Abstract
With the rapid development of novel techniques like software-defined networks and network function virtualization, the newer concept-service function chains (SFCs)-can be applied in the Internet of Things (IoT) to promote its further advancements. However, due to the unique characteristics and requirements of the IoT, the current optimization methods cannot be directly used to implement IoT service function chains (IoTSFCs). In this paper, we present a novel orchestration scheme to resolve this problem. It contains two steps: compose and place IoTSFCs. In the composition stage, a multicriterion-based arrangement algorithm is designed to determine the order of involved IoT network functions. Moreover, we modify a traditional SFC definition language to describe the composed IoTSFCs. In the placement stage, we formulate this subproblem as a mixed-integer linear programming model. Then, a genetic-algorithm-based heuristic method and a tradeoff mechanism are used to solve it. Finally, we conduct extensive numerical simulations to evaluate the performance of the proposed scheme. The results show that it can approximately reduce the control latency by 50% and the bandwidth consumption by 40% on average.