 transport functions. Addressing schemes used in E-UTRAN and EPC are not associated with the addressing schemes of transport 2.8 Overview of 3GPP evolved packet core network architecture GERAN GPRS Core Network UTRAN Evolved Packet Core Network Operator IP E-UTRA MME/UPE 3GPP Anchor SAE Anchor Services (IMS, PSS, etc.) Trusted non- 3GPP IP Access WLAN Access WLAN IP Access FIGURE 2-8 The 3GPP evolved packet core network reference model [32,33] functions. The fact that some E-UTRAN or EPC functions reside in the same equipment as some transport functions does not make the transport functions part of the E-UTRAN or the EPC; The mobility for RRC connection is fully controlled by the E-UTRAN; The interfaces should be based on a logical model of the entity controlled through this interface; One physical network element can implement multiple logical nodes. Figure 2-8 illustrates the EPC network reference model. The functional entities and their corre- sponding interfaces are defined as follows [32,33]: Functional Entities Mobility Management Entity (MME) manages and stores UE idle state context (e.g., UE/user identities, UE mobility state, and user security parameters). It generates temporary identities and allocates them to UEs. It checks authorization as to whether the UE may camp on the Tracking Area (TA) or on the Public Land Mobile Network (PLMN). ix It authenticates user. User-Plane Entity (UPE) terminates the idle-state UE, downlink data path and triggers/initiates paging when downlink data is available for the UE. It manages and stores UE context A Public Land Mobile Network (PLMN) is a network established and operated by an administration or by a recognized operating agency for the specific purpose of providing land/mobile telecommunications services to the public. CHAPTER 2 WiMAX Network Architecture (e.g., parameters of the IP bearer service or network internal routing information). It performs replication of the user traffic in case of interception. Evolved Packet Data Gateway (ePDG) secures the access of 