Batch forwarding in wireless sensor networks

Many-to-one traffic pattern in wireless sensor networks (WSNs) causes significant performance degradation toward the sink. To mitigate this so called funneling phenomenon, researchers have proposed various mechanisms at different layers. In this paper, we consider batch forwarding or packet concatenation at network layer, and experimentally demonstrate how it improves the delivery ratio and end2end delay in WSNs. Accordingly, we first develop analytical models under simplified assumptions. We then conduct extensive actual experiments using TinyOS and IRIS motes from Crossbow. Both analytical and actual experimental results show that batch forwarding significantly improves the efficiency and delivery radio, particularly in heavily loaded network environments. Despite some delay due to batch formation, batch forwarding also improves the overall end2end delay performance due to its efficient use of resources. As a result, batch forwarding is a viable data gathering solution and should be used in WSN applications that generate significant amount of sensing data and require high delivery ratio and less delay.