Wednesday, May 06, 2009

Ofcom report - Licence Exempt Spectrum Bands

Estimating the Utilisation of Key Licence Exempt Spectrum Bands (here )

There is anecdotal information and discussion that WiFi systems are highly congested in cities and are failing to work in certain locations. We commissioned the design of a novel monitoring system based on smartphone devices with GPS and WiFi capabilities. These were then carried around city centres, including into a number of buildings such as railway stations, where they monitored key beacon signals transmitted from WiFi networks and measured performance parameters. A test network was also built in the laboratory to try to replicate the measurements made.



A survey of IEEE 802.11b/g 'WiFi' usage has been carried out at various urban locations in

the UK. This has revealed a wide variety of problems encountered by users, many of which

are due to causes other than spectrum issues. These include problems with the wired

Internet and device configuration errors.

Where the users' problems are spectrum-related they tend to be due to interference between

devices in the 2.4 GHz ISM band rather than congestion, as was initially believed. (...) 


Ofcom today published three independent reports on spectrum use, availability and interference. The reports can be found here:


·               Capture of Spectrum Utilisation Information using Moving Vehicles:

·               Estimating the Utilisation of Key Licence-Exempt Spectrum Bands:

·               Wide-range propagation model:

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