US Patent 11316708 Gx session recovery for policy and charging rules function

A Policy and Charging Rules Function (PCRF) can maintain a mapping table that associates gateway identifiers of gateways in a packet core network with corresponding IP address ranges. Based on an IP address of user equipment (UE), the PCRF can identify which of the IP address ranges in the mapping table over the UE's IP address, and which gateway identifier is mapped to that IP address range. The PCRF can accordingly contact the identified gateway to establish a Gx session for the UE with the gateway, such as restoring a previous Gx session or establishing a new Gx session.