From 3-4 bars, to zero bars, once for 24 hrs+ and once for 12 hours during the day, with TMobile LTE service in the Austin area (*******). No warning either; three calls to customer service yielded no information on why, or when service would be restored. CS does not have access to the field repair activities. The CS members are always nice, friendly, but clueless, kept in the dark by TMobile's bare bones back office infrastructure. Losing customer data, no backups for towers, long down time. It's time to move on.