A spectrum of opportunities

The digital switchover offers possibilities for technology developers. Siobhan Wagner reports

Rescue aid: High-speed networks could help firefighters
Rescue aid: High-speed networks could help firefighters

The digital switchover has been hailed by some as a broadcasting milestone of greater importance than the introduction of colour TV. And while it lacks the razzle dazzle of the colour revolution – there is no moment comparable to Dorothy first setting out on the Yellow Brick Road – the government’s plan to turn off analogue transmissions and transition all televisions in the UK to digital-only receiving devices by 2012 could have a major impact on technology, the economy and society in general.

Research conducted by regulator Ofcom has found that already 90 per cent of UK homes have at least one television or set-top box capable of receiving digital broadcasts.

Once the analogue-digital transition is complete, Ofcom anticipates auctioning off the freed-up radio spectrum in 5MHz lots. This is likely to happen around 2010. Telecommunication firms will then begin muscling into position to own a portion of these highly valuable frequencies.
The spectrum of this so-called ‘digital dividend’ is particularly attractive because it is in the sought-after UHF (ultra-high frequency) band in the frequencies 470-862MHz. The 800MHz range is likely to be divided among three UK mobile operators, while the use of the rest of the spectrum remains speculative.

Lee Sanders, partner at telecoms consultancy firm Analysys Mason, said the 800MHz frequency band has slightly less bandwidth than higher frequencies but much better propagation characteristics – meaning signals travel further.

‘So if you’re going to roll out a network, whether it be for broadcasting or for mobile telecommunications, you can do it with fewer base stations, which means much lower costs,’ he explained.

Sanders believes the wider coverage of these frequencies will eventually mean the entire UK – including rural areas – will have mobile broadband. Thus, making the government’s ‘Universal Service Commitment’ of giving access to at least 2Mbps (megabits per second) in every UK household by 2012 seem more plausible.

As it currently stands, more than one in 10 households in the UK do not have access to a 2Mbps connection. The newly available spectrum is also likely to lead to the nationwide roll out of a next-generation mobile network known as 4G or Long-Term Evolution (LTE), which will succeed 3G and 2G standards in the telecoms industry.

Prof William Webb, head of research and development at Ofcom, said these mobile networks would be similar to 3G and 2G, but offer much higher data rates.

‘Like all these things, the data rates that are quoted are rarely achieved in practice, but people are talking about data rates in some cases as high as 100 megabits per second,’ he said. ‘I think in practice that will translate to rates that are more like 10 megabits per second, but nevertheless that’s still substantially faster than existing 2G and 3G systems.’

Webb said Ofcom cannot say for sure what future technologies will benefit from the 4G network, but the regulator tries to make it as flexible as possible to deploy them.

‘We do look for the technologies just to make sure that when we package up the spectrum for auction we don’t inadvertently exclude certain technologies,’ he added. Webb said 4G will be the basis for a variety of inventive applications. ‘Trying to guess what, is like trying to guess what will be the top seller in the Apple App store next week,’ he added.

One of the most likely differences consumers will notice is the ability to watch streaming video such as the BBC iPlayer on mobile devices. Webb said trying to watch that on a laptop running on 3G would be nearly impossible and it would lack clear resolution. ‘Whereas with 4G, it would be well within the capability to do that and it could even download high-definition video within those data rates,’ he added.

As to what happens to the rest of the spectrum, below 800MHz, is uncertain. Webb said the 600MHz range could be used by broadcasters for more high-definition content. ‘It’s also possible that it might be used for a range of specialist-type systems,’ he explained. ‘For example, the emergency services have expressed that they could use the spectrum to build their own broadband network. So the police would have a high-speed data network that they can use when they need to transfer data around, or so that firefighters in burning buildings can quickly access building plans and download those to devices that guide them around the building.’

Webb said frequencies below 600MHz, in the 400MHz range, could be used for some medical devices. ‘We came up with one or two specific applications where having specific spectrum for healthcare would seem sensible,’ he added. ‘Those are broadly to do with where you might have an implant that administers a drug within your body that was controlled by a radio signal.

‘Clearly you don’t want interference in that case to stop it working or make it malfunction. So there have been some calls for more spectrum to clear out the 400MHz area where there is a very small amount of spectrum already dedicated to medical devices.’ Webb said that other devices such as heart monitors that send signals to devices in the home and to healthcare providers could benefit by using Bluetooth in the existing spectrum or cellular networks.

“The coverage of these digital frequencies could lead to UK-wide mobile broadband”

Lee Sanders, Analysys Mason

While the UK is waiting until 2012 to turn off all analogue television signals, other countries such as the US, the Netherlands, Finland, Germany, Luxembourg and Sweden have already switched over. The US has awarded frequency lots in the 800MHz range to mobile networks this year and companies have unveiled plans to roll out 4G networks across the continent in 2010.

The awarding of parts of the UHF spectrum on the European continent will require agreements between countries as radio waves are not bound by national borders and risk interference.

The European Commission (EC) released a communiqué in October calling for harmonising the technical conditions for using the 790-862MHz sub-band. This would allow mobile service providers and developers of wireless devices and applications to do business across borders. It would also mean consumers would find it easier to use roaming services as they travel across the continent.

The approach would be similar to the ones taken for GSM mobile phones in the 1990s. The EC has also called on EU member states to complete the analogue switch-off by 1 January 2012 as a measure to help beat the recession. It estimates that coordinating the allocation of the newly freed airwaves to new services across Europe could give the economy a boost of £20bn (£18bn) to £50bn.

eanwhile, in the UK, Ofcom estimates the increased coverage and services from the freed spectrum could benefit the economy by £5bn to £10bn in total over 20 years.

The economic benefits would hopefully not just be felt by telecoms companies. According to Lee Sanders, the financial gains of releasing UHF spectrum to mobile operators could trickle down to consumers. ‘The low-frequency spectrum reduces the cost to cover areas and using it could lead to reduced costs for services and hopefully reduced costs for consumers,’ he added.

new age of communication

The switch from analogue frees an unprecedented amount of spectrum

  • Located between 200MHz and 1GHz, this spectrum band offers an excellent balance between transmission capacity and distance cover
  • While the 800MHz range will likely be divided among three UK mobile operators, the use of the rest of the spectrum remains speculative, and presents opportunities for developers
  • The 600MHz range could be used by broadcasters for more high-definition content, while the 400MHz range holds promise for the developer of wireless medical devices
  • The government claims that its Digital Economy Bill, announced in the Queen’s Speech, will ensure a communications structure fit for the digital age