On the throughput-energy tradeoff for data transmission between cloud and mobile devices

Mobile cloud computing has recently emerged as a new computing paradigm promising to improve the capabilities of resource-constrained mobile devices. As the data processing and storage are moved from mobile devices to powerful cloud platforms, data transmission has become an important issue affecting user experiences of mobile applications. One of the challenges is how to optimize the tradeoff between system throughput and energy consumption, which are potentially conflicting objectives. Inspired by the feasibility of transmission scheduling for prefetching-friendly or delay-tolerant applications, we mathematically formulate this problem as a stochastic optimization problem, and design an online control algorithm to balance such an energy-performance tradeoff based on the Lyapunov optimization framework. Our algorithm is able to independently and simultaneously make control decisions on admission and transmission to maximize a joint utility of the average application throughput and energy cost, without requiring any statistical information of traffic arrivals and link bandwidth. Rigorous analysis and extensive simulations have demonstrated both the system stability and the utility optimality achieved by our control algorithm.