Do you need a simcard

[bbtony]

I was under the impression that you do not need a SIM card to run Maprun6. However at a recent event I was unable to locate at the start until I took a sim card from another phone. As soon as I put the sim card in I got an instant location connection.
Can some one please enlighten me?

[MichaelRaz]

You didn't mention what type/model of phone you are using.  Tested with my iPhone XS Max: Removed sim card and restarted (turned off WiFi) and checked both a GPS diagnostic app and MapRun6:  Both found satellites and got location fixes. Didn't try it in airplane mode without a sim card but, given your description, not likely the mode you were in.
Only thing I can suggest is that, without a sim card, the GPS lock might take a lot longer as Assisted GPS is not available.
One thing that I have not figured out is how the "supplemental" GPS impacts an iPhone, if at all.  I had suspected that without a sim card and no wifi, going to Supplemental Only lose GPS but I didn't see any difference between GPS, GPS & Supplemental, and Supplemental only.

[terribletim]

Hi to expand on BBTony's question , He was using Android but I had the same problem with my iPhone as did a number of others mainly using Android. The start was located in an area of very poor phone signal, so poor one competitor couldn't even send a text. I assumed my iPhone was user error on my part but later in the day I opened Maprun6 and it got a GPX fix very quickly, it is almost as if the phone signal issue was preventing the GPX fix as my phone found its location on Viewranger no problem. But this wouldn't account for BBTony's issue with his SIMless phone. I couldn't try my SIMless phone as I had forgotten to download the course in advance.

[Peter Effeney]

In summary:
- MapRun does not need a SIM. Some clubs have a set of loan phones which do not have SIMs
- Make sure you are using the latest version: MapRun6
- Because phones use A-GPS (Assisted-GPS), as Michael says, it could take a lot longer to get an initial fix if the phone does not have a cellular or Wifi connection

More details:
- MapRun6 uses two software libraries to ensure compatibility with the widest range of devices.
- Both libraries, take locations from the same underlying source... That is the GPS hardware in the phone provides locations to the Android/iOS operating system which then provides locations to Apps (using locations services).
- Currently the main location library delivers locations when MapRun6 is being displayed on the screen, and when the screen is blanked. The supplementary library does not work when the screen is blanked.

Peter

[MichaelRaz]

(iPhone): One thing I find handy is to install a GPS diagnostic app that allows a check on the GPS location status of the phone.  I use GPS Data and GPS Diagnostic - either allows a more comprehensive status of signal quality etc. in reality, as both these apps and MapRun get the data provided by the phone, between the MapRun bottom status screen and the log, pretty much the same info is available, just easier to view on a single page with the dedicated app - and gives you the ability to confirm that any location issue is not related to MapRun.  
I sometimes use a Bluetooth GPS receiver with the phone (for check sites) and the diagnostic app will confirm to me that the GPS is coming from this not the iPhone native chip.  Although the Bluetooth GPS can do 10hz, the iPhone system will provide a maximum of 4hz to any app (still better that 1hz).  Android (with the right software) can apparently get the full 10hz.