- Figure shows the network architecture of the Evolved Packet Core (EPC). The EPC consists of three main nodes: the Mobility Management Entity (MME), the Serving Gateway (SGW) and the Packet Data Network Gateway (PGW). The MME may be co-located with the SGW, and the SGW may be co-located with the PGW. Hence, the standard allows a completely collapsed ‘one-node’ core network or a distributed (easily scalable) core network, or any possible ‘combination’ in-between.
- The MME connects to the E-UTRAN via the S1-MME interface and is present solely in the CP. It is responsible for handling mobility and security procedures, such as network Attach, Tracking Area updates (similar to Location/Routing Area updates) and authentication. The MME also connects to the SGSN via the S3-interface.
- The SGW connects to the E-UTRAN via the S1-U interface and is present solely in the UP. Its prime responsibility is routing and forwarding of user IP-packets. It acts as a UP anchor when the UE moves between 3GPP radio access technologies (S4-interface).
- The PGW connects to the SGW via the S5-interface and to external packet data networks (or IMS) via the SGi-interface. It is responsible for the enforcing of QoS and charging policies. It also acts as a UP anchor when the UE moves between 3GPP and non-3GPP radio access (S2-interface).
- It should be noted that additional network nodes/functions, not shown in figure , might be present as well. For example, a Packet Data Gateway (PDG) is needed for non-trusted IP access and a Policy and Charging Rules Function (PCRF) is required for IMS controlled QoS and charging mechanisms.
Network Architecture in LTE, anchor when the ue moves between, gpp radio access, qos and charging, radio access, network architecture of the Evolved Packet Core
Network Architecture in LTE
Network Architecture in LTE, interface, networkattach, cdma, epc, lte, mme, packet core, pgw, pn, sgw, telecom