Unprecedented move will put Ireland at least two years ahead in dynamic spectrum access research, writes Karlin Lillington

A Trinity College-based group is to be the first research centre in the world to carry out real time experiments in the cutting edge area of dynamic spectrum allocation. In order to do so, it has received the first ever "research grant" of radio spectrum from the communications regulator.

Such a donation of space on the airwaves for research is unprecedented and is expected to attract many of the most innovative information and communications technology companies to do research in this area in Ireland, say informed observers.

In effect, the grant from ComReg turns the entire country into an experimental ground for new technologies and services.

The research will be done by Trinity's Centre for Telecommunications Value-chain Research (CTVR), a Science Foundation Ireland and IDA-funded group comprising eight Irish universities and Bell Labs Ireland Research Centre.

Currently, licensed holders of spectrum - such as mobile phone operators or radio stations - can only use the spectrum they have been allocated by national regulators.

With dynamic spectrum allocation, licensed operators could "spectrum hop" across the allocations, using unused or underused spectrum. "Because Ireland is an island, it can be a playground for spectrum," says Dr Linda Doyle, who leads the spectrum research group.

"It is incredibly forward thinking of ComReg as there isn't another regulator in the world that has been prepared to grant spectrum like this."

With the rapid development in the past two decades of electronic and digital devices that require spectrum - everything from home wireless networks and garage door openers to mobiles and Bluetooth-enabled laptops - demand has become increasingly strong to rethink spectrum allocation.

"Spectrum is considered a scarce resource," notes Dr Doyle. "But some of that scarcity is actually a false scarcity, because spectrum isn't efficiently used."

She shows a chart of spectrum use in London over a 24-hour period, with heavy use marked in red bands, and blue bands indicating no activity.

Perhaps 60-70 per cent of the chart is blue. The American Federal Communication Commission (FCC) has stated that around 90 per cent of spectrum is underutilised, she adds. Some of the congested areas indicate usage in the more desirable bands.

Certain frequencies are valued by certain industries because they enable better signal quality or strength - mobile and television operators prefer this spectrum - or conversely, enable a signal to be received over a longer distance - shortwave radio broadcasts - where distance rather than quality is valued. But even with those very congested bands, not all are used at capacity all the time, and spectrum-hopping is seen as a possible solution as more devices and services clamour for a slice of spectrum.

Dynamic spectrum access would also help resolve some of the technical difficulties in maintaining a smooth mobile signal when a conversation carried on the latest 3G networks needs to be handed off to the standard GSM network - for example, when one person talking on a 3G phone passes out of the range of more geographically limited 3G networks.

The difficulty to date has been that no one has been able to experiment with real, live spectrum, says TCD Prof Donal O'Mahony, director of CTVR.

As regulators have been unwilling to hand over spectrum - an important national resource and also a lucrative one, going by the prices paid for mobile operator licenses - the only experimentation to date has been on computer simulated models.

Ireland has the advantage of using less of its available spectrum than some countries, and because it is an island, of having spectrum cleanly isolated from that in neighbouring countries, he says. ComReg has freed up 50 megahertz (MHz) of spectrum for an experimental software radio licence for CTVR, an enormous range considering the entire FM radio broadcast band in Ireland is 20MHz.

The allocation is generous and an international first. When, at a recent conference, Dr Doyle mentioned the pending grant of spectrum to the assistant secretary for communications and information of the US National Telecommunications and Information Administration, "he nearly fell off his chair," she says.

As part of the dynamic access project, a team working under Dr Doyle at CTVR has developed what it terms a "software radio" - "a bucket of components that can be put together in many different ways," says Dr Doyle.

This makes the software component highly flexible and would enable a single device to be marketed in multiple geographies where different services might be available.

Right now, devices generally have to be manufactured separately for each region, at greater cost and lower efficiency. The other piece of the puzzle is the hardware used to receive the radio signals, and CTVR has developed hardware for the experimentation as well.

Prof O'Mahony says he expects the project to attract much international attention. "Spectrum access is a burgeoning area right now and I can see companies locating here to experiment."

Because of the time needed to build up research expertise and work out spectrum grants from regulators, he also believes Ireland will now have a lead of at least two years over other international groups working in the area, assuming any other regulator is willing to make a similar spectrum allocation.

"We also have commercial possibilities within the centre itself, for example for spin-off companies or for larger partners to become involved and commercialise the research," says Prof O'Mahony.

"In the case of Ireland, I think one country can make a significant impact in this area," says Dr Doyle.