20 April 2009
Dr David Cleevely, telecoms expert and chairman of Cambridge Wireless
Dr David Cleevely, telecoms expert and chairman of Cambridge Wireless, discusses a wireless technology breakthrough that he says will have as much impact as the Internet revolution of the 1980s.
Q: How do you anticipate a step change in wireless technology?
DC: Just as we have become used to having microprocessor chips in everything from the fridge to the door bell, so every individual will own hundreds of radios, all working together to do fantastic things. We are on the edge of the same kind of transition that the telecoms industry was facing in the 1980s but it didn't really know it.
Q: How exactly will this change happen?
DC: Originally it was believed that to make wireless transmissions we needed high radio masts, to broadcast at high power and use the same spectrum all the way to the end user. This limits the amount of traffic the system can accommodate. A breakthrough came with the idea of cells, each containing a full range of spectrum, so the smaller the cells, the more mobile phone conversations you could make. This has resulted in the situation we have now – with thousands and thousands of people able to make calls within a square kilometre. Cognitive radio builds on this breakthrough by being both intelligent and polite. It has a system of simple rules to see who is doing what and how it can interact with them. Introduce the concept of cognitive radio and you start to get a system which can react continuously to the amount of activity, just as the Internet does today.
Q: Cognitive radio technology is already being used to some extent in 3G and in defence applications, but what are the other potential uses?
DC: The potential for cognitive radio is exciting. If the devices can intelligently negotiate with each other and also 'hop' to other frequencies as required, then the current problems of compatibility and interference will be largely overcome. The other element of the equation is mesh networks. This is where radio devices connect with each other instead of via a base station, creating the opportunity for comprehensive wireless networks to be created within homes, buildings, or on board a ship, for example. In a mesh network, every radio acts as a switch for every other radio. They talk to each other in sequence. 3G devices can already work out where others are, and if you have further development of cognitive systems, radios will twitter together to self organise into a network – and job done!
For an engineer this is a very elegant solution as it doesn't require you to optimise just for one specific set of conditions, which is an enormous benefit. At the moment the position of base stations needs to be carefully calculated. All you need is for a tree to grow between them and reduce the signal strength or a new building to act as a reflector, spoiling your carefully laid plans. These systems will simply work out how to solve these problems themselves. The next step is the really exciting one. These little intelligent radios only require extremely low power. Vibration or light will be sufficient to charge them and they can be located wherever you want them. This is good news for the developers of assisted living and healthcare applications. Ants only have a few rules but they can achieve sophisticated operations. I think these radio devices will also be capable of great things that have yet to be imagined.
Q: Are there any obstacles in the way?
DC: It turns out that people aren't actually prepared to pay even a tenth of the price that was paid in the 3G auctions. The value of spectrum is going to go down and down and down. And the reason is the architecture that I've been talking about. There is no shortage of spectrum – shortage only exists because of artificial constraints and restrictions due to regulating what spectrum can be used for.
It's always a trade off. Operators will choose between deploying more equipment or buying more spectrum. If equipment is cheap, then it's not worth paying much for extra spectrum. Equipment and transmission are getting cheaper, and technology is becoming more sophisticated. Once regulators stop saying what spectrum can and cannot be used for, there's no reason to pay a lot for a once in a lifetime opportunity to offer a service. If someone wants too much for spectrum, use what you have got more efficiently by deploying more kit. The spectrum price will then fall.
But there is a wrinkle in all this. If you slice up the spectrum into too small chunks, they become more difficult to use. You need big slices available for this market to work. Problems are also generated by other things – for example the UK spectrum will be different from the US.
Q: Which markets will benefit?
DC: There will always be a multiplicity of market segments and they will all require handsets aligned to their requirements. There are nearly 500 different kinds of mobiles in the UK alone. Perhaps the best example of the range of possibilities is the Apple iPhone, something which can almost supplant for a lot of purposes the PC or the laptop. It has a fantastic interface and it's applying some interesting business models. But, despite that the iPhone is not a perfect gadget, it's radio is nothing like as good as, say, a Nokia, which means there are lots of places you can't make or receive calls. In the long-term these new technology developments will open up even more opportunities than we've seen or can dream of.
Engineering is about making amazing things at the lowest possible cost. We use the results of engineering all the time, but I don't understand why, particularly in the UK, we don't really appreciate how fantastic some of this stuff is and what engineering does for us. The sheer genius of what's inside an iPhone – or any other mobile – is amazing.
The forthcoming Cambridge Wireless international conference – 'The Future of Wireless' - takes place at the Imperial War Museum, Duxford, Cambridge, on April 30th and May 1st.
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