Performance tradeoffs for routing in mobile ad hoc networks.

摘要

A mobile ad hoc network (MANET) is a self-organizing collection of wireless mobile nodes with dynamically changing topology. Given the plethora of MANET applications and their diverse performance needs, it is virtually impossible to design a routing protocol that could provide optimality in all the performance metrics. In Chapter 2 of the dissertation, we present a survey of 55 unicast MANET routing protocols that had been proposed with objectives to optimize particular performance metrics and satisfy specific application requirements. The objective of this dissertation is to explore the diverse performance tradeoffs encountered in MANET routing protocols and routing strategies. We consider the tradeoffs between the following performance metrics: hop count, delay, energy consumption, network (node) lifetime and stability.; In the first half of the dissertation, we address the issue of how to find a sequence of stable paths such that the number of route transitions incurred is as small as possible. We present a polynomial time greedy algorithm called OptTrans to determine the minimum required number of route transitions for a source-destination (s-d) session. We illustrate the tradeoff between hop count and the number of route transitions and show that the objectives of minimum hop and maximum stability conflict with each other. We then use algorithm OptTrans to derive benchmarks for the overall energy consumption for an s-d session in MANEs. We also show OptTrans is very general and explain how it can be extended to find a sequence of stable Steiner trees and stable connected dominating sets. We estimate the stability-delay tradeoff for common MANET routing protocols using a measure of the proximity of the protocol's actual stability and delay with respect to the optimal stability and delay computed under the same history of network topology changes.; In the second half of the dissertation, we study the tradeoff between network (node) lifetime and hop count, delay as well as energy consumption by proposing power-sensitive power control and on-demand recharging strategies. We also investigate the performance tradeoffs in on-demand power-aware routing; show how mobility can influence routing dynamics and reduce the route refreshing frequency.