IP-RPL: A Protocol for Efficient Point-to-Point Communication in Low Power and Lossy Networks

The Internet of Things (IoT) has become a reality, and with it a host of challenges for fulfilling its potential. Being a key IoT-enabling technology, the Low Power and Lossy Network (LLN) has a decisive role in the future of the IoT paradigm. The LLN routing protocols, including the IPv6 Routing Protocol for LLNs (RPL), lack efficiency in handling point-to-point communications. Considering the rapidly changing Internet scenario in which point-to-point communications have a share of approximately half of the total traffic, the need to address the concerns of point-to-point routing in LLNs is increasingly experienced than ever before. In this paper, we present an Improved P2P RPL (IP-RPL) that efficiently handles the point-to-point traffic in LLNs. The proposed protocol constructs up to four point-to-point source routes, satisfying the constraints given by the higher layers, on-demand towards the destination(s). IP-RPL mitigates the control overhead and latency associated with frequent point-to-point route discoveries through a well-defined route caching technique. The simulation results indicate a better performance for IP-RPL compared to its existing counterparts in terms of packet delivery ratio, average power consumption of nodes, packet overhead, and end-to-end delay.