Power Mode Scheduling for Ad Hoc Network Routing

Abstract

An ad hoc network is a group of mobile wireless nodes that cooperatively form a network among themselves without any fixed infrastructure. Each node in the ad hoc network forwards packets for other nodes, to allow nodes not within direct wireless transmission range to communicate, using a routing protocol. Increasingly, power consumption within ad hoc networks is becoming a core issue for these low-power mobile devices. This thesis focuses on a novel approach for energy conservation within the ad hoc network routing protocol. I develop and evaluate two types of mechanisms for reducing this power consumption by the routing protocol in the network. The routing protocol uses information from packets received promiscuously to improve routing performance. The first part of this work is a strategy for reducing this use of promiscuous mode intelligently, thereby saving energy but retaining all the benefits of being in promiscuous mode. In addition, a wireless card in sleep mode expends an order of magnitude less power than in idle mode, but no packets can be sent or received while in sleep mode. In the second part of this work, I propose two algorithms for scheduling transition from idle mode to sleep mode. We apply probabilistic mechanisms as a useful tool, thereby trading energy for a minimal performance loss. Performance evaluation of these strategies show significant reduction in power usage, with only a slight decrease in performance.