US Patent 11218519 Service based P-CSCF discovery

The present disclosure enables a UE (100) to discover a P-CSCF (85) in the IMS network based on the services offered by the P-CSCF or the area served by the P-CSCF (85) when it establishes a data session. The P-CSCF (85) registers with a discovery node (70) in the wireless communication network (10) and provides relevant information about the P-CSCF (85) to the discovery node (70), such as the type of services provided, its network address and/or FQDN, a list of cells supported, and a list of tracking areas supported. When a request is received to establish a session with the IMS for a UE, the SMF (45) in the wireless communication network (10) queries the discovery node (70) to fetch the P-CSCF (85) information and forwards the P-CSCF information to the requesting UE. The UE (100) selects a P-CSCF (85) to use when it initiates IMS registration.