Service-Differentiated Cooperative Routing in the Internet of Things
von Milad Ayoub
Datum der mündl. Prüfung:2023-03-03
Betreuer:Prof. Dr. Dieter Hogrefe
Gutachter:Prof. Dr. Dieter Hogrefe
Gutachter:Prof. Dr. Xiaoming Fu
EnglischThe IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) was designed to operate with different Internet of Things (IoT) applications ranging from regular, to critical, to alarm/sporadic. That is due to its ability to support service differentiation by forwarding multiple traffic classes via different logical network subdivisions called instances. Cooperation among multiple instances running multiple applications can help in mitigating congestion, which is the main factor degrading the Quality of Service in multi-application environments such as the Smart Grid. Available solutions for cooperation between two or more RPL instances are centralized and reactive. The problem with the centralized approach is that it requires control messages to flow in both directions in the network (from the leaf nodes to the root and back), which increases overhead and energy consumption. Reactive solutions force cooperating nodes to send cooperation requests to the root and wait for cooperation confirmation messages. In heavy traffic scenarios, which increase the probability of path congestion, the reliability of such message exchanges cannot be guaranteed. Furthermore, these proposed centralized and reactive models do not address the issue of congestion and were not evaluated under heavy traffic. We design a novel IPv6 routing protocol, based on RPL, for low-power and lossy IoT networks that support service differentiation. Our protocol enables distributed and proactive cooperation among its instances for congestion control. In our model, congestion detection is performed using a novel routing metric that locally estimates the path’s congestion level under heavy and dynamic traffic. Our protocol utilizes the path diversity offered by other instances to mitigate congestion. It also employs a novel, distributed, proactive cooperation management scheme to tackle the issue of selfishness among cooperating nodes. We evaluate our protocol in a Smart Grid system where multiple alarm and monitoring applications coexist. We also propose a framework for cooperation among instances that belong to different authorities. Our proposed framework targets scenarios where one instance's root is located close to some leaf nodes of another instance and vice versa. By exploiting the available backbone infrastructure, we design a scheme for cooperation encouragement between Smart City subsystems based on a virtual currency exchange model.
Keywords: Internet of Things; Routing; RPL; Low-power and Lossy Networks; Smart Grid; Smart City; Congestion control