Joint routing and mobile VM selection algorithm in multihop C-RAN networks.

By combining the cloud radio access network (C-RAN) and mobile cloud computing, the communication and computation cooperation is convenient to implement, and the mobile operators are able to provide better service for mobile users as well as decrease their construction funds. However, owing to the deficient bandwidths and far distances, some mobile devices are not able to access mobile cloud through C-RAN directly. In this paper, we propose a multihop C-RAN network to access mobile cloud that organizes the user equipment (UE) in the C-RAN into self-organized network, regarding UEs as relay routers to access the mobile cloud. Under the proposed architecture, the UEs far from remote radio heads are able to access C-RAN by ad hoc network while the UEs near the remote radio heads will access C-RAN directly. Besides, considering the benefit of both operators and mobile users, we propose a joint routing and mobile virtual machine (VM) selection algorithm based on the proposed multihop C-RAN networks where the route is selected for task data transmission, and the VM in the mobile cloud is selected for task execution, which minimizes the total energy cost under the premise of satisfying the task response time required by user. The simulation result shows that the proposed algorithm outperforms conventional separate routing and VM selection on energy saving.