequencies allocated to broadcasting services but that are left unused in particular areas of the country. For digital TV in the UK, these chunks of spectrum are left open as buffering gaps between the high-powered transmissions carrying broadcast TV to avoid interference.

The white space frequencies vary by region, but lie in chunks of spectrum between 470MHz and 790Mhz. The size of the frequency gaps, and their precise frequency, varies too - meaning there is no single white space frequency that can be used around the country.

Devices such as mobile phones and tablets could use the free spectrum by knowing which frequencies are available, at what power levels, and at which times of the day in a particular location.

Ofcom intends to have white space database providers inform devices on the ground which chunks of spectrum are available for use in their vicinity to allow interconnectivity without interfering with the transmission of digital TV.

What can it enable? 

Opening up white space to lower-powered devices provides more wireless spectrum for data transmission to support a large range of services and devices.

For example, white space could be used to provide wireless broadband internet access, similar to Wi-Fi but over much longer distances, to mobile devices like tablets and phones. It could also be used as an extension of fixed-line broadband to reach places that aren't connected via cable without resorting to line-of-sight technology such as satellite or microwave broadband.

The white space spectrum could be used for connecting devices as part of the "internet of things" too, where infrastructure becomes intelligently interconnected allowing collected information to be passed between traditionally disconnected devices and hardware - something often referred to as machine-to-machine communication or M2M.

For example, cars could communicate with each other, warning drivers of stationary vehicles along their path that would otherwise not be visible due to traffic. Cars could also connect to the road infrastructure for traffic management, allowing intelligent adjustment of speed limits and traffic patterns to eliminate the stop-start traffic congestion often seen on motorways and ensuring a higher average speed and shorter average journey times.

What uses does white space technology have already?

The UK is the first country in Europe to look at utilising white space spectrum. But the United States and other countries have already started using it.

A municipal "smart city" wireless network was established in Wilmington, North Carolina in the US in 2011. It used white space spectrum to connect the city's infrastructure and public services, allowing officials to turn the lights on and off in parks, monitor water levels and quality, as well as provide public Wi-Fi to certain areas.

In April 2012, Microsoft and a consortium of internet service providers conducted a white space trial in Cambridge, UK. That involved a live stream of HD video from the internet to an Xbox 360, as well as a live video chat between two wirelessly connected Xbox 360s using Microsoft's Kinect system.

What's happening now?

Today, Ofcom announced the participants in a white space trial that will run over the next six months in various parts of the UK.

Around 20 public and private organisations, including Microsoft, Google, BT, Neul, Meld, and the Department for Transport will be involved in the trials ranging from high definition TV broadcasts and wireless broadband, to traffic flow monitoring.

Microsoft is running a trial in Glasgow to provide free wireless internet access to residents in certain areas of the city, while also linking a network of sensors to create a "smart city" with the University of Strathclyde.

Along the A14 between Felixstowe and Cambridge, the Department for Transport will work with BT and wireless technology specialist Neul to test the use of white space for car-to-infrastructure communications, monitoring traffic conditions and providing information to help reduce congestion and improve road safety.

Click4Internet, an internet service provider based in Hampshire, will also look at trailing the use of white space spectrum as a method for providing an alternative to fixed-line broadband in hard to reach rural areas.

What could it mean for you?

Connectivity is at a premium right now, and the demand for internet access is set to skyrocket, with an estimated 50bn internet-connected devices globally by 2020, according to data from Cisco.

The use of white space will provide another resource of bandwidth and invaluable connectivity, while not having to rely on traditional mobile phone networks. It has the potential to connect both mobile and fixed devices to the internet where Wi-Fi cannot reach.

Wireless broadband provided over white space spectrum will travel long distances and through solid objects and foliage, potentially providing better wireless broadband coverage in traditionally signal-poor areas, due to the use of low frequencies in the sub 800MHz range. 

It can also to realise the idea of the internet of things, creating 'smart cities' by connecting a network of sensors around us to help our towns and cities better adapt to our changing needs throughout the day.

The trials taking place over the next six months across the UK are just the first stages of unlocking the white space potential. We'll know more about what works well and what doesn't by spring 2014.

Today's best video