my iphone 4 has trouble maintaining a connection to my mobile provider, i updated the ios to 6.0.1 and ever since i keep losing mobile network. the only way i can get a connection is by turning of my phone for at least an hour then it gets a connecton

my iphone 4 has trouble maintaining a connection to my mobile provider,

i updated the ios to 6.0.1 and ever since i keep losing my mobile network connection.

the only way i can get a signal is by turning my phone off for an hour and then switching it on.

this gives me a mobile signal but after a while i lose it and all i get is no service or searching.

i have reset my phone and had a new sim card sent out but none of these solutions solved my problem.

any help please?