Energy Efficient Protocol for Wireless Sensor Network

Wireless sensor network (WSN) has emerged as one of the most promising technologies for the future. Several applications including military surveillance, scientific exploration, disaster prevention and monitoring, healthcare have been envisioned for them. The unique features of wireless sensor network give rise to new challenges in communication protocol, hardware and application design. Since nodes have limited energy supply, they are operated on low-duty-cycle. Nodes stay awake for a very small time between two long dormant periods. Low-duty-cycle flooding is a challenging problem for wireless sensor networks as every node has a random working schedule. Existing traditional flooding methods for always-awake networks cannot be used directly for wireless sensor networks. Opportunistic flooding is state-of-the-art flooding protocol for low-duty-cycle flooding in wireless sensor networks with asynchronous working schedule. In this work, three different protocols namely protocol X, protocol Y and protocol Z have been proposed for flooding in low-duty-cycle wireless sensor networks. Their performance is compared with opportunistic flooding protocol and the optimal bounds. It is observed that protocol Z outperforms all other protocols. Effects of link-quality variations and node failures on the performance of the protocol Z are investigated. It is shown that link-quality variations as high as 20% have insignificant impact on flooding performance. To ensure high flooding coverage in the presence of node failures, modified protocol Z is proposed. Modified protocol Z ensures high flooding coverage while incurring a little more energy cost than protocol Z.