PCRF as an EPC component

PCRF

From pre-LTE to Broadband

Layout

● History.● EPC as a concept.● Objectives of EPC.● Major functions of EPC.● Policy and Charging Control.● Benefits of Policy Control.● Where it fits in Broadband network.

History

I came, I saw, I conquered !

Julius Caesar

History - Basic Cellular Architecture

History - Cell Network Data

- GPRS (115 kbps)- EDGE (473 kbps)- UMTS (2 Mbps)- HSDPA (14 Mbps)- LTE (100 Mbps)

EPC - Need and Standardization

● Explosion in Data traffic and usage patterns.● Advance in microchip technology.● 3GPP.● Standardization benefits:

○ Freedom in choosing a vendor.○ Market Expansion, cost reduction, increasd benefits.

EPC

● 3GPP work on SAE (system architecture evolution) work item.

● SAE was responsible for EPC (Evolved Packet Core Network) as an all-IP solution.

● EPC is designed to support high bandwidth services at high data rates.

EPC - Objectives● New core network architecture to support high data rate

and reduced latency.● To support mobility between multiple heterogeneous

access systems (WiMAX, CDMA, 3G, 2G).● All IP architecture, to enhance the capability of 3GPP

systems to cope with rapid growths in IP data traffic.

EPC - Major Functions

● Authentication and Security.● Policy and Charging Control and QoS.● Packet Routing.● Mobility Management.● IP Address Allocation.

EPC - Policy& Charging Control and QoS● Segmented data plans.● Traffic & quota management.● Roaming.● Bill shock prevention.● Personalized alerts and promotions.● Congestion control.

EPC - Policy & Charging Control and QoS

SPR

● Subscription profile repository.● contains information such as user specific

policies and data needed for subscription-based policies and bearer level charging rules by the PCRF.

Online Charging System

● OCS● Credit management system for prepaid

charging.

Offline Charging System

● OFCS.● Receives events from the PCEF and

generates charging data records (CDRs) for the billing system.

Application Function

● AF● Offers applications that require the control

of IP bearer resources. ● Communicates with the PCRF to transfer

dynamic service information.

PCEF

● Enforces gating and QoS for individual IP flows on the behalf of the PCRF.

● Provides usage measurement to support customer charging.

● BRAS, BNG, ISG.

PCRF

● Policy and charging rules function.● Provides policy control and flow based charging control

decisions.● Receives session information from Application function

(AF) over Rx interface, subscription information from SPR over Sp interface as well as information from the access network via the Gx.

● Takes all the information and configured operator policies then creates a service session level policy decisions which are being enforced by PCEF.

Mapping to Broadband