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Androidfilter: can I use my Android's GPS despite not buying a 3G plan?
June 27, 2014 1:22 PM   Subscribe

I own an old Samsung Galaxy SII Android phone. I've recently cancelled its 3G plan, so now it accesses the Internet exclusively through Wifi. This has apparently caused its GPS function to stop working when it's out of range of a Wifi network, which I hadn't expected. I'd like to resume using it as a mobile GPS device without re-purchasing a 3G plan. Do you know whether this can be done?

For example, I'm considering buying FreedomPop (basically a mobile hotspot that connects to the Internet via 3G and functions as a Wifi network, to which the Android can subsequently connect whenever it's within range). If I were to carry around both the Android and the FreedomPop, would the Android be able to connect to the FreedomPop via Wifi, and therefore be able to track my jogging via GPS and/or provide GPS navigation in my car?

Alternatively, do you know another way that I can regain GPS functionality, while cheaping out on buying an actual data plan?

Anything else I'm overlooking in this plan?

Thanks in advance!
posted by foursentences to Technology (19 answers total) 4 users marked this as a favorite
 
GPS on mobile devices is kind of a misnomer. If I recall correctly, it does not use the GPS satellite network like a standalone GPS device would. Rather, it triangulates your current location by calculating the distance to the nearest 2 or 3 cell towers. This requires a cellular connection, though I don't think any data is used.

Somewhere in my settings (N.B.: iPhone, not Android), there is a message that says "GPS accuracy is improved when WiFi is enabled." I'm not sure why that is, as I don't think WiFi routers broadcast any kind of location information so it could not use your router as a "tower" for location purposes.
posted by tckma at 1:28 PM on June 27


Are you using google maps which needs new maps to be downloaded via an internet connection, or an app like TomTom which doesn't need to be online?
posted by Sophont at 1:28 PM on June 27 [2 favorites]


There's a free app called MapFactor for Android which will pre-download OpenStreetMap data for this purpose. I haven't tested it before. The GPS receiver doesn't rely on the data connection itself, so I assume it's maps and navigation you need, right? Also, I find GPS Toolbox useful for when I can't get a decent signal.
posted by mkb at 1:29 PM on June 27 [1 favorite]


You could get pay-as-you-go data, and if that's all you're going to use it for you don't need much: anecdotally, the downloaded google maps files are 2-3mb for whatever your "local" area is, plus about 400-500k an hour of usage.
posted by Oktober at 1:31 PM on June 27


What app are you using/what behavior are you doing when gps stops working? It might just be that the app you are using is flaking out without data. I have a Galaxy S (no numbers), and have no problem using it as a run tracker. The app keeps the GPS data, and if I'm in the middle of a run, the background of the map (streets, etc) won't update, but the position trail is handled correctly. When I finally get home and look at the map, it looks as I'd expect.

My phone is in airplane mode, with gps and wifi enabled. Perhaps without airplane mode on the GPS is trying to use the cell towers for additional data and possibly having an issue?

OsmAnd is a gps navigation specifically made for offline capability, if that's what you're looking for.
posted by nobeagle at 1:31 PM on June 27


Sygic is another program that doesn't need a data connection. There are quite a few in the Play store!

@tckma: The GPS in phones is pretty standard, just like a dedicated unit. The reason wifi improves accuracy somewhat is that Google collects data on the locations of wifi networks. Your phone will recognize that it can detect the McDonalds wifi you just passed and at what strength, so after running that info past Google, it now knows that you are somewhere on the outer range of that particular McDonalds.
posted by Willie0248 at 1:33 PM on June 27 [2 favorites]


GPS on mobile devices is kind of a misnomer. If I recall correctly, it does not use the GPS satellite network like a standalone GPS device would. Rather, it triangulates your current location by calculating the distance to the nearest 2 or 3 cell towers. This requires a cellular connection, though I don't think any data is used.

This is called 'Assisted GPS' or 'A-GPS'. The Galaxy S2 uses A-GPS...
posted by Fidel Cashflow at 1:34 PM on June 27 [2 favorites]


You can download maps for offline use in the Google Maps app. Zoom out to the area you want to save, then in the search bar type "OK Maps" and it will let you save that area. As long as you start your navigation while connected to wifi, you can drive away and continue to receive accurate driving directions without continued data access.

Also, seconding nobeagle - turn on airplane mode, then manually re-enable wifi and GPS. This will turn off the cellular radios (which are only draining your battery anyway since you don't have active service) and will keep the phone from waiting on a cell data signal that's never coming.

Any running apps or similar that are meant to track your path during running/biking/etc. should work without an active data signal, as long as GPS is turned on - but again, as nobeagle indicated, it may not look right until you are back in wifi range so it can match up the saved GPS data with an actual map.
posted by trivia genius at 1:50 PM on June 27


I have a Moto G, so things might be slightly different, but in the Location settings, there are three options for GPS - Device Only (which uses GPS), Battery Saving (which uses wifi and cell towers) and High Accuracy (which uses all three).

I've also found that I have to re-enable google's location access reporting to get the GPS to work properly, when using Google apps. Maybe try using a different app, to see if the GPS does indeed rely on wifi and cell towers for triangulation. I've just tried GPS Test, and it works with just GPS enabled, in airplane mode. It might be that some jiggling of settings is needed.

As mentioned, I have a different phone and possibly a different version of Android, so YMMV.
posted by Solomon at 2:11 PM on June 27


use CoPilot app
posted by WizKid at 2:12 PM on June 27


You may have some luck trying the strategies outlined in this blog post...
posted by Fidel Cashflow at 2:13 PM on June 27


Look for any of the apps that use Open Street Maps, like OsmAnd+. They download the maps to your phone while you're on WiFi, and they are designed to be used when they're no cell signal.
posted by Mo Nickels at 2:32 PM on June 27


There's a bunch of terms being thrown around here. Let's clarify:


GPS runs off of satellites orbiting the earth. A GPS fix gives the coordinates of where you are and has nothing to do with showing up on a map. This works without any sort of cell/internet connection.

A-GPS uses cell towers to speed up the Time to First Fix. This requires a cellular data connection, but A-GPS isn't needed to determine a location.

GPS navigation needs maps. These can either be downloaded ahead of time (like with the TomTom app or OpenStreet) or streamed via the internet as needed (like with Google Maps).
posted by Nonsteroidal Anti-Inflammatory Drug at 2:57 PM on June 27


This will tell you if GPS is working, no data connection needed. Try it when not connected to WIFI, and it should be clear if your problem is only no maps, or if it's something else.
https://play.google.com/store/apps/details?id=com.chartcross.gpstest&hl=en
posted by defcom1 at 3:14 PM on June 27 [1 favorite]


Yeah, to build on what NSAID says, there are multiple ways your phone can get a location. The first is (true) GPS, meaning that your phone gets location data from satellites. The thing is, getting a fix to satellites usually takes several minutes. Your phone doesn't know where it is prior to getting a GPS fix, so it doesn't know which satellites it should be listening for on your local horizon and has to fish around a bit. It takes a little while to figure that out, but once it does, it can figure out your latitude and longitude. If you use one of the apps mentioned above that download the maps for offline use, this should work find as long as you don't mind waiting to get a location fix, and don't plan on going through tunnels, densely tree-d areas, etc. where you might lose a fix on your satellites.

The faster way to get location is using A-GPS via triangulating your location from nearby cell towers (which necessarily requires a cellular plan for you to talk to those towers) or by looking at the MAC addresses of Wifi access points within range. There are companies that literally drive around mapping out where these MAC addresses are located, so your phone can check in and ask a server where it likely is, given that it can currently detect Wifi with the following list of MAC addresses. Of course, this data lives on a server, not your phone, so without a data connection you can't take advantage of this location service either.

I've previously used FreedomPop when it was WiMax only and eventually cancelled my plan because I just couldn't get service in enough locations. I see that they now offer a hub that uses 3G/LTE on the Sprint network, which should plausibly work fine for your needs, as long as you live someplace that FreedomPop guarantees service.

I guess I would say your options right now are 1) use one of the offline maps apps mentioned above with GPS. It will be slower and sensitive to what's overhead, but it will be considerably less expensive. 2) Use the FreedomPop option, which should work fine as long as your are going places where the FreedomPop is within range, but you'll have to pay FreedomPop. I'm curious whether this is a better deal than just unlocking the S2 to run on Ting or one of the bring-your-own-phone carriers and just purchasing a low-end data plan. But, only you can answer that question depending on your needs, local availability, and the particular S2 phone you have (GSM vs CDMA, etc.).
posted by wondercow at 3:45 PM on June 27


A-GPS does not triangulation of your location from nearby cell towers, or WiFi. A-GPS uses a network connection to consult servers for information that allows it reduce the amount of data that needs to be collected from satellites to get a good GPS fix, which saves power, and reduces the time needed to determine location.
posted by Good Brain at 5:06 PM on June 27


...there is a message that says "GPS accuracy is improved when WiFi is enabled." I'm not sure why that is, as I don't think WiFi routers broadcast any kind of location information so it could not use your router as a "tower" for location purposes.
Google swept up every SSID and MAC address they could while sending the StreetView cars around, so the routers don't need to broadcast their location info to help because Google already knows exactly where they are. Your phone doesn't have to connect to a wifi network, just report what MAC addresses it can see from where it is. In this way they are effectively using everyone's router for location purposes.

Samy Kamkar talks about using this for nefarious purposes:
"... if I can obtain the user's router's MAC address in any way, regardless of browser, nationality, or age, I can typically determine their location and show up at their place with pizza and beer later that night."

posted by quinndexter at 4:32 AM on June 28


I have a Galaxy S2 (now using the SuperNexus ROM, but that doesn't matter). The GPS is a GPS. Forget about the A-GPS nonsense. As far as I remember, the A (assisted) means that it uses the wifi or cell location to get a fix more quickly...I don't think the Galaxy S2 uses that.)

Google maps wants to work on-line (that's why you need to be connected) and it will let you cache (store for later use) one small map for later use.

Here are two free (lite versions) that enable you to download large (statewide or world) maps:

MapsWithMe

OsmAnd

I have the paid version of OsmAnd, and it enables me to download covering the entire world. The search function is not great. The lite version (free three areas); upgrade to paid is about $6.00.

MapsWithMe free seems to permit unlimited download of maps, but some features require the paid version, which is about $5.00. Uses the same worldwide set of open-source maps as OsmAnd. I will probably spend the $5.00 to upgrade soon.

You do the map downloading over WiFi (I have NO other data plan) and from there on you can be anywhere in the world and you will know where you are, provide you have previously downloaded the map for that area.

BTW I don't think either gives you voice navigation, but there are other more expensive apps that do that.
posted by mbarryf at 6:10 AM on June 28


Seconding WizKid - CoPilot will do what you want without a data plan, just download the maps ahead of time via WiFi. It does cost money though.
posted by rfs at 2:23 PM on June 28


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