The UK Considers UWB
January 27, 2005
The proposed policy could put ultrawideband wireless--currently limited in the UK due to licensed spectrum limitations--to work as it is intended elsewhere, namely for networking and home entertainment.
Last week, United Kingdom telecom regulator Ofcom published its proposed policy regarding the use of ultrawideband (UWB) in the UK, stating its support for the license-free implementation of the technology. UWB is currently used in the UK on a licensed basis for specialized applications like through-wall imaging.
Ofcom's proposed policy is based on the results of an independent study prepared by Mason Communications and DotEcon, which states that significant economic benefit could be derived from the use of UWB in the UK for everything from connecting printers and PCs in a local area network to linking various components of a home entertainment system.
Richard Marsden, DotEcon's project manager for the study, says concerns about harmful interference make UWB a particularly controversial topic. "It affects a wide sway of the spectrum where there's already licensed use," he says. "It's unprecedented to create an unlicensed use across such a large sway of the spectrum."
To resolve those concerns, the Mason/DotEcon study proposes a technical mask, a set of requirements that all UWB devices would have to conform to. That mask, Marsden says, could match the rules set by the Federal Communications Commission (FCC) for UWB use in the United States, or it could be made more restrictive.
The European Telecommunications Standards Institute (ETSI), Marsden says, has proposed a draft standard which allows emission levels of -65dBm/MHz at 2.1GHz. "The reason why it's specified at 2.1GHz is because that's where our 3G operators are located, so that spectrum is of course very valuable," he says.In fact, to further ensure that 3G operators don't face harmful interference, the Mason/DotEcon study suggests adopting an even more restrictive mask that would allow emission levels of -85dBm/MHz at 2.1GHz.
"One possibility is that the mask may be tightened—and I think it's likely that it will be," Marsden says.
The Mason/DotEcon study focused on the potential benefits of UWB, particularly in comparison to other wireless technologies. "Clearly, a big advantage that UWB has over Bluetooth is that it has much higher data rates," Marsden says. "With Wi-Fi, it's a slightly different story. The advantage that UWB might have there is that it is potentially going to be a much lower-cost technology, if it really takes off."
The study results suggest that the benefits could eventually be enormous. "It can generate billions of pounds worth of benefit," Marsden says. "However, that benefit is very much back-loaded over the next 15 years. UWB is not going to have much impact over the next five years, because not many people are going to be using it—but once it starts taking off, then the benefits would be very large indeed."
Still, those predictions are made with the assumption that a restrictive enough mask will be implemented to avoid any harmful interference with 3G—but not so restrictive that US devices can't be used in the UK and Europe. "If Europe went for an even tighter mask and the kit being developed in the States wouldn't work over here, then a huge amount of our benefits would be wiped out," Marsden says.
William Webb, Ofcom's head of R&D, says it's important for the UK and European (EC) regulations to match—though not so for the UK and the US. "We believe that if we achieve pan-EC agreement it will not be necessary for EC and US regulations to match as the EC is a sufficiently large market to generate its own economies of scale," he says.
Webb says the coming months will be crucial. "It's just the beginning in that we have commissioned further studies and we might undertake further consultation," he says. "We will also be working closely with the EC. However, it is certainly significant in that it is the first time the regulator has sought industry views on whether to allow ultrawideband devices in the UK, potentially on a license-exempt basis."