On Outage of Wireless Cloud Computing: Offloading Optimization and Bottleneck Analysis

Wireless cloud computing system with computation offloading has attracted much attention due to the potential of alleviating the restrictions of limited resources in mobile devices. During the computation offloading, the steps of transmissions and computation need to be completed within the required time, otherwise the system will be in outage. Due to uncertainties of channel fading and computational complexities, such outage is the result of either transmission outage or computation outage. In this paper, a theoretical framework is proposed to analyze the outage of the wireless cloud computing system with multiple subcarriers and computation resources. Through theoretical analysis of the outage probability, the outage bottleneck can be identified. Numerical results have verified the theoretical analysis and concluded that the outage bottleneck depends not only on the distributions of complexities of tasks but also on the numbers of subcarriers and computation resources.