Joint Energy-QoE Efficient Content Delivery Networks Using Real-Time Energy Management

In this paper, a joint optimization method has been proposed for energy cost and the user's perceived quality-of-experience (QoE) within a content delivery network (CDN). The proposed algorithm has been developed with an objective to minimize the total operational cost using real-time electricity pricing as well as the integration of green energy resources from the smart grid. To solve the joint optimization problem, a linear programming and a differential evolution algorithm have been used to provide a tradeoff between operational cost saving and computational complexity. We also formulate the joint problem as a noncooperative game in which the CDN providers act as players. A group utility function has been defined for the players and it is shown that a Nash equilibrium exists for the joint quality and energy cost saving when each CDN provider has single cluster or multiple clusters. Numerical results are presented to evaluate and validate the aforementioned solutions. These results illustrate significant operational/energy cost reductions while optimizing user's perceived QoE for a CDN or multiple CDN providers with respect to conventional methods.