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