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MelSnyder

macrumors newbie
Original poster
Oct 23, 2011
2
0
When I say "true GPS" I mean the ability to function independently of a data service in conjunction with a mapping program like Google maps?

Driving from Porto to Lisbon airport, I was running a bit late, and ran past the precise ending hour for my data package with the SIM chip in my Vodaphone hotspot.

When the data plan expired, my iPad and iPhone 6 Plus went blind.

I figured that if the iPhone 6 Plus had true GPS, it could pick up satellites without a data plan - and that a true GPS integrated with Google maps would have continued to show my position on the main highway, but it didn't - and it sure didn't on my iPad 3 running iOS 8 (at the time). It seemed that any GPS function on either device was still linked to a data plan.

I now have an iPhone 7 Plus (bought unlocked for cash from my local Apple store, now with a Verizon SIM in it). I am leaving in 2 weeks for Greece and Norway - the case of Norway, I will be up in the thinly populated fjords north of Bergen, and in Greece, the less thinly populated regions of the Peloponnesus. I plan to purchase SIM chips for my iPhone 7 Plus and my hot spot because it's easier for my partner to navigate for me on my iPad Pro 9.7.

My question: Do I really need SIM chips for navigation, or just for data/phone comms?
 

maxjohnson2

macrumors 6502
Mar 24, 2017
351
238
It works even on Airplane mode, but without data your map app stopped downloading new areas.

Google Maps now have offline mode. Nokia Here (Microsoft) is a good alternative.
 
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Phil A.

Moderator emeritus
Apr 2, 2006
5,800
3,100
Shropshire, UK
As others have said, your issue wasn't with GPS, but rather with Google Maps needing a data connection to download the maps. If you use an offline capable navigation app (I've not tried Google Maps offline but do use Copilot), you don't need a data connection at all
 
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BrettApple

macrumors 65816
Apr 3, 2010
1,145
488
Heart of the midwest
Yes and it does so as far back as the iPhone 3GS at least.

I actually still actively use a 3GS running iOS 6 with Maps.Me where I have downloaded multiple states maps locally to use in no signal zones such as in the mountains of Colorado. It has fairly detailed maps with even small trails showing up and it lets me put little waypoints along the way in case I get lost. Routing works too, completely offline.

Same goes for newer iPhones.

Here's an example screenshot. While this was with my SIM out of it and on WiFi at the time it works completely offline in the middle of nowhere as long as there's a view of the sky.

DBNCWMk.png
 

zorinlynx

macrumors G3
May 31, 2007
8,347
18,558
Florida, USA
It does indeed have true GPS. In fact, in a semi-recent iOS release Apple finally fixed it so that GPS will work even in airplane mode.

It's odd that Google Maps just stopped working, because it will typically download all the data it needs for your current trip at the start so guidance will work even if there is no data.

My suspicion is maybe you deviated from the original route (either intentionally or accidentally) and it was then unable to contact the server to get a new route, so it went dead. It's a good idea to always download maps for areas you will be in if you expect you might lose data coverage.
 

Stefan johansson

macrumors 65816
Apr 13, 2017
1,294
607
Sweden
When I say "true GPS" I mean the ability to function independently of a data service in conjunction with a mapping program like Google maps?

Driving from Porto to Lisbon airport, I was running a bit late, and ran past the precise ending hour for my data package with the SIM chip in my Vodaphone hotspot.

When the data plan expired, my iPad and iPhone 6 Plus went blind.

I figured that if the iPhone 6 Plus had true GPS, it could pick up satellites without a data plan - and that a true GPS integrated with Google maps would have continued to show my position on the main highway, but it didn't - and it sure didn't on my iPad 3 running iOS 8 (at the time). It seemed that any GPS function on either device was still linked to a data plan.

I now have an iPhone 7 Plus (bought unlocked for cash from my local Apple store, now with a Verizon SIM in it). I am leaving in 2 weeks for Greece and Norway - the case of Norway, I will be up in the thinly populated fjords north of Bergen, and in Greece, the less thinly populated regions of the Peloponnesus. I plan to purchase SIM chips for my iPhone 7 Plus and my hot spot because it's easier for my partner to navigate for me on my iPad Pro 9.7.

My question: Do I really need SIM chips for navigation, or just for data/phone comms?
All phones use A-GPS,which means that it connects to maximum 3 satellites,and get support from cellphone networks. A dedicated GPS receiver can connect to up to 12 satellites. In the phone,you also need either wifi connection or cellphone network to download maps.
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
Yes it's a real gps.
And if you're using an app that pulls map info via carrier data while using it then you ran out of data then that's on you.
If you use an app that has the maps stored on the device you can navigate with no wireless data needed at all.
 

zorinlynx

macrumors G3
May 31, 2007
8,347
18,558
Florida, USA
All phones use A-GPS,which means that it connects to maximum 3 satellites,and get support from cellphone networks. A dedicated GPS receiver can connect to up to 12 satellites. In the phone,you also need either wifi connection or cellphone network to download maps.

You have to lock onto at least 3 satellites to get a fix, but an A-GPS receiver can lock onto more satellites just fine. There's nothing in the iPhone GPS chipset that will keep it from doing so.

An iPhone can still get a GPS fix without downloading data; it'll take a long time just like with a dedicated GPS unit, but it'll work just fine. Also, I wouldn't be surprised if the GPS chipset connects to as few satellites as necessary to reduce power consumption; that would only be sensible on a portable battery-powered device.
 

Mrbobb

macrumors 603
Aug 27, 2012
5,009
209
Phil A. is right on the money. U looking at the wrong culprit. Is the mapping app that needs constant data. Look for an app that can work offline.
 
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bopajuice

Suspended
Mar 22, 2016
1,571
4,348
Dark side of the moon
I purchased the TomTom GPS App for my iPhone years ago. I like it because all the maps are preloaded. No service or signal needed to use. I would assume the phone would have to use true GPS for the App to work no?

Also my Drone needs to have a phone or tablet with GPS in order to function. I believe it uses wifi.
 
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HEK

macrumors 68040
Sep 24, 2013
3,547
6,080
US Eastern time zone
I download Maps.me it's great, has regular map updates. I have entire North America on phone so don't need data or LTE for mapping. GPS works independently showing me on those downloaded maps. With three satilites GPS gives lat/long position, with four or more satelights accuracy improves and elevation is available. When you download the maps be sure you are on wifi as it's a lot of data.
 
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Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
I use Navigon.
You dont need to use any carrier data.
You download the maps you need. Lets say certain US states you plan to visit or certain countries maps and you're good.
Dont have to worry about reliable cellular signal while driving around in various locations too.
Good GPS app for sure.
 

Stefan johansson

macrumors 65816
Apr 13, 2017
1,294
607
Sweden
You have to lock onto at least 3 satellites to get a fix, but an A-GPS receiver can lock onto more satellites just fine. There's nothing in the iPhone GPS chipset that will keep it from doing so.

An iPhone can still get a GPS fix without downloading data; it'll take a long time just like with a dedicated GPS unit, but it'll work just fine. Also, I wouldn't be surprised if the GPS chipset connects to as few satellites as necessary to reduce power consumption; that would only be sensible on a portable battery-powered device.
Dude,I compared the GPS accuracy from my phone with a lowrance marine GPS/chart plotter,the iPhone 6 had about 12 meters accuracy,while the (more expensive) lowrance gear had approx 1,5 meters,for street use,this might not be important,but for me,navigating in shallow,rocky waters,where a meter or so wrong would mean disaster and possible death,I would not trust the phone that much.
 

zorinlynx

macrumors G3
May 31, 2007
8,347
18,558
Florida, USA
Dude,I compared the GPS accuracy from my phone with a lowrance marine GPS/chart plotter,the iPhone 6 had about 12 meters accuracy,while the (more expensive) lowrance gear had approx 1,5 meters,for street use,this might not be important,but for me,navigating in shallow,rocky waters,where a meter or so wrong would mean disaster and possible death,I would not trust the phone that much.

12 meters doesn't sound right. Are you sure you weren't reading it in feet? That's about the accuracy my iPhone gets with a clear sky.
 
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Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
Dude,I compared the GPS accuracy from my phone with a lowrance marine GPS/chart plotter,the iPhone 6 had about 12 meters accuracy,while the (more expensive) lowrance gear had approx 1,5 meters,for street use,this might not be important,but for me,navigating in shallow,rocky waters,where a meter or so wrong would mean disaster and possible death,I would not trust the phone that much.

Shallow rocky waters?
The iphone GPS is mostly to navigate while driving and general use. And its not off by 12 meters, its pretty accurate to multiple lane use on the highway. But If you want something even more accurate that will not cause possible death to whatever you need it for then get something specific for your use.
The iphone GPS is more than accurate enough for everyone.
 

HEK

macrumors 68040
Sep 24, 2013
3,547
6,080
US Eastern time zone
Dude,I compared the GPS accuracy from my phone with a lowrance marine GPS/chart plotter,the iPhone 6 had about 12 meters accuracy,while the (more expensive) lowrance gear had approx 1,5 meters,for street use,this might not be important,but for me,navigating in shallow,rocky waters,where a meter or so wrong would mean disaster and possible death,I would not trust the phone that much.
Anyone using iPhone to navigate waterways or navigate aircraft is nuts.
 
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Stefan johansson

macrumors 65816
Apr 13, 2017
1,294
607
Sweden
12 meters doesn't sound right. Are you sure you weren't reading it in feet? That's about the accuracy my iPhone gets with a clear sky.
As I live in Europe,I never had phone units set to feet. And yes,in north Europe,the American GPS system used in cellphones is not too accurate.
[doublepost=1492448777][/doublepost]
Anyone using iPhone to navigate waterways or navigate aircraft is nuts.
Exactly why I use my lowrance plotter.
[doublepost=1492449053][/doublepost]
Shallow rocky waters?
The iphone GPS is mostly to navigate while driving and general use. And its not off by 12 meters, its pretty accurate to multiple lane use on the highway. But If you want something even more accurate that will not cause possible death to whatever you need it for then get something specific for your use.
The iphone GPS is more than accurate enough for everyone.
The accuracy when on roads is one thing,out in roadless country or at sea,the phone has no roadmap to assist it with accuracy,so an iPhone might be good as vehicle navigator,but when you really need accuracy,it's almost useless. When I need a GPS,is mostly when there is no roads or power lines to follow,or when I go fishing. The GPS is useful for taking my boat home in dark,foggy nights.
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
As I live in Europe,I never had phone units set to feet. And yes,in north Europe,the American GPS system used in cellphones is not too accurate.
[doublepost=1492448777][/doublepost]
Exactly why I use my lowrance plotter.
[doublepost=1492449053][/doublepost]
The accuracy when on roads is one thing,out in roadless country or at sea,the phone has no roadmap to assist it with accuracy,so an iPhone might be good as vehicle navigator,but when you really need accuracy,it's almost useless. When I need a GPS,is mostly when there is no roads or power lines to follow,or when I go fishing. The GPS is useful for taking my boat home in dark,foggy nights.

I can see where you're coming from.
Yes, if there's no map info available on the app or out in the woods made up of dirt roads or water ways its pretty much pointless.
Never had the need to use my cellphones GPS in those condition but something better and more specific to your needs would work.
 

Stefan johansson

macrumors 65816
Apr 13, 2017
1,294
607
Sweden
I can see where you're coming from.
Yes, if there's no map info available on the app or out in the woods made up of dirt roads or water ways its pretty much pointless.
Never had the need to use my cellphones GPS in those condition but something better and more specific to your needs would work.
Exactly,that's why I use better gear,unless I'm in some big city.
 
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