How does "Find my frinds" actually work?

Question

Level 1

12 points

How does "Find my frinds" actually work?

Hello,

I've been browsing these and many other forums, but I still can't figure out how this app really works. On my iPhone I can't track my friends. They always show up with the last known location or "location unavailable", but never in motion.

So ... how does the app do what it does? Does it use the cell network or the GPS to determine where I am? Do I need WiFi or a cell plan with internet access to be trackable? I understand that I need internet access to track someone. But to be tracked?

To clarify, I'm using my iPhone with 3G and cellular data turned off, because I'd have to pay by the MB to use the internet. It's a prepaid plan And it works fine with me because most of my time I spend near a WiFi spot, so there's no need for any internet plans. To get the most out of my battery I also have Background App refresh turned off, as well as most location services (incl. all the system services) except for Weather, Find my friends and Find my iPhone.

AM I doing anything wrong or does Find my Friends need an internet connection to function? Or do all "friends" need to have the app open? In short: How does it work?

I appreciate any hints, links and advice. Thanks.

Posted on Jul 11, 2014 1:44 AM

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Answer 1

tickbite71 Author

Level 1

12 points

Jul 11, 2014 12:31 PM in response to IdrisSeabright

Hello Meg, thanks for the response. I can see that I need an internet connection, i.e., a cell data network, to see the maps and be able to tell where my friends are. But why is it necessary to be trackable? My phone is sending out a cellular signal in any case; why doesn't that suffice for informing others of my approximate location?

I did a little experiment: If I turn on cell data, I can find my friend's phone with an accuracy of about 100 meters. If I add 3G, accuracy improves to maybe 50 meters. If I add WiFi, I can pinpoint people to their living rooms (although to be fair, the location in each of these cases is a bit off from the actual position of my friend). So turning on all these services increases accuracy. But why can i not find my friend at all if I turn on all three of these? Shouldn't the cell phone signal alone give me an idea of where the phone is, even if accuracy goes down to something like 500 meters?

On a side note, in Find My iPhone, the circle turns grey without these three services, so apparently at least one of them (and not only 3G) is necessary for this app to function at all. I don't understand why ...

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Answer 2

Mar 18, 2017 6:15 AM in response to tickbite71

Phones are equipped with GPS receivers to capture location data from satellites. This is stored in a memory location in your phone. FInd Friends, Maps & other location based apps read this data to locate you.

When you use Find friends to request a friend's location, the friend basically gives you permission to read his location data from his phone's memory. This location data needs to be transferred to you by Wifi or Mobile data. Once permission is given, the find friends App in your friend's phone has no role in passing his location data. However, if he logs out or uninstalls the application, all permissions are automatically revoked.

In addition, location can be got not only from satellites, but, in its absence, by wi-fi. By having a huge constantly updated database of routers and and their signal strengths with the corresponding gps locations (whenever gps is available), it is quite easy to locate a phone even when gps is NOT available with the help of available router signals.

Hope this helps.

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Answer 3

FelipeV

Level 6

10,636 points

Jul 11, 2014 4:21 AM in response to tickbite71

They need to have the app installed and running. And they need to accept your invitation asking for them to allow you to follow them. The app uses location services, cell and wifi data to determine yours (and the "followee's" positions).

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Answer 4

tickbite71 Author

Level 1

12 points

Jul 11, 2014 10:38 AM in response to FelipeV

Thanks, Felipe, at least this explains why it's not working for me. I'm still wondering how this app works. Does a phone send out its position by WiFi? If location services are turned on, and I oviously have a signal, why does the app require wifi to determine my location? Using navigation software, I would be able to determine my position completely without the cell network ...

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Answer 5

FelipeV

Level 6

10,636 points

Jul 11, 2014 10:42 AM in response to tickbite71

Wifi is not needed but helps as it makes the position more accurate.

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Answer 6

tickbite71 Author

Level 1

12 points

Jul 11, 2014 11:52 AM in response to FelipeV

But cell data is needed then, not just for accuracy? Because otherwise I still can't see why I'm not getting any movement at all on my friends' phones.

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Answer 7

Jul 11, 2014 12:05 PM in response to tickbite71

Cellular data is needed for the actual maps your phone downloads. Without them, you'd just get GPS co-ordinates.

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Answer 8

Jul 11, 2014 12:41 PM in response to tickbite71

tickbite71 wrote:

Hello Meg, thanks for the response. I can see that I need an internet connection, i.e., a cell data network, to see the maps and be able to tell where my friends are. But why is it necessary to be trackable? My phone is sending out a cellular signal in any case; why doesn't that suffice for informing others of my approximate location?

The phone is sending all of the information about your location over cellular data. Your friends aren't connecting to GPS satellites to see where you are. They're getting the information from Apple's servers. Your phone can pinpoint its own location using WiFi/Cellular/GPS but, to transmit that information, it needs cellular data.

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Answer 9

tickbite71 Author

Level 1

12 points

Jul 11, 2014 11:30 PM in response to IdrisSeabright

I See. So that is why I need to be able to transmit my position using cell data. Well then, as long as I don't have a plan that includes the internet, I can probably not use Find My Friends (or Find My IPhone, for that matter).

THanks for clearing this up for me ...

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