Policy and Charging Enforcement Function (PCEF) is a functional unit in the PCC architecture, Policy Control and Charging (PCC), of Long Term Evolution ( LTE), which is interfaced and works closely with the Policy and Charging Rules Function( PCRF).
The PCEF is implemented in the Serving Gateway( SGW) and implements the decisions made by the PCRF and provides the PCRF with subscriber data and access information. For dynamic policy changes, the PCEF functional unit can respond directly to messages from the PCRF functional unit and install, modify, or remove Policy Control and Charging (PCC) rules. With static policy management, decisions are made without the intervention of the PCRF.
In the Evolved Packet System( EPS) of LTE networks, the Policy and Charging Enforcement Function (PCEF) is a functional unit of the PDN Gateway(PDN- GW), which provides access from external data packet networks to mobile networks.