[OpenTRV-dev] Mobile phone detector

Kevin Wood kevin at the-wood-family.com
Thu Nov 5 14:44:53 GMT 2015

> - Do you have any idea what the most popular bands are in London?

Not directly. One would probably expect the higher frequencies to be more
commonplace as their natural characteristics better suit small cells in
dense urban areas, but frequencies are chosen for political reasons as
well as technical.

> - The higher frequencies you mention have fairly small wavelengths. How
> feasible would it be to use a directional antenna to discriminate
> between, say mobiles directly under the bus shelter and those nearby/the
> cell site?

Well, smaller wavelengths generally mean you can incorporate a more
directional antenna into a given space, so arranging it to "beam" into the
occupied area of the bus shelter from, perhaps, one corner might well be a

> - As far as I'm aware, a lot people walk around with their wifi left on.
> Would it be more practical have a similar system checking for wifi
> connections instead/as well?

Wi-Fi is possibly more of a challenge given the lower TX power involved.

> I guess it would be worth going around bus stops with a spectrum
> analyzer and a couple of different antennas...

Yes, indeed.


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