Power-aware and QOS-aware resource management in wireless networks
Abstract (Summary)iii With the advent of third generation wireless infrastructures and the rapid growth of wireless communication technology, people with battery powered mobile devices will have high-speed wireless data access at any time any place. However, due to the unique characteristics of wireless networks such as dynamic channel condition and limited energy supply, we cannot directly apply the existing resource management schemes designed for wired networks to wireless systems. Therefore, new techniques are needed for efficient resource management in wireless networks. In this thesis, we have designed and evaluated new scheduling schemes and medium access control (MAC) protocols that focus on power efficiency, QoS provision, fairness and bandwidth utilization in wireless networks. We first concentrate on prolonging the battery life of the mobile terminal by reducing the power consumption of the wireless network interface. Each mobile terminal uses its proxies to buffer data so that the wireless network interface can sleep for a long time period and tolerate the state transition delay. The base station applies our proposed scheduling schemes to service each flow in a power efficient way without loss of QoS requirements, and alleviates the impact of channel errors on QoS provision. We then design the absence compensation fair queuing (ACFQ) model to improve service differentiation under bursty data traffic in wireless networks. To achieve good service differentiation without loss of QoS provision for each flow, an absence compensation model and an error compensation model are integrated into ACFQ. By the iv well-controlled absence compensations, ACFQ can provide much better service differentiation than the legacy fair queuing models (e.g. the weighted fair queuing) under bursty data traffic. Finally, we propose the relay-enabled MAC protocols in the context of IEEE 802.11 based wireless networks. With the physical layer multi-rate capability, data can be transmitted at different rates according to the channel condition. As a result, when the transmission rate between the sender and the receiver is low, while high rates are available between the sender and the relay node and between the relay node and receiver, data can be delivered much faster through relay. We design protocols that enable the relay mechanism in the point coordination function and the distributed coordination function respectively. Many optimizations are used to reduce control overhead and deal with channel utilization issues. Throughout our study, we have paid considerable effort to deal with design difficulties introduced by limited power supply, dynamic channel conditions, effect of interference or capture, and stringent QoS requirements. We hope that such effort has allowed practical solutions for achieving high-speed data access and providing good QoS in wireless networks. Meanwhile, we theoretically analyze our schemes and extensively evaluate the performance via simulations to give a detailed understanding of the characteristics of our schemes. We hope the results have a long, valuable life.
School Location:USA - Pennsylvania
Source Type:Master's Thesis
Date of Publication: