Cloud Radio Access Networks

Abstract

Radio virtualization and cloud signal processing are new approaches to building cellular Radio Access Networks (RAN) that are starting to be deployed within the cellular industry. For cellular operators, Cloud RAN architectures that centrally define or decode transmissions, placing most of the base-station software stack within a data-centre, promise improvements in flexibility and performance. The expected benefits range from standard cloud economies—statistical reductions in total processing, energy efficiency, cost reductions, simplified maintenance—to dramatic changes in the functionality of the radio network, such as simplified network sharing, capacity increases towards theoretical limits, and software defined radio inspired air interface flexibility. Because cellular networks have, in addition to complex protocols, extremely sensitive timing constraints and often high data-rates, the design challenges are formidable. This chapter presents the state of the art, hybrid alternatives, and directions for making Cloud Radio Access Networks more widely deployable.