Turn on the hot spot, why is the call disconnected?

You need to check whether your cell phone signal is full when you are disconnected during the call. If the signal is unstable, it is normal to disconnect the network. The second possibility is that the mobile phone does not support VoLTE calls.

The previous 4G network can only provide high-speed network and does not support voice service. Therefore, whether it is TD-LTE (mobile 4G) or FDD-LTE (possibly Unicom/Telecom 4G), when a call comes in, the system will automatically disconnect the 4G signal, automatically fall back to the 2G/3G signal to complete the voice call, and then switch back to the 4G network after receiving the call. In other words, the current 4G data service (4G Internet access) cannot be carried out simultaneously with voice calls.

When you are watching news on the 4G network and suddenly want to call your friend (or your friend wants to call you), the mobile phone needs to switch the 4G network to the 2G/3G mode first, and the switching time is about 2 seconds to 15 seconds (the specific time depends on the optimization of the mobile phone and the operator). In other words, during the signal switching, if your phone can't be dialed out and the other party can't get in, your 4G network will be automatically disconnected.

At present, many operators have been able to support VoLTE calling scheme, which is an end-to-end voice scheme based on 4G network, which can bring lower access delay (waiting time after dialing) and the probability of dropped call is close to zero.

Of course, VoLTE calls also need mobile phone support. Turn on the VO-LTE switch during setup-call, and you can talk on the Internet at the same time without disconnection.

The specific opening steps are as follows:

Call the operator first, mobile 10086, Unicom 100 10, telecom 10000, and ask the customer service to open 4G+ HD voice. This function is generally free.

Then turn on the phone settings (take Xiaomi phone as an example)

Enter mobile network settings

Then you can see that there is an "Enable VoLTE" HD call switch at the bottom of the SIM card information. It should be noted here that if it is a dual card, both cards should be opened.

When everything is done, you can make a happy phone call and surf the Internet.