Multiple RPL Objective Functions for Heterogeneous IoT Networks

Abstract

RPL (Routing Protocol for low power and lossy networks) is an IETF standardized and widely used routing protocol for low-power lossy networks. It selects routes based on an objective function that defines the routing metrics and constraints (if any). The standard specifies multiple routing metrics like expected transmission count (ETX), latency, hop-count, remaining power in the device, etc. to select routes, but none of these metrics singularly are suited for heterogeneous networks. In a power constrained network, several factors effect the quality of service (QoS) and therefore to achieve an optimal routing solution, combination of several metrics is to be considered based on the network. Hence, in this paper multiple objective functions are designed considering the a constrained network with heterogeneous nature, similar to that of a smart grid during both low and high traffic load. The multi-objective metrics consider energy, link quality, delay, and hop-count as parameters to compute the metrics. Simulations show that the proposed multi-objective function(s) increase network lifetime, throughput, and also lowers the packet loss in the network.