Joint Energy Minimization and Resource Allocation in C-RAN with Mobile Cloud

Cloud radio access network (C-RAN) has emerged as a potential candidate of the next generation access network technology to address the increasing mobile traffic, while mobile cloud computing (MCC) offers a prospective solution to the resource-limited mobile user in executing computation intensive tasks. Taking full advantages of above two cloud-based techniques, C-RAN with MCC are presented in this paper to enhance both performance and energy efficiencies. In particular, this paper studies the joint energy minimization and resource allocation in C-RAN with MCC under the time constraints of the given tasks. We first review the energy and time model of the computation and communication. Then, we formulate the joint energy minimization into a non-convex optimization with the constraints of task executing time, transmitting power, computation capacity and fronthaul data rates. This non-convex optimization is then reformulated into an equivalent convex problem based on weighted minimum mean square error (WMMSE). The iterative algorithm is finally given to deal with the joint resource allocation in C-RAN with mobile cloud. Simulation results confirm that the proposed energy minimization and resource allocation solution can improve the system performance and save energy.

1 Introduction

Nowadays, the number of the smart devices and the corresponding mobile traffic have grown rapidly, which poses an increasingly high burden on the existing cellular network. It is predicted that the mobile device traffic will increase 1,000 times and the cost is expected to decrease one hundred times by 2020, with the help of new network and computation paradigm [1]. Moreover, more and more computational resource intensive tasks, such as multimedia applications, high definition video playing and gaming appear in our daily life, make the load of both the mobile phone and the network, in terms of energy and bandwidth, increase hugely. Further, those types of applications have the trend of attracting more and more attention from the smartphone users.