Energy-efficient routing protocols in ad hoc networks

Wireless ad hoc networks consist of a collection of mobile nodes that dynamically form a network without the use of any existing network infrastructure. In such networks, each mobile node can serve as a router. Packet delivery is achieved through a single-hop transmission if the communicating nodes are neighbours, otherwise packets can be routed through multiple intermediate nodes. Energy efficiency is important issue in ad hoc networks, where mobile nodes are powered by batteries and it may not be possible to recharge them during a session. The limited battery lifetime can cause one or more links in the network to fail and affect the operation of the network. To maximize the network lifetime, traffic should be routed such that the energy consumption is minimized. We present a survey of energy-efficient routing approaches that have been proposed for various types of ad hoc networks, including mobile ad hoc networks (MANETs), ad hoc mesh networks, and cognitive radio networks. We discuss the main features of each approach and analyse their benefits and operation strategies.