WIFI Calling Issue

Try turning off Bluetooth. It worked great for me.

 

I absolutely hate the wi-fi calling feature on my mytouch 4g

It's decent when you have no signal but it does not work at all how it was advertised

and the mytouch 4g has such a low wi-fi signal
I am in the room right next to where my router is located
and if i barely touch the left hand corner, it loses reception(mind u i am one room over)

However, if i am in the same room...of course it works perfectly and the wi-fi calling works flawlessly

 

I too have been disappointed with the extremely poor quality of WiFi calling on the Mytouch 4G. I even went so far as to buy a new high-end router and set my phone's wireless connection for the highest priority QOS thinking it might resolve the problem. Bluetooth is a requirement for me and unfortunately the new router didn't make much of a difference in call quality. After two firmware upgrades to the phone in the past year I couldn't believe that the problems discussed here hadn't been resolved.

After doing some investigation online I discovered that severe interference between Bluetooth and 2.4 gig Wifi (802.11g) can be a problem on many devices. It seems the Mytouch 4g is especially prone to such issues.

The solution was switching the phone to the 5 gig Wifi band (802.11a). The MT4G specs don't include this capability in most reviews and product sheets. It also doesn't show up on either the T-Mobile or HTC web page, but the phone works great on that band. For the first time I'm able to use the Wifi calling feature with my Bluetooth headset. Call quality has been just fine.

 

I too have been disappointed with the extremely poor quality of WiFi calling on the Mytouch 4G. I even went so far as to buy a new high-end router and set my phone's wireless connection for the highest priority QOS thinking it might resolve the problem. Bluetooth is a requirement for me and unfortunately the new router didn't make much of a difference in call quality. After two firmware upgrades to the phone in the past year I couldn't believe that the problems discussed here hadn't been resolved.

Apparently something HAS been changed in the latest firmware. Wifi calling now works fine and so does my Bluetooth headset. I've found various articles online that discuss the severe interference that can occur between Bluetooth and 2.4 gig Wifi (802.11g). It seems the Mytouch 4g is especially prone to such issues. The solution for getting the headset to work was switching the phone to the 5 gig Wifi band (802.11a). The MT4G specs don't include this capability anywhere I've found including either the T-Mobile or HTC web page, but the phone works great on that band. For the first time I'm able to use the Wifi calling feature with my Bluetooth headset. Call quality has been just fine.

 

It may be old but much less devices uses the 5.8ghz frequency/bandwidth making it much better than b/g/n/

 

Try NetTalk app, it cannot receive calls, but at least you may learn something. Sounds like your internet is slow. How does it preform on another wifi?