Elastic resource utilization framework for high capacity and energy efficiency in cloud RAN

Current radio access network architectures, characterized by a static configuration and deployment of base stations, have exposed their limitations in handling the temporal and geographical fluctuations of capacity demand. Moreover, small cell networks have exacerbated the problem of electromagnetic interference and decreased the energy efficiency. Although there are some solutions to alleviate these problems, they still suffer from static provisioning of BSs and lack of inter-BS communication. Cloud RAN is a new centralized paradigm based on virtualization technology that has emerged as a promising architecture and efficiently addresses such problems. C-RAN provides high energy efficiency together with gigabit-per-second data rates across software defined wireless networks. In this article, novel reconfigurable solutions based on C-RAN are proposed in order to adapt dynamically and efficiently to the fluctuations in per-user capacity demand. Co-location models for provisioning and allocation of virtual base stations are introduced, and pros and cons of different VBS architectures are studied. Also, the potential advantages of VBS clustering and consolidation to support recently proposed cooperative techniques like cooperative multipoint processing are discussed.

Introduction

Over the last few years, the proliferation of personal mobile computing devices like tablets and smartphones, along with a plethora of data-in-tensive mobile applications, has resulted in a tremendous increase in demand for ubiquitous and high data rate wireless communications. The current practice to enhance data rate is to increase the number of base stations (BSs) and go for smaller cells to increase the band reuse factor. However, additional deployment and maintenance of a large number of BSs bring high inefficiencies due to excessive capital and operating expenditures. It has also been found that increasing the BS density or the number of transmit antennae will decrease energy efficiency (EE) due to the exacerbation of the electromagnetic interference problem and of the cooling requirements of cell site equipment [1].