PCF: Policy Control Function

PCF — The Policy Brain

The Policy Control Function replaces the 4G PCRF and serves as the central policy engine for the 5G core. It creates and manages three distinct types of policies. Access and Mobility policies delivered to the AMF control service area restrictions, RAT frequency selection priority, and RFSP index values. Session Management policies delivered to the SMF define QoS parameters, charging rules, gate control, and traffic steering for PDU sessions. UE policies sent directly to the UE include URSP rules that tell the UE which network slice and DNN to select for different application types.