GPS - assistance data

[Mumbles]

Hi everyone, I've been having a problem with my Xperia Z when using the GPS receiver. Some times it worked, and other times it couldn't find a signal even after a whole hour. I searched Google and found the solution on this forum in this thread, "purge assistance data".

However I was wondering if it's possible to purge this assistance data automatically. I have a GPS tracking app on my phone in case I lose it. However, I can't tell my phone to purge the assistance data if I've lost it or left it at work etc. I know the assistance data allows the phone to determine its location much quicker, but I don't mind waiting longer (a full minute if that's what it takes) if it means the receiver works every time... So far when the phone has only just been turned on, the longest time it's taken to determine the location is only 10 seconds

[Rickard]

I don't know of any way to automatically purge the assistance data but if you want to disable the assisted start i believe it should be enough to remove the APN-type ",supl" from all APNs under Settings -> More -> Mobile networks -> Acces Point Names. Check all APNs you have here and remove ",supl" from the field APN-type in all of them.

[Mumbles]

Hi, sorry for not noticing this earlier. I only have one APN ("T-Mobile UK" general.t-mobile.uk) and the APN-type is "Not set". Should I be setting this to something? I have no idea what would be valid and what would be invalid...

[Rickard]

I don't think you're using assisted start then. I believe you need to have APN-type "supl" for this to work.

I would recommend that you set the APN-type in this account to "default". If you also have MMS-settings in it (MMS-proxy, port and so on), set APN-type to "default,mms".

Regarding GPS stops working, does it really solve the problem when you purge the assistance data?

Have you tried updating your phone?

[Mumbles]

Hi, yes purging the assistance data does seem to fix this issue every time the GPS stops working. I believe the phone is not updated. I'm in the UK and my Carrier is Virgin Mobile. Virgin have not yet released the update to 4.2.2 Jelly bean, and the build number is 10.1.A.1.434 which I believe is very old... It's so old that the infamous lockscreen bypass bug is still present on my phone. I've reported this to them, but they gave the usual "we need to test it first" stock response.

My phone refuses to update to 4.2.2 OTA, and also refuses with PC Companion.

I've just updated the APN-type field to "default,mms" to see if it improves things. Thanks for the advice on what to type into that because since it wasn't a drop down box, I had no idea what to write...