Resolved Location services without using GPS?

iMacBooked

macrumors 6502a
Original poster
Hello MR, I found alot of topics already about location services, but I can't seem to find an answer to this easy question.
I have a weather app on my iPhone 4S (iOS 7.1.1) to notify me accurately when it's going to rain. In the app description it says that Location Services needs to be enabled of course, but it also says that "there will be a LS symbol all the time in the status bar, but this is NOT a GPS indicator, just a privacy symbol that only indicates our app is checking for your location from time to time. This app never uses the GPS to track your location."
So my question is wether this is possible? I have a LS symbol in my status bar whole the time, is it really not using GPS? I'm worried for this because I don't want the GPS to be on all the time for battery reasons.
 
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cynics

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Jan 8, 2012
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Your location can be figured out from cell tower and wifi networks. If that's what you mean.
 

scaredpoet

macrumors 604
Apr 6, 2007
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So my question is wether this is possible? I have a LS symbol in my status bar whole the time, is it really not using GPS? I'm worried for this because I don't want the GPS to be on all the time for battery reasons.
Location Services is an all or nothing situation when it comes to GPS. If location services is on, GPS is on. No way around that.

That said, that link does detail some ways a developer can get location information without taking up a whole lot of battery life, if they only want to track "significant changes" in a location, rather than get something precise all the time.


The only other way I can think of for a developer to get a location without GPS/Location Services, would be to have the phone "ping" a server that the developer has control of, and then do an IP Geolocation search using your phone's IP address. These aren't too accurate though, particularly on cellular networks.

The only way to know for sure though, is for the developer to give some more detail on how s/he's managing to do this location-without-GPS trick.


One last thing: the more I read the description you posted, the more I'm thinking that maybe too much is being read into the wording here. "This app never uses the GPS to track your location" might just be a really badly worded statement meaning something like "we're not keeping tabs on you or retaining your GPS records, NSA-style." So, LS and the GPS would be used by the app to get your location and pull up a weather forecast, but that information isn't stored anywhere long term for the developer to snoop around with... so, there's use, but no "tracking."
 
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Jaguarr40

macrumors regular
Jul 10, 2014
131
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Sarasota, Florida
Hello MR, I found alot of topics already about location services, but I can't seem to find an answer to this easy question.
I have a weather app on my iPhone 4S (iOS 7.1.1) to notify me accurately when it's going to rain. In the app description it says that Location Services needs to be enabled of course, but it also says that "there will be a LS symbol all the time in the status bar, but this is NOT a GPS indicator, just a privacy symbol that only indicates our app is checking for your location from time to time. This app never uses the GPS to track your location."
So my question is wether this is possible? I have a LS symbol in my status bar whole the time, is it really not using GPS? I'm worried for this because I don't want the GPS to be on all the time for battery reasons.
I7Guy and scaredpoet are correct, It is all or nothing and when you have LS on GPS is on and you should have a colored like point or what looks like a pointer in your status bar. If you look at all of your apps it will explain in the LS settings what color means what. Once again - All or nothing.
 

kdarling

macrumors P6
I7Guy and scaredpoet are correct, It is all or nothing and when you have LS on GPS is on and you should have a colored like point or what looks like a pointer in your status bar. If you look at all of your apps it will explain in the LS settings what color means what. Once again - All or nothing.
Sorry, but I think all of you are incorrect :)

An app can use the very low power Significant-Change location service, which only watches for a change in used/visible cell towers, something the phone is already doing. It does not use GPS or WiFi at all.

For that matter, GPS is not required for other location uses, unless your app asks for accuracy that is only available via GPS. Otherwise it can use WiFi hotspot and/or cell id locating.

.
 
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I7guy

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Nov 30, 2013
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Sorry, but I think all of you are incorrect :)

An app can use the very low power Significant-Change location service, which only watches for a change in used/visible cell towers, something the phone is already doing. It does not use GPS or WiFi at all.

For that matter, GPS is not required for other location uses, unless your app asks for accuracy that is only available via GPS. Otherwise it can use WiFi hotspot and/or cell id locating.

.
I don't think that is what is being said.:cool:

I understand the iphone has gps and a-gps. a-gps using cell tower triangulation, and in addition the iphone can use crowdsourced wifi.

However, an app can use whatever method it chooses, but the iphone user cannot disable GPS services separately from a-gps services, like on a blackberry.
 

Jaguarr40

macrumors regular
Jul 10, 2014
131
2
Sarasota, Florida
I don't think that is what is being said.:cool:

I understand the iphone has gps and a-gps. a-gps using cell tower triangulation, and in addition the iphone can use crowdsourced wifi.

However, an app can use whatever method it chooses, but the iphone user cannot disable GPS services separately from a-gps services, like on a blackberry.
Sorry, but I think all of you are incorrect

An app can use the very low power Significant-Change location service, which only watches for a change in used/visible cell towers, something the phone is already doing. It does not use GPS or WiFi at all.

For that matter, GPS is not required for other location uses, unless your app asks for accuracy that is only available via GPS. Otherwise it can use WiFi hotspot and/or cell id locating.
I agree with I7GUY 100% and what you mentioned about all of us being wrong, Just because an app like a weather app that relies on your location for proper info, If you don't turn on LS/ GPS then all you are going to get is the location you type in where you live in that city for instance but not your area - Same as Google Earth showing you exactly where you live and it takes at least 3 satellites to triangulate to show this info to you.
 
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kdarling

macrumors P6
I don't think that is what is being said.:cool:

I understand the iphone has gps and a-gps. a-gps using cell tower triangulation, and in addition the iphone can use crowdsourced wifi.
A-GPS is not cell tower triangulation. That is a common misconception that came from a mistake that Jobs made once in a speech. A-GPS is GPS with quicker startup satellite info obtained from an Assistance server (re)hosted at Apple.

However, an app can use whatever method it chooses, but the iphone user cannot disable GPS services separately from a-gps services, like on a blackberry.
I think, like many people, you're confusing "GPS" as being equivalent in meaning to Location Services in general. "GPS" means only one thing, and that is that GPS is being used.

I agree with I7GUY 100% and what you mentioned about all of us being wrong, Just because an app like a weather app that relies on your location for proper info, If you don't turn on LS/ GPS ...
Again, LS does not have to mean/use GPS. See above. They are not equivalent terms.

You can have LS turned on, but the app not using GPS.

... In the app description it says that Location Services needs to be enabled of course, but it also says that "there will be a LS symbol all the time in the status bar, but this is NOT a GPS indicator, just a privacy symbol that only indicates our app is checking for your location from time to time. This app never uses the GPS to track your location."

So my question is whether this is possible? I have a LS symbol in my status bar whole the time, is it really not using GPS? I'm worried for this because I don't want the GPS to be on all the time for battery reasons.
Yes, it's quite possible for a weather app to check your (very rough) location without having to use power hungry GPS. See my original response in this thread.
 

I7guy

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A-GPS is not cell tower triangulation. That is a common misconception that came from a mistake that Jobs made once in a speech. A-GPS is GPS with quicker startup satellite info obtained from an Assistance server (re)hosted at Apple.



I think, like many people, you're confusing "GPS" as being equivalent in meaning to Location Services in general. "GPS" means only one thing, and that is that GPS is being used.



Again, LS does not have to mean/use GPS. See above. They are not equivalent terms.

You can have LS turned on, but the app not using GPS.



Yes, it's quite possible for a weather app to check your (very rough) location without having to use power hungry GPS. See my original response in this thread.
a-GPS requires an internet connection to broadcase the cell phone towers information back to the telcos servers without requiring the use of satellites and using much less power. if I recall a-gps can use cell tower triangulation as well.

I wasn't confusing gps with a-gps. GPS requires at least 3 satellites. assisted-GPS requires a network connection. I was merely sayinjg on a blackberry those functions are independently controlled. On an iphone from a user perspecive they are either on completely or off completely.
 

kdarling

macrumors P6
a-GPS requires an internet connection to broadcase the cell phone towers information back to the telcos servers without requiring the use of satellites and using much less power. if I recall a-gps can use cell tower triangulation as well.

I wasn't confusing gps with a-gps. GPS requires at least 3 satellites. assisted-GPS requires a network connection.
Both A-GPS and GPS on the iPhone ALWAYS use GPS satellites to determine their exact location. There is no GPS mode that does not use GPS satellites.

In the case of the iPhone, A-GPS uses a network connection to contact the assistance server, which gives the phone up-to-date satellite status and orbit information via high speed connection, instead of the phone having to download that info itself from the satellites at 50 bits per second.

There are other forms of A-GPS, such as found on Verizon dumb phones, who transfer the raw GPS info they receive, to Verizon servers to do the calculations and take into account local signal variations, but they do not apply here.

I was merely sayinjg on a blackberry those functions are independently controlled. On an iphone from a user perspecive they are either on completely or off completely.
Right, on other mobile devices the user can often separately turn off the use of GPS.

What we're saying here, and what is the answer to the original question, is that an APP can also choose NOT to use (or require) GPS if it doesn't need super accuracy.
 

iMacBooked

macrumors 6502a
Original poster
Wow, thank you all for these answers! :)
There still seems to be a lot of misconception about LS, so I'm glad I asked this question on MacRumors.

The more I read the description you posted, the more I'm thinking that maybe too much is being read into the wording here. "This app never uses the GPS to track your location" might just be a really badly worded statement meaning something like "we're not keeping tabs on you or retaining your GPS records, NSA-style." So, LS and the GPS would be used by the app to get your location and pull up a weather forecast, but that information isn't stored anywhere long term for the developer to snoop around with... so, there's use, but no "tracking."
No, this developer really especially meant that the app would never use power hungry GPS, but would use other ways to track our location. I just tried to translate their description (the app is in my Dutch language).

Sorry, but I think all of you are incorrect :)

An app can use the very low power Significant-Change location service, which only watches for a change in used/visible cell towers, something the phone is already doing. It does not use GPS or WiFi at all.

For that matter, GPS is not required for other location uses, unless your app asks for accuracy that is only available via GPS. Otherwise it can use WiFi hotspot and/or cell id locating.
Yes, it's quite possible for a weather app to check your (very rough) location without having to use power hungry GPS. See my original response in this thread.
Hmm, I see your point. But there is a Location Services symbol in my statusbar, non-stop. So that could just mean the app is using only WiFi/cell id locating? It's just weird that the symbol is there all the time, this is why I think it could still be using GPS instead. Because if it would really use WiFi/cell id locating, then why would the symbol appear the whole day, and not only the moment the app checks for your location?
 

kdarling

macrumors P6
Hmm, I see your point. But there is a Location Services symbol in my statusbar, non-stop. So that could just mean the app is using only WiFi/cell id locating?
Yes, but as I said, I seriously doubt that the app is using any active locating. It's almost certainly using the passive check for a "significant change" (see below).

Note: there are multiple location symbols. A grey one simply means that LS has been used in the past day.

It's just weird that the symbol is there all the time, this is why I think it could still be using GPS instead. Because if it would really use WiFi/cell id locating, then why would the symbol appear the whole day, and not only the moment the app checks for your location?
Probably because the app isn't doing the checking, the OS is. It's been asked to watch all the time, and wake up the app when a gross location change has occurred, which can be triggered by switching between cells.

For a weather app, that's all the accuracy that's needed. No need for GPS, or WiFi, or Bluetooth iBeacons.

The great thing about this method is how low power it is. The phone's baseband code is already constantly checking for towers, so there's almost no extra overhead until the app needs to be notified.
 

I7guy

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Nov 30, 2013
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Both A-GPS and GPS on the iPhone ALWAYS use GPS satellites to determine their exact location. There is no GPS mode that does not use GPS satellites.

In the case of the iPhone, A-GPS uses a network connection to contact the assistance server, which gives the phone up-to-date satellite status and orbit information via high speed connection, instead of the phone having to download that info itself from the satellites at 50 bits per second.

There are other forms of A-GPS, such as found on Verizon dumb phones, who transfer the raw GPS info they receive, to Verizon servers to do the calculations and take into account local signal variations, but they do not apply here.



Right, on other mobile devices the user can often separately turn off the use of GPS.

What we're saying here, and what is the answer to the original question, is that an APP can also choose NOT to use (or require) GPS if it doesn't need super accuracy.
You are correct assisted gps needs a gps even for an approximate location, but it does not need the phones GPS, which I didn't state clearly.

Using a server side a-gps solution obviously requires GPS, just doesn't require the phone to waste CPU and power on acquiring a satellite lock for what is an approximate location.
 

kdarling

macrumors P6
You are correct assisted gps needs a gps even for an approximate location, but it does not need the phones GPS, which I didn't state clearly.
No sir, this is still not right. I suspect you've been innocently misled by all those inaccurate articles that arose after Jobs made a mistake describing A-GPS in the iPhone 3G.

Again, both GPS and A-GPS use the GPS receiver on the phone. Always. There are no exceptions.

Any method that does not use the GPS on the phone, is not GPS. It's some other locating method. (There are also hybrid locating methods, which use more than one kind of system.)

Using a server side a-gps solution obviously requires GPS, just doesn't require the phone to waste CPU and power on acquiring a satellite lock for what is an approximate location.
A server side A-GPS solution, such as Verizon uses on their dumbphones, still requires the phone to receive GPS data.

The only difference is that most dumbphones don't have the CPU power to do the location calculations, so the data is uploaded to the carrier to do that. It's also uploaded for E911 locating purposes.

None of this section applies to the iPhone, however.
 

I7guy

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No sir, this is still not right. I suspect you've been innocently misled by all those inaccurate articles that arose after Jobs made a mistake describing A-GPS in the iPhone 3G.

Again, both GPS and A-GPS use the GPS receiver on the phone. Always. There are no exceptions.

Any method that does not use the GPS on the phone, is not GPS. It's some other locating method. (There are also hybrid locating methods, which use more than one kind of system.)



A server side A-GPS solution, such as Verizon uses on their dumbphones, still requires the phone to receive GPS data.

The only difference is that most dumbphones don't have the CPU power to do the location calculations, so the data is uploaded to the carrier to do that. It's also uploaded for E911 locating purposes.

None of this section applies to the iPhone, however.
But it doesn't need the satellite data, for approximate locations. Even though technically the gps chip is used.
 

kdarling

macrumors P6
But it doesn't need the satellite data, for approximate locations. Even though technically the gps chip is used.
True, for approximate locations, there's no need for satellite data . Cell id or WiFi hotspot locating can be used.

However, if it's not using satellite data, it's not GPS. If it's not GPS, the GPS chip would not be used.

Hmm. What are you thinking a "GPS chip" does? Perhaps that's the disconnect. It's not a locating processor if that's what you think. The actual processing is done by the main CPU.
 

I7guy

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True, for approximate locations, there's no need for satellite data . Cell id or WiFi hotspot locating can be used.

However, if it's not using satellite data, it's not GPS. If it's not GPS, the GPS chip would not be used.

Hmm. What are you thinking a "GPS chip" does? Perhaps that's the disconnect. It's not a locating processor if that's what you think. The actual processing is done by the main CPU.
That is what a-GPS is supposed to do, if the phone can't acquire the satellites. An approximate location. No? Or does agps work differently on the iPhone than my blackberry?
 

kdarling

macrumors P6
That is what a-GPS is supposed to do, if the phone can't acquire the satellites. An approximate location. No? Or does agps work differently on the iPhone than my blackberry?
Aha. I looked around on some BB forums (I used to program BBs for work) and noticed a lot of confusion there as well.

The most common misconception I see, is the notion that "A-GPS" means the device uses cell towers if it can't find a GPS signal. That's incorrect. A-GPS/GPS is GPS only.

If the device can't find the GPS signal, then the OS will instead switch to alternative methods such as cell id or hotspot or iBeacon. However, those alternative methods are not A-GPS.

I hope that helps.

--

OP, none of this applies to your question. GPS is not involved for that weather app.
 

I7guy

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Aha. I looked around on some BB forums (I used to program BBs for work) and noticed a lot of confusion there as well.

The most common misconception I see, is the notion that "A-GPS" means the device uses cell towers if it can't find a GPS signal. That's incorrect. A-GPS/GPS is GPS only.

If the device can't find the GPS signal, then the OS will instead switch to alternative methods such as cell id or hotspot or iBeacon. However, those alternative methods are not A-GPS.

I hope that helps.

--

OP, none of this applies to your question. GPS is not involved for that weather app.
None if what you are posting makes any sense to me as I remember blackberry maps locks in immediately with an approximate location while it locks onto the satellites. And not only does blackberry maps tell you how many satellites but what mode it is in.

So my interpretation is that a-gps uses cell towers and internet to determine an approximate location, without the phone having to lock onto satellites.
 

kdarling

macrumors P6
None if what you are posting makes any sense to me as I remember blackberry maps locks in immediately with an approximate location while it locks onto the satellites. And not only does blackberry maps tell you how many satellites but what mode it is in.

So my interpretation is that a-gps uses cell towers and internet to determine an approximate location, without the phone having to lock onto satellites.
Thank you! Now it's clear. You were conflating all the methods under one name.

What's happening (and this is common to most modern smartphones) is that the device is using a sequence of DIFFERENT methods, starting with the fastest (and less accurate), and ending up with the slowest to lock (and most accurate).

So, first it uses cell id, then WiFi, then finally A-GPS (if GPS is enabled).

The GPS method can use starting location hints from the first two methods to help it speed up a lock, but they are still totally different methods.

Regards.
 
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takeshi74

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Feb 9, 2011
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So my question is wether this is possible?
Absolutely. I have an app that I rely on that uses Location Services but not GPS. It would be very obvious from comparing battery life before and after if it was constantly using my GPS receiver to determine my location.

An app can use the very low power Significant-Change location service, which only watches for a change in used/visible cell towers, something the phone is already doing. It does not use GPS or WiFi at all.
See also:
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html

So my interpretation is that a-gps uses cell towers and internet to determine an approximate location, without the phone having to lock onto satellites.
And that interpretation is incorrect. aGPS is GPS. As stated above, all GPS uses the GPS satellites to determine location. As stated above, the only difference between GPS and aGPS is that ephemeris data is downloaded from an assistance server for a faster initial fix with the latter.

Tower triangulation has nothing to do with GPS or aGPS. Towers are only used by aGPS to obtain the ephemeris data. The ephemeris data reveals nothing about the receiver's location. It's used to locate the satellites. Non aGPS receivers have to download this information from the satellites and because of the bandwidth it takes a very long time. Interruptions can also increase the time to first fix as the download has to start over. aGPS cuts down on the time to first fix by using faster download methods.

There are plenty of reputable resources you can read on the matter instead of relying on speculation and forum posts.
 
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BruiserB

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An iPod touch can use location services and it has no GPS. There are databases of wifi MAC addresses along with the location of the wifi router. I think this is some of the data that Google collects as they drive their streetview cars around. An iPod touch can often come up with a pretty close location just based on what wifi signals it "sees". This is also for iPhones to get an estimate for assisted GPS.

The OP was questioning if his weather app is using GPS. I'm guessing yes. What the explanation said is that they aren't tracking you by GPS. I think this just means they aren't keeping a history of where your phone is connecting to GPS as a privacy consideration. They know where you are when the app updates but can't tell someone the history of where you've been. At least that's how I read it.
 

I7guy

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Absolutely. I have an app that I rely on that uses Location Services but not GPS. It would be very obvious from comparing battery life before and after if it was constantly using my GPS receiver to determine my location.


See also:
https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html


And that interpretation is incorrect. aGPS is GPS. As stated above, all GPS uses the GPS satellites to determine location. As stated above, the only difference between GPS and aGPS is that ephemeris data is downloaded from an assistance server for a faster initial fix with the latter.

Tower triangulation has nothing to do with GPS or aGPS. Towers are only used by aGPS to obtain the ephemeris data. The ephemeris data reveals nothing about the receiver's location. It's used to locate the satellites. Non aGPS receivers have to download this information from the satellites and because of the bandwidth it takes a very long time. Interruptions can also increase the time to first fix as the download has to start over. aGPS cuts down on the time to first fix by using faster download methods.

There are plenty of reputable resources you can read on the matter instead of relying on speculation and forum posts.
Already stated that gps info does not come from the phone with a-gps. Yes the GPS info does come from somewhere...in the case of a-gps the internet delivers the appropriate gps info from back-end servers.
 

maflynn

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As mentioned wifi, LTE and GPS are all options for the phone to determine your location. I don't which one it relies mostly on though.