Abstract:

Designing large-scale, unattended and long-lasting sensor networks requires rethinking about fundamental protocol design principles. Existing network protocols for medium access control, routing, and data collection are often based on network structures that are expensive to compute and maintain. Limited energy resources is one of the prime considerations in the design of large-scale sensor networks. We propose a new paradigm of protocol design termed "structure-free design" that relies primarily on dynamic and opportunistic forwarding decisions. It makes use of packet forwarding techniques based on MAC layer anycasting to take advantage of the broadcast nature of wireless channels.

This paradigm can be used to design protocols at various layers of the network stack. In particular, I will show how the MAC layer protocol in presence of duty-cycling, and the data aggregation protocol can be designed with provable performance bounds. These protocols have also been shown to provide significant performance improvement using TinyOS implementation on the Kansei testbed at OSU.

This work was motivated by observations made during our DARPA/NEST demonstration in 2004 where the world's largest sensor network of 1000 nodes was deployed over a 1.3 km x 0.3 km region for detection, classification and tracking of intruders. Further information on the DARPA project can be found here: http://ceti.cse.ohio-state.edu/exscal