[pct-l] smartphone as GPS

[Eugene Leafty]

Does this require a data plan?

-----Original Message-----
From: pct-l-bounces at backcountry.net [mailto:pct-l-bounces at backcountry.net]
On Behalf Of David Ellzey
Sent: Monday, October 25, 2010 2:02 PM
To: pct-l at backcountry.net
Subject: Re: [pct-l] smartphone as GPS

A few people have indicated that smartphones use cellular tower
triangulation and not satellites. This is not entirely accurate, every
smartphone I know of uses what's called Assisted GPS, or AGPS for short.
Whereas a normal GPS chip takes the signals from satellites and calculates
position, an AGPS chip only records the signals and sends that data to an
online server for calculation. This means that you MUST have a good wireless
connection for the AGPS to work. This is the disadvantage, especially when
in the backcountry.

BigToe