I recently moved from Windsor, Ontario to Gatineau, Quebec. Now having this problem. Most of the time the network signal level indicator is fluctuating. Sometimes the other end cannot hear me clearly. But I can hear them clearly. And occasionally the call abruptly disconnects.
There's coverage in Gatineau but there could be any # of issues with cell reception. Maybe it's just the particular area you're in? Are you calling from inside or outside? Does it happen to everyone you call or just certain people?