Delay and Power Tradeoff With Consideration of Caching Capabilities in Dense Wireless Networks
Hao Wu, Hancheng Lu · IEEE Transactions on Wireless Communications · 2019
Enabling caching capabilities in dense small-cell networks (DSCNs) has a direct impact on file delivery delay and power consumption. Most of the existing works studied these two performance metrics separately in cache-enabled DSCNs. However, file delivery delay and power consumption are coupled with each other and cannot be minimized simultaneously. In this paper, we investigate the optimal tradeoff between these two performance metrics. First, we formulate the joint file delivery delay and power consumption optimization (JDPO) problem where power control, user association, and file placement are jointly considered. Then, we convert it into a form that can be handled by the generalized Benders decomposition (GBD). With GBD, we decompose the converted JDPO problem into two smaller problems, i.e., the primal problem related to power control and the master problem related to user association and file placement. An iterative algorithm is proposed and proved to be an $\epsilon $ -optimal, in which the primal problem and the master problem are solved iteratively to approach the optimal solution. To further reduce the complexity of the master problem, an accelerated algorithm based on semi-definite relaxation is proposed. Finally, the simulation results demonstrate that the proposed algorithm can approach the optimal tradeoff between file delivery delay and power consumption.