How does oppo Mobile Unicom turn off HD?

If you use an OPPO phone (ColorOS system)

The "VoLTE HD Call" function belongs to the business scope of mobile phone SIM card operators (China Telecom, China Unicom and China Mobile). After the operator activates and successfully registers the "VoLTE HD Call" function, turn on the "VoLTE switch" on the mobile phone, and the "HD" sign will be displayed in the status bar of the mobile phone.

How to close the "HD" sign in the mobile phone status bar;

ColorOS 1 1 and above: the phone turns on the "VoLTE switch" by default, and the "VoLTE switch" entrance is no longer displayed. If you need to cancel the "VoLTE HD Call" function and the mobile phone status bar does not display the "HD" logo, please contact the operator's customer service.

Coloros version 7.0-7.2: enter the phone "Settings >; SIM card and traffic management >: select SIM card > turn off VoLTE HD calling. This operation only turns off the "VoLTE switch" on the mobile phone, and the "HD" sign will not be displayed in the status bar of the mobile phone.

Coloros version 3.2-6. 1: go to phone settings > dual card and mobile network > select a SIM card > turn off VoLTE calling. This operation only turns off the "VoLTE switch" on the mobile phone, and the "HD" sign will not be displayed in the status bar of the mobile phone.

Tips:

①OPPO models use telecom cards to turn on the "VoLTE switch" by default, and mobile phones cannot turn off this switch.

② If the "5G switch" is turned on when the ②OPPO5G model uses Unicom card, the mobile phone will turn on the "VoLTE switch" by default. To turn off the VoLTE switch, turn off the 5G switch first, and then turn off the VoLTE switch.

③③oppo 5g models use the mobile card to turn on the "VoLTE switch" by default, and the mobile phone can turn this switch on/off by itself.

④ VoLTE switch cannot be set during the call.