SYREN: Synergistic Link Correlation-Aware and Network Coding-Based Dissemination in Wireless Sensor Networks

Rapid flooding is necessary for code updates and routing tree formation in wireless sensor networks. Link correlation-aware collective flooding (CF) is a recently proposed technique that provides a substrate for efficiently disseminating a single packet. Applying CF to multiple packet dissemination poses several challenges, such as reliability degradation, redundant transmissions, and increased contention among node transmissions. The varying link correlation observed in real networks makes the problem harder. In this paper, we propose a multi-packet flooding protocol, SYREN, that exploits the synergy among link correlation and network coding. In particular, SYREN exploits link correlation to eliminate the overhead of explicit control packets in networks with high correlation, and uses network coding to pipeline transmission of multiple packets via a novel, single yet scalable timer per node. SYREN reduces the number of redundant transmissions while achieving near-perfect reliability, especially in networks with low link correlation. Test bed experiments and simulations show that SYREN reduces the average number of transmissions by 30% and dissemination delay by more than 60% while achieving the same reliability as state-of-the-art protocols.