REFER: A Reliable and Energy-Efficient RPL for Mobile IoT Applications

Recently, IoT has been massively applied in different areas of human life. Meanwhile, in many of the IoT applications, e.g., the remote patient health-care monitoring systems, the reliability of communications, and the consumed energy in IoT devices, which are mostly battery-operated, are very challenging. Since IoT devices are typically operated in lossy environments, providing a reliable transmission for the packets imposes a noticeable amount of energy consumption. In addition, the runtime movement of the IoT devices in mobile networks further intensifies these issues. Therefore, the applied policies in the IPv6 RPL as the standard routing mechanism in IoT networks, play an important role in providing a reliable and energy-efficient packet delivery. Nevertheless, RPL is significantly suffering from low reliability in mobile applications due to existence of outdated parents in the limited neighbor table of the moving objects. Hence, in this study, we propose REFER; a mobility-aware version of RPL, which provides reliable and energy-efficient communication between IoT devices with utilizing a new neighbor placement policy based on a leasing time of the parents along with considering various node/link metrics for its path selections in mobile situations. Based on our evaluations, which have been conducted in different network configurations and under different mobility models, while REFER has enhanced the amount of energy consumption in the nodes, it is able to improve the reliability of the communications by at least 2.2x compared with its counterpart.