In a 5G system, when the NG interface or certain parts of the NG interface need to be reset, the NG-RAN node will be notified; when the AMF processes overload, an overload message will also be sent to the NG-RAN node to notify the gNB to start the load management process; the specific definitions of these messages are as follows;
1. NG reset messages are sent by NG-RAN nodes and AMF to request the reset of the NG interface or certain parts thereof.
2. The NG RESET acknowledgment message is jointly sent by the NG-RAN node and the AMF as a response to the NG RESET message.
3. NG RESET Confirmation Message: This message is jointly sent by the NG-RAN node and the AMF as a response to the NG RESET message.
4. Error indication messages are sent by NG-RAN nodes and AMF to indicate that an error has been detected in the node.
5. The overload start message is sent by the AMF to indicate to the NG-RAN node that the AMF is overloaded.
6. The overload stop message is sent by the AMF to indicate that the AMF is no longer overloaded.
