Wireless Resource Management in IEEE 802.16 Networks

• Main Authors: Chen, Lien-Wu, 陳烈武
• Other Authors: Tseng, Yu-Chee
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/30843474417358311361

博士 === 國立交通大學 === 資訊科學與工程研究所 === 97 === The IEEE 802.16 standard for wireless metropolitan area networks (WMAN) is defined to meet the need of wide-range broadband wireless access at low cost. In this dissertation, we exploit spectral reuse and contention resolution of IEEE 802.16 networks. This dissertation is composed of three works. In the first work, we exploits spectral reuse in an IEEE 802.16 mesh network through bandwidth allocation, time-slot assignment, and routing tree construction. In the second work, we provides an analytic tool to evaluate the expected throughput of the route with spectral reuse in an IEEE 802.16 relay network. To further improve wireless resource utilization, the last work analyzes and compares two collision-resolution requesting schemes for best-effort (BE) traffics in IEEE 802.16 networks. In this dissertation, we first study how to exploit spectral reuse in resource allocation in an IEEE 802.16 mesh network, which includes routing tree construction, bandwidth allocation, time-slot assignment, and bandwidth guarantee of real-time flows. The proposed spectral reuse framework covers bandwidth allocation at the application layer, routing tree construction and resource sharing at the MAC layer, and channel reuse at the physical layer. To the best of our knowledge, this is the first effort which formally quantifies spectral reuse in IEEE 802.16 mesh networks and which exploits spectral efficiency under an integrated framework. Simulation results show that the proposed schemes significantly improve the throughput of IEEE 802.16 mesh networks. On the other hand, when mesh stations have mobility, they form a mobile ad hoc network (MANET) consisted of mobile relay stations. While many routing protocols have been proposed for MANETs based on different criteria, few have considered the impact of multi-rate communication capability that is supported by many current wireless products. Given a routing path, the second work provides an analytic tool to evaluate the expected throughput of the route with spectral reuse in a mobile relay network, assuming that hosts move following the discrete-time, random-walk model. The derived result can be added as another metric for route selection. Simulation results show that the proposed formulation can be used to evaluate path throughput accurately. To utilize the channel bandwidth more efficiently, the third work studies two collision-resolution requesting schemes for best-effort (BE) traffics in IEEE 802.16 networks. One is the exponential backoff scheme defined in the standard and the other is a piggyback mechanism enhanced by single-frame backoff, called the Request Piggyback (RPB) scheme. We analyze and compare their performance in terms of the request success probability and the packet delivery delay under Poisson traffic. The results show that the RPB scheme outperforms the exponential backoff scheme and can reduce request collision. Based on the designed scheduling, routing, and requesting schemes, we can further improve the efficiency of wireless resource management in IEEE 802.16 Networks.