Overview

This dissertation, Mobility and Radio Resource Management in Heterogeneous Wireless Networks by Xiaoshan, Liu, 劉曉杉, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of the thesis entitled Mobility and Radio Resource Management in Heterogeneous Wireless Networks submitted by Xiaoshan Liu for the degree of Doctor of Philosophy at the University of Hong Kong in October 2006 Future generation wireless communication systems are characterized by ubiquitous access and Quality of Service (QoS) guarantees. They consist of IP-based heterogeneous wireless networks (HWN) with overlaid coverage to provide users with a broad range of access services. In a wireless communication system, mobility and radio resource management are essential system functions to support seamless global roaming. However, the functions in HWN systems are very different from those employed in traditional homogeneous wireless networks, and presents new challenges. First, the complexity and large dimension of an HWN system adds to the latency of signaling when signals traverse the component networks. When mobile users make handoffs in HWN, long handoff delay and heavy packet loss will be caused by this prolonged signaling exchange, seriously compromising QoS. Second, every component network is deployed following its own architecture and the characteristics of its particular technology. Therefore, the underlying radio resource management (RRM) functions need to be coordinated in admission control to improve users' experience and system performance. In this study, we propose methods in architecture, protocol and algorithms to solve the above problems in an HWN system. We first introduce a mobility management architecture with an Edge Mobility Agent (EMA) to improve the performance of handoffs between different networks. In the architecture, an EMA is introduced at the edge of the low-tier network to provide a transition area for handoff signaling exchange that effectively eliminates delay and packet loss during a vertical handoff. We also propose a Service Differentiated Handoff Protocol (SDHP) to handle handoffs between cells of the same network. In SDHP, we classify connections' QoS requirements into two classes and propose to use different handoff schemes to handle these connections to satisfy their different QoS requirements. With SDHP, we strike a balance between users' handoff experience and efficiency of radio resource utilization. To optimize radio resource utilization and access selection, we propose two joint admission control schemes to allocate connection requests to different component networks. In one scheme, the bandwidth to be allocated for each user is adaptive to the current resource utilization of every access network. A profit function is established to evaluate the profits gained from a handoff and the target network is selected accordingly. In another scheme, we formulate the joint admission control problem as a Semi- Markov Decision Process, and employ bandwidth adaptation to improve users' experience. We propose to use multi-agent system reinforcement learning to optimize SMDP. With this method, the system will learn an optimal policy from its experience that matches the characteristics of system capacity and user traffic, and maximizes a policy-based system reward. With the above proposals in architecture, protocol and algorithms, we provide a solution combining mobility and radio resource management and realize seamless global roaming with QoS support in HWN systems. (Total number of words: 457) Signature _________________ Xiaoshan Liu

Full Product Details

9781361471494

Table of Contents

Reviews

Author Information

Tab Content 6

Countries Available