Enhancing RAN throughput by optimizec controller placement in optical metro networks

For the incoming 5G mobile communications, enhanced cell coordination is deemed as crucial to maximize network throughput. In this paper we focus on the impact that the placement of coordination controllers in the metro optical network has on the performance of cell coordination, and we aim at verifying how throughput maximization can be achieved through optimized controller placement. Specifically, we refer to Coordinated Multipoint (CoMP), a protocol that allows to coordinate cell clusters through a Radio Controller Coordinator (RCC) to enhance the mobile-network throughput by reducing interference. Several CoMP techniques have been designed, whose throughput gain is affected differently by various factors. E.g., gains increases with the size of the cluster, while it decreases for larger latencies between RCC and cells. Current metro/aggregation networks are characterized by a hierarchical architecture with different levels of central offices, so the decision of where to place RCC in order to maximize CoMP throughput gain is not trivial and depends on several factors, such as geographical dimension of the network, cluster size and latency experienced before reaching the RCC. Our results show that under certain conditions optimized placement provides benefits with respect to fixed placement of controllers