03-23-2011 02:58 PM - edited 03-23-2011 03:04 PM
@thesmileman, I'm puzzled by that. GPS requires only a receiver, to pick up time signals from the satellites. While on some devices (like my old Android) having a GPS turned on all the time sucks battery power, it's not necessarly inherent in the technology and the WiLink 7 chip used for this in the PlayBook promises much improved power consumption than other solutions. I'm not sure your concern is warranted yet.
Edit: removed word "passive". The receiver doesn't transmit, but it's certainly not merely "passive".
03-23-2011 03:26 PM
Rather than debate something about which we have few facts, I'll merely post a link to the WiLink 7 docs and let you decide for yourself whether to be patient and see how it works on the real hardware, or to anticipate problems which may not exist.
06-14-2011 04:50 PM
This is an old thread, but to tie up one loose end, now that we actually have a working GPS, here's some data on power consumption.
A PlayBook doing nothing, on standby, uses about 50mW of power on average. (I think the units I'm seeing are mW... we could also just call it "power units" and treat the values as relative... makes no difference here.)
Add in a GPS tracking app which requests 1s updates, receives them every 1.86s on average, and writes them to a CSV file, and it consumes about 230mW on average.
Run the same app with GPS muted and a fake timer generating fake GeolocationEvents, and it apparently uses no more than the idle PlayBook, meaning running the GPS (at what looks like the max sample rate) takes about 180mW extra power. That doesn't appear particularly significant... you could run a GPS app for over 3 days non-stop at that rate (again, screen off).
For comparison, merely having your screen and backlight turned on, at a minimum backlight level, but doing nothing uses more than 1600. Playing a Flash video on the CNN web site, with full backlight, appears to be near 4000.