Adaptive Focus
The underlying technology enabling Always-On™ GPS is Adaptive Focus.
In continuous operation, Air’s hardware architecture allows power consumption to be traded dynamically for accuracy – conventional architectures can’t do this. When imprecise measurement is sufficient, huge power can be saved; when precise measurement is required the receiver can instantly snap into focus to provide the same degree of accuracy as any other GPS solution.
Intelligent software algorithms dynamically adjust location accuracy based on the instantaneous needs of whichever applications are running to optimize power consumption.
This is best illustrated by example. A cellphone is running a simple application which will automatically change its ringtone when you enter the parking lot at your office. (Let’s say you enjoy a loud and flowery ringtone on your phone when you are at home; however your colleagues appreciate a quieter, more professional sound when you are at work …). When you are 3km from the office, it is not necessary to measure your location to an accuracy of 1 or 2 metres to support this application. A very coarse measurement can be made to determine that you are not at the office. As you get closer to work, however, progressively more accurate measurements are made until the moment where you enter the parking lot is precisely detected – and the ringtone is changed to the great relief of your colleagues
The net result is a massive saving in power consumption compared to conventional GPS receivers – up to 2 orders of magnitude – allowing the GPS receiver to remain switched on all the time.