Saturday, September 25, 2010
Can you use the GPS on your Android phone in Airplane mode? This question frequently comes up, especially for Android users hiking with offline topo maps in the backcountry with spotty coverage.
The benefits of using Airplane mode in backcountry trips are mainly for battery life. Turning off unneccessary signals is a great way to conserve battery life. When you are out hiking where your Android phone gets little or no cell coverage anyway, there's no use in your phone eating through battery life just trying to get a signal. And if you aren't going to be talking on the phone, you probably don't need bluetooth for your bluetooth headset. And since you won't run across many hot spots in the woods, you can leave wifi off too.
So by turning on Airplane Mode, you can eliminate battery use by cell signal, bluetooth, and wifi. But will the GPS work?
For me, the answer was yes. I did this with my Nexus One, and had no trouble turning on and off the GPS and got some great battery life. The first fix took less than a minute, and subsequent fixes took less than 10 seconds. The longest time to fix was about 2 minutes under heavy tree cover after 24 hours without using the GPS.
I asked about Airplane Mode and GPS in my last newsletter, and the results were staggering. It only took a handful of responses to establish a definite trend.
HTC vs Motorola
If your device is made by HTC, including the Nexus One, Droid Incredible, Evo, and many others, you probably said this:
My GPS works just fine in Airplane Mode.
If your device is made by Motorolla, including the Droid 2, or Droid X, you probably said this:
My phone had trouble getting a fix, or never got a fix, without the cell signal on, even if the signal was weak. After the first fix I could generally turn it off and then navigate okay.
Those who reported this condition were often unsure if they would get a fix without cell signal if they waited long enough.
Do either of these scenarios sound familiar? I don't have enough data to know what Samsung phones do yet.
Unfortunately, I know what is likely happening with the Motorolla phones. They are using Assisted GPS, also known as A-GPS. By itself, this is a good thing, and allows you to get a faster fix when network coverage is available. Unfortunately, the idiots at the phone manufacturer haven't done a good job of making it work without cell coverage. This is not an unusual task. Standalone GPS devices and even bluetooth devices have been able to get a fix in less than a minute for several years now, and they've never had cell coverage.
Does anyone live near Motorola Headquarters? I'd like to stage a protest.
Don't blame BackCountry Navigator, or any other Android App, if you can't get a quick fix in airplane mode. This is appears to be in the hardware, or OEM specific code.
This isn't the worst thing phone companies have done. Not too long ago, Verizon wanted to lock out the GPS in a Windows Mobile Phone to all but "approved" apps, in order to sell you their VZNavigator at $10/month.
Hopefully, manufacturers will figure out sometime, we want to use the GPS in our Android phones as a GPS. Just like some antenna makers needed to figure out that some people use their iPhone as a phone.