Advances in CRAN Performance Optimization

The exponential growth of cellular data traffic over the years imposes a hard challenge on the next cellular generations. The cloud radio access network is an emerging cellular architecture that is expected to face that challenge effectively. The main difference between the CRAN architecture and the conventional cellular architecture is that the baseband units (BBUs) are aggregated at a centralized BBU pool, hence, enabling statistical multiplexing gains. However, to acquire the several advantages induced from the CRAN architecture, efficient optimization algorithms should be used to enhance the network performance. In this article, we give an overview of cloud radio access networks, highlighting the advantages of its architecture over conventional cellular networks. Then we illustrate the performance metrics that should be considered for optimization in CRAN, and the important parameters to optimize. We review some of the recent research works in CRAN performance optimization. We highlight the current challenges faced in CRAN performance optimization and discuss open issues.