Moving a MyTouch 4G Slide handset from T-Mobile on T-Mobile’s network to Solavei on the same network has made a noticeable improvement in call quality and stability. Same handset, same user, same locations and same network. The only change I made was to insert the new SIM, set the WiFi app to cellular preferred and then turn the app off. Solavei doesn't support WiFi calling.
Solavei is a new MVNO using T-Mobile's network. I moved my wife’s T-Mobile line to Solavei yesterday. I entered the port request around 8AM expecting it to take 12 to 24 hours. We planned to do a factory reset before using the new SIM, hoping to fix the call quality issues. The port went live just after noon while we were still out. I went ahead and swapped SIMs. Her calls are loud, clear and consistent since the change.
Why couldn't T-Mobile get better results on their own network?