RELAX: An Energy Efficient Multipath Routing Protocol for Wireless Sensor Networks

This paper presents an energy efficient multipath routing protocol specifically designed for wireless sensor networks (referred as RELAX). RELAX protocol tries to utilize the relaxation phenomenon of certain batteries to increase the battery lifetime and hence increasing the overall lifetime of the sensor network. Relaxation periods enable the battery to recover a portion of its lost power; it has been proven that the intermittent operation of some alkaline batteries increases its lifespan by about 28%. RELAX uses a link cost function that depends on current residual energy, available buffer size, and link quality (in terms of Signal-to-Noise ratio) to predict the best next hop during the path construction phase. RELAX routes data across multiple paths to balance the energy consumed across multiple nodes and to increase the throughput as well as minimizing packet end-to-end delay. Before transmitting the data, RELAX protocol adds data redundancy through a light weight Forward Error Correction (FEC) technique to increase the protocol reliability and resiliency to path failures. Many simulation experiments have been cried out to evaluate the protocol performance. Results show that RELAX protocol achieves lower energy consumption, lower packet delay, higher throughput, and long node lifetime duration compared to other protocols.