EPC Architecture

EPC Network Architecture

There are several functional entities within the core Evolved Core Network. Within the user plane the core network is the gateway between the access network and the PDNs (e.g., the Internet) that support the interfaces, mobility needs and the differentiation of QoS flows. The gateway may be split in two separate nodes with an optional S5 interface. The two logical gateway entities are the Serving Gateway (S-GW) and the PDN Gateway (P-GW).

The Serving Gateway (S-GW) acts as a local mobility anchor, forwarding and receiving packets to and from the eNodeB currently serving the UE.
The PDN Gateway (P-GW) interfaces with the external PDNs, such as the Internet and IMS. It is also responsible for several IP functions, such as address allocation, policy enforcement, packet classification and routing, and it provides mobility anchoring for non-3GPP access networks.

The control plane functions are performed by the MME which is connected to the gateway via the S11 interface.

The PCRF makes policy decisions based on information obtained via the Rx interface. It confirms that the information received is consistent with policies defined in the PCRF. The PCRF will authorize QoS resources and will decide if new resources are required for existing connections. PCRF mechanism is used also in 3G network.

















http://4g360.com/profiles/blogs/evolved-packet-core-architecture-and-network-element?utm_source=All+Contacts&utm_campaign=04dac46001-July_2013_WiMAX_Forum_Monthly_Newsletter7_30_2013&utm_medium=email&utm_term=0_9db850706d-04dac46001-&ct=t%28July_2013_WiMAX_Forum_Monthly_Newsletter7_30_2013%29&mc_cid=04dac46001&mc_eid=[UNIQID]