network namely radio access, transmission, core and OSS, services and devices. Thus after individually discussing all these elements it is important to discuss the network from a holistic angle. Thus, Chapter 11 will focus on providing end-to-end architecture of the next generation of cellular and broadband networks. The interworking with WLAN is not discussed and readers can refer to [1] for details on this topic. The other key areas that are discussed are mobility management or interoperability between the different radio technologies and Fixed Mobile Convergence (FMC). Sections 11.2 and 11.3 describe the end-to-end network architecture of EPS (Evolved Packet Sys- tem) and WiMAX systems respectively. Various aspects of interworking are discussed in Sections 11.4-11.8, including mobility management in EPS and WiMAX, interoperability between EV-DO, EPS, and WiMAX and challenges associated with interworking. And Section 11.9 describes Fixed Mobile Convergence from networks, devices and services perspectives. E2E EPS Architecture EPS networks are designed on the basis of Flat Architecture - having a minimum of network elements as compared to their predecessors GSM and HSPA. EPS (Evolved Packet System) consists of E-UTRAN (Enhanced UTRAN) and EPC (Evolved Packet Core) as shown in Figure 11.1. E-UTRAN only consists of a Node-B called Evolved Node-B and it doesn't have separate physical RNC (Radio Network Controller) like HSPA. eNode-B interfaces with user terminals with most of the functionality of RNC. The merger of Node-B and RNC reduces footprint and latency due to fewer hops for transmission and allows distribution of RNC processing load into multiple e-NodeBs. The all-IP core EPC is the evolution of the legacy GPRS architecture with additional features to improve performance, support E-UTRAN access, and support integration with non-3GPP radio technologies such as WLAN and WiMAX. EPC can be accessed by both GSM family networks and non-3GPP access technologies such as EV-DO, WLAN, and WiMAX. All 3GPP-specific acce