Effects of RPL objective functions on the primitive characteristics of mobile and static IoT infrastructures

Abstract

The emergence of mobile IoT applications in recent years and the challenge of routing in their infrastructures have motivated scholars to propose appropriate routing mechanisms for such systems. Meanwhile, the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL) is the standard routing protocol for IoT infrastructures. Nevertheless, RPL was mainly designed to comply with the primitive requirements of static IoT applications and it behaves poorly in confronting with the severe alterations in mobile conditions. The most important factor for such a poor behavior in mobile applications is the inappropriate design of OFs, which determine RPL’s routing policies in the network. Therefore, the functionality and efficiency of the existing OFs should be carefully studied in order to determine their downsides and to resolve them in the future OF designs. Accordingly, in this paper, due to lack of information on how OFs affect the primary requirements of IoT infrastructures in mobile and static infrastructures, we have compared and evaluated the effect of state of the art OFs on the functionality of the nodes and the network from different perspectives. Our evaluations on fixed-node IoT infrastructures have shown that OFs could affect the power consumption by up to 80%, while their impact on reliability and E2E delay would be as high as 54% and 75%, respectively. Further observations have proven that mobility would reduce OFs contribution in power consumption by more than 10% in comparison with static IoT infrastructures, while it can increase their influence on reliability and E2E delay by nearly 15% and 16%, respectively.