What happened when the mobile phone signal changed from 4g to 2g?

The reasons why 4g network becomes 2g network: 1. There is no 4G signal coverage nearby or the signal is poor; 2. VoLTE is not activated; 3. The mobile phone is in arrears; 4. The mobile phone does not support 4G network; 5. The mobile phone The SIM card fails; 6. The mobile phone system crashes; 7. The mobile phone case interferes with the signal; 8. There is dirt or oxidation on the metal surface of the SIM card.

The reason why 4g network becomes 2g network:

1. There is no 4G signal coverage nearby or the signal is poor. However, there is 2G signal coverage, and mobile phones can only access the 2G network. Nowadays, the level of optimization of 4G network construction is already high, especially in places where a large number of users gather, such as cities, counties, and villages; this situation may only exist in desolate wilderness and high mountain areas.

2. VoLTE is not activated. If the user does not activate VoLTE, making or receiving calls will fall back from 4G to 2G. This technology is called voice fallback (CSFB).

3. The mobile phone is in arrears. If the mobile phone is in arrears: the 4G network cannot be used, the mobile phone will turn off the 4G network and turn on the 2G network. The recharged phone bill will be restored.

4. The mobile phone does not support 4G network. In this case, the only option is to replace the phone.

5. The SIM card of the mobile phone is faulty. In this case, you need to go to the business hall for SIM testing in time to avoid affecting your use.

6. The mobile phone system crashes. You can restart your phone or set airplane mode, wait 5 seconds and then turn off airplane mode to restore the signal.

7. The mobile phone case interferes with the signal. Whether to use metal protective cases, magnetic protective cases, magnetic brackets and other accessories. Metal and magnetic materials can easily interfere with signal reception. It is recommended to remove the accessories for inspection.

8. There is dirt or oxidation on the metal surface of the SIM card. It will cause unstable signal reception and can be checked after cleaning.

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