Lyapunov Optimization Based Trade-Off Policy for Mobile Cloud Offloading in Heterogeneous Wireless Networks

In order to improve life mobile users' service experience, mobile cloud computing (MCC) is promoted, which can offload these compute-intensive applications to cloud. Although MCC can alleviate the burdens of Smart mobile devices (SMDs), it also aggravates the computing and storage overheads in cloud center and bandwidth overhead on wireless links for applications offloading. Therefore, we should carefully design the offloading policy to decrease these overheads while easing the burdens of SMDs. To this end, we investigate the offloading policy in heterogeneous wireless networks. In this paper, a queue is built to formulate the mobile users' workload offloading problem and Lyapunov optimization is used to make trade-off between the system offloading utility and the queue backlog. First, based on the deterministic WiFi connection, a Lagrangian optimization method is proposed to decide the optimal offloading workloads. Furthermore, considering the random WiFi connection durations, a multi-stage stochastic programming is adopted. The experimental results show the effectiveness of the Lagrangian optimization offloading method for deterministic WiFi connection and the multi-stage stochastic programming method for random WiFi connection.