Service-based architecture for internet protocol multimedia subsystem

A wireless communication node in a home network, comprising at least one processor that is configured to:

• determine an address of a serving network function for a roaming user device in a visited network;
• transmit a message to the serving network function in the visited network using the address via a home Security Edge Protection Proxy (SEPP) node and a visited SEPP node,
• wherein the message is configured to request information about one or more events associated with the roaming user device;
• and
• receive the information about the one or more events associated with the roaming user device from the serving network function in the visited network.

A wireless communication system in a home network, comprising:

• a second network function;
• and
• a proxy call session control function (P-CSCF), configured to:
• retrieve, from the second network function in the home network, an address of a serving network function in a visited network for a roaming user device in the visited network;
• transmit a message to the serving network function in the visited network using the address via a home Security Edge Protection Proxy (SEPP) node and a visited SEPP node,
• wherein the message is configured to request information about one or more events associated with the roaming user device;
• and
• receive the information about the one or more events associated with the roaming user device from the serving network function in the visited network.