I. Introduction
Mobile user equipment (UEs), such as smartphones and laptops, are proliferating with the technological evolutions. More and more computation-intensive applications are being rapidly applied on those UEs. Despite the increase of the computing capacity of the UEs, the UEs cannot deal with the tasks that need a lot of computational resources with a large amount of battery energy in a short period [1]. Mobile cloud computing (MCC), which can provide powerful computing and storage resources for UEs to complete computation tasks, is a paradigm to handle the energy-intensive computational tasks [2]. By offloading energy-intensive computational tasks to mobile clouds, MCC can provide UEs with cloud computing services, reduce battery consumption of UEs, and improve user experience. However, if the MCC servers are far away from UEs, they may not be able to satisfy the delay requirement of users.