1. Please check whether the number of signal bars of your mobile phone is normal when there is a problem. If the signal strength is weak or fluctuates greatly, please consult with the operator to improve the signal coverage quality.2. Do you have the same problem with your colleagues or friends? If yes, it may be a problem with the local network. Contact the local operation.3. Turn off the 4G switch of the mobile phone, because the 4G network in some areas is unstable, and thus the communication interruption fault may occur.4. Is the standard Nano card in your operator's phone card? If the cut card may cause poor slot contact and communication problems such as lack of network or weak signal, it is strongly recommended to replace the original Nano operator phone card.5. The fault may be caused by unstable software system. It is recommended that you back up the data and upgrade your mobile phone to the latest version. If the data is already backed up in the latest version, restore the factory settings, and check whether the fault persists. 6. If a call drop or interruption occurs on your mobile phone anywhere, the hardware of the mobile phone may be faulty. It is recommended that you check the mobile phone at a site.