IMPROVED ROUTING PROTOCOLS BASED ON RPL FOR FULL IOT-WSN STACK
Keywords:Routing protocols, Wireless sensor networks, Internet of Things, RPL, CoAP, Objective function, Cooja.
The Internet Engineering Task Force (IETF) standardized several protocols such as Constraint Application Protocol (CoAP) to run over WSN-IoT constrained devices. IPv6 is used to transmit packets over IEEE802.15.4 radio link called 6LoWPAN. The routing protocol for low power and lossy (RPL) network enable connectivity of WSN over IoT. Nodes in RPL optimized its path using objective function (OF), which depends on different node/link metrics. In this paper, the performance of IoT-WSN stack consisting of CoAP, 6LoWPAN and two proposed protocols based on RPL are evaluated. The two proposed protocols depend on a new OF based on link reliability and energy metric. The first is a modification of recently introduced protocol called Energy Threshold RPL (ETRPL) protocol. ETRPL uses the remaining energy of the preferred parent node as a metric. The other protocol used a new metric that combines energy consumption with ETX for all paths to the root called EERPL. The protocols are tested with full IoT-WSN stack and implemented using Cooja simulator. The results showed that ETRPL and EERPL performed better than standard RPL in terms of the energy consumption, average time delay, packet reception ratio, throughput and the number of dead nodes.