Question: How are non-UE associated signalling messages associated with an Xn-C interface instance in a shared radio access network?
Option 1: By including a Cell Identity in the XnAP message.
Option 2: By allocating values for the corresponding NG-RAN node UE XnAP IDs.
Option 3: By using a separate Xn-C interface instance for each logical node.
Option 4: By including an Interface Instance Indication in the XnAP message.
Explanation: In a shared radio access network, non-UE associated signalling messages are associated with an Xn-C interface instance by including an Interface Instance Indication in the XnAP message. This allows multiple logical nodes to share the same physical radio resources and signalling transport resources.