The reason why FM receivers are present on smartphones is that they can be used to locate your position by noting a simple thing as signal strength of transmitters. More advanced methods makes use of SNR, frequency deviation and multipath interference characteristics. And the same method can be used for WiFi which of course makes collection of such data very useful for localization purposes where GPS etc isn't useful. Arrival time of a radio signal that is reported to the operator from many devices may also be used for the same purpose.
(Score: 2) by maxwell demon on Wednesday May 21 2014, @06:06PM
Really? I must be nobody, then.
The Tao of math: The numbers you can count are not the real numbers.