Energy-efficient routing and control mechanisms for wireless ad hoc networks.

摘要

The advantage of using variable-range transmission control is twofold.; First, we show that the use of variable-range transmission approaches achieve lower transmission power levels compared with the minimum transmission power levels that can be obtained by common-range transmission based routing protocols. Second, we show that a variable-range transmission policy can maintain constant per-node capacity even when more nodes are added in a fixed area network. Third, we derive a model that approximates the signaling overhead of a routing protocol as a function of the transmission range and node mobility for both route discovery and route maintenance.; Based on the results and insights from the first part of the thesis we propose a network level routing scheme called PARO. We present the design, analysis and implementation of PARO, which represents a new approach to dynamic power controlled routing that helps to minimize the transmission power needed to forward packets between devices in wireless ad hoc networks. Using PARO, one or more intermediate nodes called “redirectors” elects to forward packets on behalf of source-destination pairs thus reducing the aggregate transmission power consumed by wireless devices. We use a combination of analysis; simulation and results from an experimental wireless testbed implementation of PARO to show the performance of our approach. We discuss the limitations of existing radio and MAC technology in realizing the initial goals of the protocol using off-the-shelf technology.; In the final part of the thesis we investigate the feasibility of supporting traditional QOS performance (e.g., bandwidth or delay assurances) in a network that is based on variable-range transmission control and PARO style routing protocols. Specifically, we study the impact of PARO on throughput and end-to-end delay and study its implementation for wireless ad hoc networks using IEEE 802.11 and an alternative power controlled multiple access scheme. We show the limitations of these MAC protocols under single and multihop operations. We then propose QOS enhancements to the original PARO protocol called QoS-PARO that builds new mechanisms into the original PARO system for a class of applications that wish to tradeoff better QoS performance for sub optimal power savings. (Abstract shortened by UMI.)