Top-down clustering based self-organization of collaborative wireless sensor networks

Abstract

The proposed cluster tree based routing strategy facilitates both node-to-sink and node-to-node communication. Hierarchical addresses that reflect the parent-child relationship of cluster heads is used to route data along the cluster tree. Utilization of cross-links among neighboring cluster heads and a circular path within the network approximately doubles the capacity of the network. Under ideal conditions, this approach guarantees delivery of events/queries and has a lower overhead compared to routing strategies such as rumor routing and ant routing. The cluster tree formed by our algorithm is used to identify and form Virtual Sensor networks (VSNs), an emerging concept that supports resource efficient collaborative WSNs. Our implementation of VSN is able to deliver unicast, multicast, and broadcast traffic among nodes observing similar events, efficiently. Efficacy of the VSN based approach is evaluated by simulating a subsurface chemical plume monitoring system. The algorithm is further extended to support the formation of a secure backbone that can enable secure upper layer functions and dynamic distribution of cryptographic keys, among nodes and users of collaborative sensor networks.