QoE Aware IoT Application Placement in Fog Computing Using Modified-TOPSIS

Over the years, fog computing has emerged as a paradigm to complement the cloud computing in handling the delay sensitive IoT applications in a better manner. Using fog resources, better performance such as in-time service delivery, reduced network load, optimal energy usage etc. can be achieved. With such performance gain, users availing the IoT services are more satisfied. A well-known metric Quality of Experience (QoE), used to measure the satisfaction of IoT users, can be improved by enhancing the performance of the IoT applications. Fog computing is a geographically distributed paradigm and primary service of fog computing may not include the execution of offloaded tasks/applications from the IoT devices. This makes QoE aware placement of applications in fog computing a greater challenge. Since placement algorithm is itself a computational task and both IoT applications and fog nodes need a mediator fog node to execute the placement algorithm, the placement policy should be light weighted in terms of computational complexity. This work proposes a lightweight QoE aware application placement policy in fog computing using Modified TOPSIS that prioritizes the applications and fog instances based on their expectation and computational capability respectively for the placement. Modified TOPSIS inherits all the features of classical TOPSIS while it removes rank reversal problem of classical TOPSIS. Simulation experiments, for a comparative study, depict that the proposed model not only achieves the desired resource utilization, processing time, and reduced network congestion but reduces the application placement time also significantly compared to the state of art.