Impact of CoMP VNF placement on 5G Coordinated Scheduling performance

To address demanding requirements in terms of expected throughput, latency and scalability, 5G networks will offer high capacity to support huge volumes of traffic generated by heterogeneous services. Dense deployment of small cells can provide a valid solution but are prone to high levels of interference especially at the cell-edge. However, to reduce inter-cell interference and improve cell-edge throughput, a set of techniques known as Coordinated Multipoint (CoMP) has been introduced. Coordinated Scheduling (CS) is a CoMP technique that assigns resources to mobile users to avoid interference between users that are assigned within the same Physical Resource Blocks (PRBs). On the other hand, Software Defined Mobile Networking (SDMN) and Network Function Virtualization (NFV) represent two key technologies to enhance flexibility and efficiency of resource usage within the Radio Access Network (RAN). However, the implementation of CoMP CS techniques on NFV architecture in a dense small cell scenario have not been analyzed yet. In this paper, we propose the joint use of CoMP CS and NFV by studying the implications of different deployment strategies, as constrained by the physical topology of the underlying RAN. The performance of both distributed and centralized CoMP CS are compared in terms of convergence delay and traffic overhead. Guidelines for the optimal design are provided.