Consumer demand for interactive digital services is escalating rapidly
across Europe and North America. Services like data transfer and video-on-demand
are extremely bandwidth hungry and discussions are underway world-wide
to find space on the spectrum to support them. One plot on the spectrum
from 40.5-42.5 GHz has already been allocated to what are known as multichannel
multipoint distribution services (MMDS), such as digital TV.
At these frequencies, the local environment can severely limit the range
of a transmitter. Reception is affected by buildings, terrain, vegetation,
scatter and 'multipath', when signals arriving at different times via
different paths interfere with each other. Rain can also cause signals
to fade dramatically.
The purpose of this study was to assess exactly how all these factors
affect millimetre-wave signals in a cellular rather than point to point
system. Broadcast systems such as mobile phones and digital TV use central
transmitters to transmit a signal to all the buildings in an area or cell,
typically between 2 and 5km in diameter. Based on measurements taken in
Oxford, the team aimed to develop statistical planning tools that would
help to predict how 42GHz signals behave in a real urban environment.
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Landrover used for area coverage studies
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