DYNAMIC TASK OFFLOADING FOR LATENCY MINIMIZATION IN IOT EDGE-CLOUD ENVIRONMENTS
With the exponential growth and diversity of Internet of Things (IoT) devices, computational-intensive and delay-sensitive applications, such as object detection, smart homes, and smart grids, are emerging constantly. We can adopt the paradigm of cloud computing to offload computation-heavy tasks from IoT devices to a cloud server which can break through the limitation of IoT devices with more powerful resources. However, cloud computing architecture can cause high latency which is not suitable for IoT devices that have limited computing and storage capabilities. Edge computing has been introduced to improve this situation by deploying an edge device nearby IoT devices that can provide IoT devices computing resources with low latency compared to cloud computing. Nevertheless, the edge server may not be able to complete all the offloaded tasks from the devices in time when the requests are flooding. In such cases, the edge server can offload some of the requested tasks to a cloud server to further speed up the offloading process with more powerful cloud resources. In this paper, we aim to minimize the average completion time of tasks in an IoT edge-cloud environment, by optimizing the task offloading ratio from edge to cloud, based on Deep Deterministic Policy Gradient (DDPG), a type of Reinforcement Learning (RL) approach. We propose a dynamic task offloading decision mechanism deployed on the edge that can determine the amounts of computational resources to be processed in the cloud server considering multiple factors to complete a task. Simulation results demonstrate that our dynamic task offloading decision mechanism can improve the overall completion time of tasks than naïve approaches.