부산대학교 도서관

The routing protocol for low-power and lossy networks(RPL) is an internet protocol based routing protocol developed andstandardized by IETF in 2012 to support a wide range of applicationsfor low-power and lossy-networks (LLNs). In LLNs consistingof resource-constrained devices, the energy consumption ofbattery powered sensing devices during network operations cangreatly impact network lifetime. In the case of inefficient route selection,the energy depletion from even a few nodes in the networkcan damage network integrity and reliability by creating holes inthe network. In this paper, a composite energy-aware node metric(RERBDI ) is proposed for RPL; thismetric uses both the residualenergy ratio (RER) of the nodes and their battery discharge index. This composite metric helps avoid overburdening power depletednetwork nodes during packet routing from the source towards thedestination oriented directed acyclic graph root node. Additionally,an objective function is defined for RPL, which combines the nodemetric RERBDI and the expected transmission count (ETX) linkquality metric; this helps to improve the overall network packetdelivery ratio. The COOJA simulator is used to evaluate the performanceof the proposed scheme. The simulations show encouragingresults for the proposed scheme in terms of network lifetime,packet delivery ratio and energy consumption, when compared tothe most popular schemes for RPL like ETX, hop-count and RER.