RAID the WSN: Packet-based reliable cooperative diversity

This paper introduces a light-weight packet delivery approach called Packet-based Cooperative Diversity to improve the reliability of Wireless Sensor Networks (WSNs). Our approach is based on the principle of cooperative diversity and fail-over concepts of Redundant Array of Independent Disks (RAID), by grouping, gathering, and rejecting redundant packets with the unique packet ID per message. It is suitable for nodes which require high reliability in message delivery but have enhanced energy capability. Our approach imitates two RAID levels to investigate their effect in reliability by redundancy. Based on an analytical model and ns-2 simulations, we compare the performance of our packet-based diversity schemes with direct transmission. Our schemes improve the reliability significantly in terms of the Improved Message Reconstruction Ratio per Redundancy (MRR/R) about 25% in the analytical model and 15% in simulation. The results indicate that our approach is especially effective in situations with strong interferences.