ABSTRACT
Sensor networks are expected to be deployed in large numbers for applications, such as environmental monitoring, surveillance, security, and precession agriculture [1-4]. Each sensor node consists of a sensing device, processor with limited computational capabilities, memory, and wireless transceiver. These nodes are typically deployed in inaccessible terrain in an ad hoc manner. Once deployed, each sensor node is expected to periodically monitor its surrounding environment and detect the occurrence of some predetermined events. For example, in a sensor network deployed for monitoring forest fires any sudden surge in the temperature of the surrounding area would be an event of interest. Similarly, in a sensor network deployed for surveillance any moving object in the surroundings would be an event of interest. On detecting an event a sensor node is expected to report the details of the event to a base station associated with the sensor network. In most cases, the base station might not be in direct reach of the reporting nodes. Hence, sensor nodes need to form a multihop wireless network to reach the base station. A medium access control protocol and a routing protocol are essential in setting up such a wireless network. In this chapter we present an overview of design challenges associated with routing in sensor networks and some existing routing protocols.
