Originally Posted by Juha

It could but it seldom takes that long. It takes about 12-13 minutes for an unassisted GPS receiver to download GPS almanac and other required info from the satellite. If the last downloaded almanac is relatively recent, and the location hasn't changed a lot since then, getting a first fix is a matter of a couple of minutes or under a minute.

You are describing an assisted GPS. Pure GPS devices (unassisted), or even GPS chips in smartphones don't work like that. GPS readings are accurate in the sense that the (unassisted) receiver doesn't report a "fuzzy" location at first and work its way from there. If there's enough info to calculate a GPS fix, it's done to the GPS specs, no reservations. A pure GPS receiver has no way of telling if a calculated result is accurate or not, as it lacks independent reference data. Devices with GSM/wi-fi have access to such data.

Regarding power consumption: GPS alone is a power hog. From what I've read, GPS receivers in smartphones often use longer intervals in between fixes for this reason. If you use assisted GPS with all bells and whistles, you have a lot of power hungry technologies enabled simultaneously (GPS, GSM, wi-fi and a high resolution colour screen). Whether that consumes more batteries than running an unassisted GPS alone depends on many factors.

Finally, and as a side note, I hope we all can discuss GPS without resorting to personal attacks. If not, the thread will be closed. Thank you.

--Juha, a Forum Mod