20/04/2005

'Standards wars' threatening Ultrawideband - ZDNet UK News

'Standards wars' threatening Ultrawideband - ZDNet UK News

Ultrawideband (UWB) is a really interesting technology, WiMAX is actually a UWB system but only uses a small subset of frequencies.

UWB works by sending signals over a large section of spectrum so it could work from <1GHz all the way up to 100's of GHz. It's clever because it uses a lot of error correction and splits the data up over lots of parts of the spectrum. So a "bit" of data may actually be sent over 100's of frequencies simultaneously. A receiver "listens" to the whole set of frequencies and puts the data back together again. If any particular frequencies aren't received (they may be absorbed by walls, or reflected etc) then the receiver can still reconsitute the data as it's spread across a large number of frequencies. This does mean data rates are reduced, but the system is highly resilient.

In the US the Federal Communications Agency (FCC, similar to the UK's Ofcom) has allowed the US of UWB for short range communications, but at very low power. This allows UWB to be used as a replacement for wires and give very high data rates (100's of Mb/s). As the power is so low, anything that isn't a UWB system will just assume the signal is background noise and ignore it. If other systems are using some of the same frequencies and drowning them out, again it doesn't matter as the UWB system will have spread the data over many frequencies, some of which wont be being used by anything else.

Ofcom originally inferred they were in favour of UWB and would allow its use in the UK, but they still haven't announced a decision, which is angering some UK players who would like to see it adopted here and produce UWB systems.

UWB can also be used in high power applications, but these would likely used licensed bands.

A very interesting application can be for cable TV, a US manufacturer has produced a UWB specifically for this and can send data down a co-ax cable at over 400Mb/s, which would support many channels of TV and Internet and voice. It would also not degrade so much as current CATV systems do with the more people in a street getting service.

UWB is a pretty exciting technology, it just needs Ofcom to clear the way.
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