Energy-Efficient Routing in Low Power and Lossy Networks Under Hybrid Mode RPL

The Internet of Things (IoT) has become a reality. With the rapid proliferation of newer IP-enabled devices, IoT-enabling technologies need upgrading to meet the demands of the current Internet scenario. Low Power and Lossy Network (LLN) is one such IoT-enabling technology that directly impacts the performance of various IoT applications. Hence, the IPv6 Routing Protocol for LLNs (RPL) is important in ensuring seamless connectivity among IoT devices. Even though the existing literature comprises several RPL enhancements addressing important issues, the mixing of two operational modes, i.e., the storing mode and the non-storing mode, in the same LLN is still in the nascent stage. Also, the impact of such hybrid mode RPL on different Objective Functions (OFs) needs more exploration. Considering the relevance of the two operational modes on popular IoT applications like smart homes that involve device-to-device communications, this research work presents the impact of hybrid mode RPL on a novel energy-efficient OF. The OF includes a novel metric named Packet Energy Ratio (PER) that considers both residual energy and queue length of nodes to perform preferred parent selection. The experimental results underline the positive impact a hybrid mode RPL can have on the OF, compared to that of storing and non-storing modes. The performance comparisons consider metrics like packet delivery ratio, average power consumption of nodes, packet overhead, and end-to-end delay.