At 04:26 AM 6/27/2007, Trevor wrote:
A License Exempt (Part-15) Spectrum Measurement Study was recently carried out for the UK Regulator Ofcom involving 20 sites across England.
The study appears to show comparitively little usage of 2.4 GHz (page 30 of the summary). This is almost certainly down to the locations chosen for monitoring and the short range (< 1000 feet) of license exempt consumer products. Had the monitoring stations been been sited in a typically urban household, built at 20 homes to the acre, I'm sure they'd have picked up plenty of activity.
I find that rather surprising, given my experience. Limiting monitoring to Wi-Fi devices, one doesn't have to go too far to see a wireless network or two (in many cases, one doesn't have to go out the front door to see a wireless network that does not belong to the house!). In a major city, the noise floor literally jumps in this area. Local hams who work in RF comms have shared stories of seeing a major spike in the noise floor between 2.400 and 2.483 GHz when connecting an antenna to a spectrum analyser, and those stories are from 5 years ago, not now.
Even regional towns 2 years ago had significant activity here... :)
And then on top of the Wi-Fi din, add cordless phones, video senders and other miscellaneous gadgets...
73 de VK3JED http://vkradio.com