Self-Organizing Distributed Sensor Networks

Advances in CMOS IC and micro electrical-mechanical systems (MEMS) technology are enabling construction of low-cost building blocks each of which incorporates sensing, signal processing, and wireless communications. Collections of these integrated microsensor nodes may be formed into sensor networks in a wide variety of ways, with characteristics that depend on the specific application – the total number of nodes, the spatial density, the geometric configuration (e.g., linear vs. areal), topographic aspects (e.g., smooth vs. rough terrain), and proximity and proportion of user/sink points. The power of these distributed sensor networks will be unleashed by means of their ability to self-organize, i.e., to bootstrap and dynamically maintain organizational structure befitting the purpose and situation that is presented without the need for human assistance. A prototype sensor system and networking protocols are being developed under the DARPA/TTO AWAIRS Program and are described. The current system is capable of self-organizing the communications among nodes so as to bring the initial system on-line via discovery mechanisms, establish needed end-to-end circuits that provide information to and commands from end users, allow new nodes to be added and reconfigure when existing nodes fail, and to quickly evolve so as to achieve these functions via low power operation. Improved network protocols have been designed and simulated that are expected to enhance performance in bootstrap and routing, and these will be integrated into the existing modular system architecture. Self-organizing procedures for cooperative signal processing and resource management are also being incorporated into the AWAIRS microsensor network system.