Mapping Hacks

Preface

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Location sensing will eventually be spectrally independent (that is, not lim-

ited to the Wi-Fi spectrum). Software that listens to television and radio sig-

nals to calculate location is already beginning to emerge. Radio and

television transmission towers have publicly known locations; the new digi-

tal television broadcasts also have a digital timestamp. This timestamp

allows devices to triangulate location by comparing timestamps, much like

the ones GPS satellites provide from orbit, and commercial interests are

already using this technique to provide geolocation services. Whatever sig-

nals a device is listening to, it will eventually be able to figure out where it is

and whether the signals are radio, Wi-Fi, cellular, GPS, or television.

Ultimately, location-sensitive applications might use microsensors and RFID

tags that rely on both active client software and passive techniques. These

small integrated circuits will be connected to antennas and respond to an

interrogating radio signal. They will supply simple identifying information,

including location coordinates. When queried, the RFID tag will return such

location information as latitude and longitude, effectively serving as a digi-

tal survey stake.

All this means that, at least, one might need never be lost in a strange place

again—unless one wants to be, by turning off the electronic device. Cer-

tainly, it seems that the ...