Energy balancing RPL protocol with multipath for wireless sensor networks

With the rising trend of the incidence and prevalence of chronic diseases all over the world, proactive healthcare systems with wireless sensor network (WSN) technology have attracted people’s extensive attention. One of the researches, such as routing protocol for low power and lossy networks (RPL) only takes into consideration a single metric, energy, hops or routing quality, and so on. To extend the survival time of the network effectively and maximize the utilization of energy, we need to consider both node metric and link metric that affect the network, and design IRPL (Improved RPL) protocol. We propose the life cycle index (LCI) as path selection objective function. The index takes node metric (node energy and node hops) and link metric (throughput, packet loss, link quality) into consideration. In order to detect and distribute congestion information, we add congestion detection factor to the index. According to node energy, hop and congestion detection factor, we optimize the calculation method of rank. Our method redesigns parent node selection strategy. Not only does the strategy select the best parent node by using the improved index, but also saves other parent nodes that meet the conditions. Meanwhile, we propose a multipath scheme by using the DODAG structure, and use the scheme to solve the congestion problem. The simulation results show that the scheme shows better performance in terms of network load, end-to-end delay, packet delivery ratio, percentage of the optimal parent node change, energy consumption and network lifetime.