What you are seeing may be normal. When the phone first loses signal it tries to reconnect immediately. If it fails it waits a short while (a few seconds), then tries again. The gap between tries keeps getting longer to preserve the battery. It will eventually reach a couple of minutes between tries. Turning to airplane mode for 15 seconds starts the search over.
Here in Sweden it is a big problem that only iphone 5 has, and only with the carrier "3".
3 is the name of a carrier here in Sweden.
All the iphone 5 with the carrier 3 has this problem. I have called apple and the carrier. No solution jet.
I have an original unlocked Iphone 5 with OS 6.0.1.
I have restarted, resetted, reupdated "re" everithing... even used the phone 24 hours completely clean in factory settings.
To make sure it wasn´t the phone that had a problem, I tryed with 2 other simcards from other carrier and they worked perfect. The service is coming back with them. Only with all the simcards from three "3" carrier, the network never comes back.
I tryed to put the "3" simcards on the iphone 4s with OS 6.0.1 and they worked fine, the network was coming back.
It seams to be a problem with the combination of the "3" simcard and the "3"network and iphone 5.
I have been thinkin, what is different with "3" from other carriers???
The difference is that 3 doesn have any gsm, edge, 2g antennas. They only use 3g, umts antennas.
All other carriers uses the gsm 2g edge antennas where 3g umts lte is not available.
This could be the problem.
I am afraid that Iphone 5 searches for edge gsm 2g antennas when the 3g disappears and gets stuck there even when the 3g network comes back.
Could it be that in the software it was forgotten to search for 3g again when the 3g network comes back?
I mean the the software tells the iphone 5 to search for edge on and on, but never tells it to search for 3g again?
I wish an apple technician could read this.
Thanks again everyone, today I spoke with Tmobile my provider and they asked if I had turned off LTE (4g) as this can interupt finding normal signal. Since turning this off I have not had the signal dropout problems.
Settings - General - Mobile Data - Enable LTE - OFF
If anyone has a problem I'd suggest doing this if your not a 4g customer
I'm tacking a similar issue where after a period of time in my work buildings that have notoriously poor to no signal that my phone will be stuck with no service or a loop of no service - edge - no service. i have to toggle airplane mode when i leave the building and a strong 4G (HSPA+) is delivered. where i am in PA/NJ United States AT&T hasn't rolled out LTE. Going to try to keep LTE off and see if that helps.