Impact of Path Metrics on RPL's Performance in Low Power and Lossy Networks

Recent years witness immense growth in the Internet of Things (IoT) based applications ranging from healthcare sector to agriculture sector due to 6LoWPAN enabled sensor radios. Routing of data packets in the sensor (or) low power and lossy network (LLN) environment always remains a challenge due to sensor node's inherent limitations such as tiny memory, limited processing capability, and limited battery energy. To meet the specific routing requirement in harsh environments, IETF standardized IPV6 based routing protocol for low power and lossy networks (RPL) intended to support 6LoWPAN enabled sensor radios for large-scale deployment. RPL selects the best path based on objective function (OF) or path metrics. The strength of the RPL depends on choosing of best OF, which creates an optimum path between a source and sink nodes. In this paper, simulation and analysis of RPL protocol carried out with two different internal objective functions (hop length and link quality) using Cooja Simulator. The performance of the OF is measured based on following metrics such as throughput, end-to-end latency, packet drop, energy and loss ratio. This analysis paves the way for developing an improved version of RPL with apt OFs that withstand both in static and mobile wireless conditions.