A hybrid heuristic queue based algorithm for task assignment in mobile cloud

This paper presents a novel algorithm for task assignment in mobile cloud computing environments in order to reduce offload duration time while balancing the cloudlets' loads. The algorithm is proposed for a two-level mobile cloud architecture, including public cloud and cloudlets. The algorithm models each cloud and cloudlet as a queue to consider cloudlets' limited resources and study response time more accurately. Performance factors and resource limitations of cloudlets such as waiting time for clients in cloudlets can be determined using queue models. We propose a hybrid genetic algorithm (GA) - Ant Colony Optimization (ACO) algorithm to minimize mean completion time of offloaded tasks for the whole system. Simulation results confirm that the proposed hybrid heuristic algorithm has significant improvements in terms of decreasing mean completion time, total energy consumption of the mobile devices, number of dropped tasks over Queue based Random, Queue based Round Robin and Queue based weighted Round Robin assignment algorithms. Also, to prove the superiority of our queue based algorithm, it is compared with a dynamic application scheduling algorithm, HACAS, which has not considered queue in cloudlets.