Policy decision point for QoS and charging control in LTE/EPC.
Description
The Policy and Charging Rules Function (PCRF) is the policy decision point in the EPC. It makes policy decisions based on service data flow information, subscription information, and operator-defined policies.
The PCRF provides network control regarding service data flow detection, gating, QoS, and flow-based charging. It interacts with the P-GW (via Gx) and AF (via Rx).
Purpose & Motivation
The PCRF was introduced to enable dynamic policy and charging control, allowing operators to:
- Differentiate service quality by subscription - Enable real-time charging - Support application-aware policies (e.g., VoLTE prioritization) - Implement fair usage policies
Key Features
- ✓Policy decision making
- ✓QoS authorization
- ✓Gating control
- ✓Flow-based charging rules
- ✓Application function coordination