The more communications technologies appear in the high street, the
more bandwidth we all demand. But there is a limit to how many new communications
frequencies can be squeezed from our already overstretched airwaves. The
solution could be to exploit the high frequency, short wavelength end
of the spectrum previously untapped by the communications industry. Unfortunately
no-one is quite sure exactly how high frequency signals behave in the
damp, icy environment of the upper atmosphere. Can we be sure that signals
will arrive where they're needed come rain or shine?
Three new systems all propose to use millimetre waves: Multi-channel
Multipoint Distribution Service (MMDS), the Personal Communications Service
(PCN) and the Mobile Broadband Service (MBS). As yet, planners are reluctant
to exploit these higher frequencies to the full, because they cannot be
sure that current prediction models will hold. In this study, based at
Chilbolton Observatory, researchers are investigating how radio signals
up to 210 GHz attenuate or fade in rain, snow and fog. These results will
help planners to develop new systems and allow them to make confident
predictions about how they will behave.
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The testing range at Chilbolton
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