iphone 5 connection problem 6.0.2

since i Updated my Iphone5 to IOs 6.0.2. I have a huge number of connectio losts during telephone calls even if i dont move.

I realised it is sometimes, wenn i leave the range of my home WLAN.

Am I the onlyone with this problems?

If someone knows anything against it or can help me, i would be very happy.

Thanks

Jens