FTC-OF: Forwarding Traffic Consciousness Objective Function for RPL Routing Protocol

Abstract

The diversity of Internet of Things applications require a flexible routing protocol to cope with several constraints. In this context, the RPL protocol was designed to meet the needs of IoT. RPL relies on an objective function based on specific metrics to fulfill its routing strategy. The single routing metric problem leads generally to non-optimized routes selection. As a consequence, two major issues emerge, mainly the node’s congestion due to the high number of forwarded packets, also the greedy energy consumption by those nodes that conduct to fast batteries draining. In that purpose, Forwarding Traffic Consciousness Objective Function has been proposed, which combines three routing metrics, namely hop count, RSSI and a newly designed Forwarded Traffic Metric (FTM). The proposed method, evaluated using COOJA against ETX and Energy based RPL, showed a packet delivery ratio increase respectively with 2% and 11% in low and high traffics, considerably reduces the power consumption with approximately 47% as well as it achieves a good balance of traffic managed by the relay nodes.