User Profile

Is Reachability reliable to make a check if I have cellular connection to make a call. I just need to check the availability of cellular signal and notify the user that he is receiving cellular signal and can make a call . This for non wi-fi areas and with sparse cellular connectivity to notify a user that they have a cellular connection to make a call.To be more specific if I get a reply from Reachability that cellular connectivity is available, is it possible that the user still can't make a call or other way that Reachability can not identify cellular connectivity is available and yet user can make a call.