What does it mean when HD is displayed on a mobile phone?

If you are using a vivo mobile phone, the status bar displays the HD logo, which means that the mobile phone card is successfully registered to the high-definition voice call (VoLTE service). HD1 means that card 1 is in the network, and HD2 means that card 2 is in the network. HD12 means that both mobile phone cards have been registered for high-definition voice calls.

VoLTE is a basic communication service that requires data, voice, video and other services to be carried. Once the VoLTE function is turned off, the communication experience will be affected, such as inability to make incoming/outgoing calls. Therefore, please do not turn off the VoLTE function to ensure that your call quality and network experience are not affected.

*Note:

1. Telecom cards cannot register to the 5G NSA network after turning off VoLTE; China Unicom cards can register to the NSA network after turning off VoLTE; cannot register to the 5G SA network after turning off VoLTE . ?

2. After turning off the VoLTE service, the system will prompt you to turn on VoLTE once a day on the dial-up interface. ?

3. The VoLTE function is enabled by default on the mobile phone. There is no corresponding setting option in the mobile phone (from 21 years onwards). You can contact the operator's customer service to cancel the VoLTE service.

The contact numbers of China’s four major operators are: 10099 (China Radio and Television), 10086 (China Mobile), 10010 (China Unicom), and 10000 (China Telecom).

For more usage doubts, you can go to the vivo official website--My--Online Customer Service--Enter manual and consult online customer service for feedback.