op why there is no Volty call function button on it

Hello. To use the VOLTE function, you need to contact the operator to activate VOLTE for the mobile phone card, and then go to the mobile phone settings --**--enable the VOLTE voice call function.

Note: After it is successfully enabled, the word HD will be displayed in the notification bar of the mobile phone.

At present, OPPO R9 and R9Plus mobile phones support the VOLTE function.

VoLTE is an IMS-based voice service.

Voice over LTE is an IP data transmission technology that does not require a 2G 3G network and all services are carried on a 4G network, which can unify data and voice services under the same network. In other words, the 4G network not only provides high-speed data services, but also provides high-quality audio calls, the latter of which requires VoLTE technology.

Maybe when you set it,It belongs to the default option,That is, you have to set it yourself,And it can't be it automatically out of Oak,I'll find it myself,You can go to the Internet to check the sleeper or the product about the mobile phone and that series of information or something,It's very simple,You find it yourself.,Go to search for it.,You search for your phone model.,And then by the way.。 Then you casually, and then you can check and inquire about it, and then you can go to the server professional of the oppo phone. Thanks over.

1. Restart the phone to see if it recovers; 2. The third-party camera software cannot be used, it is recommended to replace or uninstall and reinstall it to eliminate software problems; 3. Upgrade the system and eliminate the possibility of system abnormalities (enter the words "upgrade system" to query the upgrade system method); 4. Back up important data (contacts, text messages, etc.), and then restore factory settings (Settings - System).

There are a lot of recording software in the Android system, and the best one is Pinocchio call recording, and there are Android phones to try.

Call the operator for free**, there is a word recording on the page when you call, and you can record it when you click it.

Unicom didn't turn it on, and it didn't work if it fell back to the 3G network.

"Wo 4G+" is a comprehensive strategic upgrade carried out by China Unicom to accelerate the development of 4G. The upgrade focuses on the three highlights of "more complete 4G network coverage, doubling the network, and better call experience", and strives to build an industry-leading 4G boutique network. Through the sharing and doubling of network coverage, the user experience is more comfortable; Through the transparency and safety of product design, users can be more assured of consumption; Through the simplicity and convenience of the service experience, the service for users will be more intimate, and it will bring users unprecedented new changes, new feelings and new experiences.

Some mobile phones have a magic sound function, that is, when you are on a call, there is an operation option, you may have a magic sound option when you look for it, and then go play it yourself. But if you don't have that option, you can't help it.

Add nasal accents to speak by yourself.

No, now the phone doesn't let the call change tone.

Card settings in the settings:

Hello according to your situation, it may be that the system is abnormal, it is recommended to back up the data, and the phone is double-clear to see!! The specific steps of Shuangqing are as follows: after shutting down, press and hold the power button and the volume down button at the same time, and enter the recovery mode after 5 seconds - the recovery interface appears, use the volume up and down keys to select "Clear Data Restore Factory Settings" The power button is OK and wait for the end - Use the volume up and down keys to select the "Clear System Cache" power button to confirm and wait for the end, and finally select Restart.

Note that Shuangqing will erase all data, so be sure to back up important data in advance!

Hello, this may be a system problem, you can try to back up the data after restoring the factory settings to see below!! Or double clear and reflash the firmware to take a look.

If you have any other questions, you can enter the OPPO enterprise platform to ask customer service questions!