I made an application that displays the currently logged in cell id and lac and some more data. The display is updated about once a second. This works great using the CTelephony API. (In GSM and UMTS networks.) The GSM cell ids are in the range from 10000 to 99999 and the UMTS cell ids are in the range from 100000 to 999999 on my network provider.
It still works if I open a network connection using GPRS over GSM. However if the cell phone is connected to an UMTS network and my application (or another application) is transferring some data in background, the API delivers always a cell id of 0 and a lac of 0. Here is what I get:
Active GPRS connection (GSM) / no data transfered: get valid cell id
Active GPRS connection (GSM) / data transfered : get valid cell id
Active UMTS connection / no data transfered: get valid cell id
Active UMTS connection / data transfered: get an empty cell id (0)!
Is this a known problem? Does anybody made the same experiences? Is there a workaround for this? If needed I can provide the part of my source where the cell id is read.
I'm using a Nokia N80 (V4.0632.0.38) to do the tests.
Thanks for any hints