[[abstract]]The emerging IEEE 802.16e Worldwide Interoperability for Microwave Access (WiMAX) network is one of the most promising solutions to provide ubiquitous wireless access with high data rates, high mobility, and wide coverage. In the project we study some significant problems in WiMAX mobile networks, including bandwidth reservation for handoffs, bandwidth request/allocation for variable-rate real-time services, and pricing for WiMAX/WiFi integrated networks. In IEEE 802.16e BWA networks, it is important to assure seamless handover for mobile subscriber stations to support quality of services (QoS). For the purpose, the base station needs to reserve a certain amount of bandwidth for handover connections in order to decrease handoff latency and dropping probability. In the first year of this project, we will deeply investigate the bandwidth reservation problem by theoretical and numerical analyses, and we will propose our bandwidth reservation scheme based on the analyses. Our scheme will further consider the network loads to dynamically adjust the call-admission-control (CAC) criteria and the reserved bandwidth for handover connections to both guarantee QoS for handoffs and increase the system utility. In recent years, as the technologies of broadband wireless access (BWA) advance, the needs of wireless multimedia services, such as audio and video streaming applications, IPTV, and video conferencing are increased dramatically. In particular, providing voice services in WiMAX networks is expected to be an important application contending with the traditional telecommunication services in the future. For VoWiMAX services, our project in the second year will focus on the design of a dynamic bandwidth request-allocation and scheduling mechanism for the Extended-real-Time Poling Service (ertPS). The type of ertPS service is primarily used for variable-rate real-time applications, such as VoIP services with silence compression. We will investigate the QoS of VoIP applications based on the ertPS service in IEEE 802.16 network and design a novel bandwidth request-allocation scheme for the ertPS service. In the first two years, we focus on the study of technical problems of WiMAX including the CAC problem and a dynamic bandwidth request-allocation problem; in the third year of our project, we set our sight on a commercial problem, pricing, in an integrated WiMAX/WiFi Network. The 802.11 wireless local area network (WLAN) has already become a mature and popular WLAN technology today. With the rapidly develop of WiMAX technologies, the integration of WiFi and WiMAX networks will be an increasingly important issue in the near future. We plan to apply the dominant strategy equilibrium of a dynamic game, which is based on the game theory, to find the optimal bandwidth-allocation schemes and pricing policy in such the heterogeneous network. With our investigations on the problems of bandwidth reservation for handoffs, bandwidth request/allocation for variable-rate real-time services, and pricing for WiMAX/WiFi integrated networks, we hope to thoroughly provide an in depth view about the system design of IEEE 802.16 WiMAX in the future.