I eventually changed carriers and phones. Here it got better but cellular connectivity is not a sure thing.
Why this is, is a very long discussion. Ask your carrier why this is but it's rarely the phone. It can be but still the exception.
Recently I purchased Samsung galaxy grand duos .I am facing a strange problem.the data connectivity(internet) became unavailable occasionally .for making data connection available I have to switch off and switch on.is there Any solution fot this problem?
I am using internet from first sim (3g)