How does the HERE navigation app offline?

Discussion in 'iOS Apps' started by sultanoflondon, May 24, 2015.

  1. sultanoflondon macrumors regular

    Joined:
    Dec 3, 2013
    #1
    Hi all,

    I have an iPhone 4S, running iOS 8.3, with the HERE app.

    I don't understand how the app works in terms of how it determines my location offline? For example, if I were to route from London, UK, to Birmingham, UK, using my home Wi-Fi connection, then drive the route with data roaming switched OFF, using the HERE app for navigation, then how does the app know where I am, and more importantly, how does the app determine a new route when I detour from the correct one, for example, if I take a wrong turn?

    Thanks!
     
  2. MagicBoy macrumors 68040

    MagicBoy

    Joined:
    May 28, 2006
    Location:
    Manchester, UK
    #2
    The GPS is not tied to data access.

    By offline, they mean you can download the map data to your iOS device rather than using mobile data like Apple/Google Maps do.
     
  3. sultanoflondon thread starter macrumors regular

    Joined:
    Dec 3, 2013
    #3
    Yes, they allow to download country maps to the iPhone.

    So the GPS module of the iPhone is entirely different from data roaming? So does the iPhone connect to satellites?


    Thanks!
     
  4. MagicBoy macrumors 68040

    MagicBoy

    Joined:
    May 28, 2006
    Location:
    Manchester, UK
    #4
    Yes, the GPS is a separate module. It doesn't "connect" to satellites, it passively receives signals from the satellites it can see and uses them to triangulate it's position using maths. Getting a cold fix can take a few minutes if the location has changed significantly.

    Most SmartPhones can use aGPS to speed up the initial approximate fix using mobile data/WiFi, but will fall back to standard GPS when no network connection is available.

    Suggest you have a read up on GPS. I was using it 10+ years ago with a bluetooth connected GPS receiver and a PocketPC which had no internet connection whatsoever.
     

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