Efficient Downward Routing in IoT Networks: A Novel Leaf-Centric Mode for RPL

RPL, the standard routing protocol for low-power and lossy networks, offers two modes for handling downward traffic: storing and non-storing. Each has significant limitations - the storing mode struggles with router memory constraints, potentially making destinations unreachable when a router's storage capacity is reached. Conversely, the non-storing mode mitigates this issue by employing source routing, but at the expense of increased network overhead. To address these challenges, this paper introduces the Leaf-Centric Mode (LCM), a novel approach that dramatically reduces storage requirements by enabling nodes to maintain routing information only for leaf nodes within their sub-networks, rather than all nodes. This optimized approach offers key advantages for IoT applications, including reduced storage footprint, improved reliability, lower network overhead, and enhanced overall performance. Through comprehensive experimental evaluation, we demonstrate the practical effectiveness of the LCM and establish its viability for IoT applications.