An Energy-efficient Architecture for Wireless Sensor Networks

Networked embedded systems provide a versatile§computing platform for supporting surveillance§applications. These networks are typically left§unattended in harsh environments, making it§impossible to re-charge their batteries. Motivated by§the large scale of sensor deployment, the limited§capabilities of sensors, and the hostility of the§encompassing environment, we design distributed§protocols for topology management and network§synchronization. We address heavily-loaded networks,§in which sensors either periodically send their§reports to an observer, or respond to an observer's§query.§§We construct a hierarchical (clustered) network in§which a subset of nodes are elected as super-nodes§(cluster heads). These heads constitute the§routing infrastructure and aggregate data from their§cluster members. For load balancing, the super-node§functionality is rotated among the nodes. For nodes§deployed in harsh environments, we propose a§methodology for supporting robust connectivity and§multi-path routing. We also consider applications§and protocols that require node synchronization, and§design a framework for time synchronization in§multi-hop hierarchical networks.