SCRIBE: self-organized contention and routing in intelligent broadcast environments

Large-scale sensor networks (LSSNs) are systems with a very large number of networkable sensors deployed randomly over an extended environment, rendering it observable. These randomly deployed networks need no pre-design and configure themselves through a process of self- organization. The purpose of our research is to consider how reliable, robust and scalable location-addressed communication can be assured in LSSN systems built from large numbers of inexpensive and unreliable nodes with limited capabilities using only broadcast communication. We present viable broadcast-based protocols for channel access and network organization. We focus on the situation where the transmission radius of individual nodes is much smaller than the size of the system, so that most messages need a large number of "hops" to reach their destination. In view of this, and given the unreliable nature of the nodes, we consider whether an inherently redundant intelligent broadcast scheme can provide sufficient message reliability. This bottom-up approach to communication is shown to provide reliable communication at the system level and to outperform more complex model-based approaches.