Energy conservation schemes for ad hoc networks
Chavalit Srisathapornphat, Chien-Chung Shen · 2004
Ad hoc networks consist of mobile nodes that autonomously establish connectivity via multihop wireless communications. Without relying on any existing, pre-configured network infrastructure or centralized control, ad hoc networks are useful in many situations where impromptu communication facilities are required. For many applications, extended network lifetime is crucial to their successful operations. However, mobile nodes are normally powered by limited battery supply, and in most cases, it is impractical to replenish those exhausted batteries. Therefore, energy conservation is of paramount importance to mobile ad hoc networks. In this dissertation, we investigate various techniques to conserve energy of ad hoc networks. First, we introduce the Coordinated Energy Conservation (CEC), which relies on a backbone infrastructure and conserves energy of ad hoc networks by switching idle non-backbone nodes into the sleep mode. We then describe the Ant-based Energy Conservation (ABEC) protocol, which utilizes the biological metaphor of swarm intelligence to balance energy conservation and network forwarding performance. While our simulation studies show that both CEC and ABEC perform equally well in conserving energy and extending the network operational lifetime and still maintaining comparable application forwarding performance with respect to a network without energy conservation, ABEC does not require any explicit synchronization or coordination among ad hoc nodes as used in CEC. In addition, we present a hybrid topology control framework based on transmission power adjustment, termed the Cluster-based Topology Control framework (CLTC). CLTC uses a centralized algorithm within a cluster and between adjacent clusters to achieve strong connectivity, and yet achieves the scalability and adaptability of a distributed approach with localized information exchange between adjacent clusters. We analyze and evaluate CLTC in terms of effectiveness, scalability, and application forwarding capability. Finally, we study energy consumption behavior and data forwarding performance of various RTS/CTS-based directional virtual carrier sensing schemes through both analysis and simulation experiments.