Profit-Based Algorithm of Joint Real-Time Task Scheduling and Resource Allocation in C-RANs

In cloud radio access networks (C-RANs), a local controller controls a set of lightweight remote radio heads (RRHs) for connecting users nearby, and creates virtual machines (VMs) for executing user tasks. In view of previous works, the strategies of minimizing system resource consumption or transmission delay are adopted in the issue of joint task scheduling and resource allocation. Different from them, this work puts forward the strategy of maximizing the profit of the joint issue. The problem is formulated as integer linear programming (ILP), and then an algorithm with bounded approximation ratio for solving the ILP is proposed. The simulation results show that the solution of the algorithm is very close to the optimal one of the ILP. In addition, another algorithm is proposed to control the tradeoff between performance and robustness of the solution under the assumption that the system resource can be expanded by a bounded factor.