Dynamic virtual network connectivity services to support C-RAN backhauling

Traditional distributed radio access networks (RANs) are evolving toward centralized architectures, with the aim of satisfying in a cost-effective manner the forecast traffic growth that future mobile networks will need to support. Specifically, the cloud RAN (C-RAN) architecture has shown that it can alleviate to some extent the everincreasing total cost of ownership in mobile networks. The current trend in C-RAN is to separate remote radio heads with radio frequency (RF) functions and baseband unit (BBU) gathering baseband processing. This functional split allows the RF modules to be kept close to the antennas while placing BBUs at centralized locations so they can be shared among different sites and even be virtualized. However, some issues still need to be addressed in future mobile networks, especially due to the dynamicity of services and the strict constraints imposed by the interfaces needed. In fact, connectivity reconfiguration for X2 and S1 backhaul interfaces needs to be provided as an all-or-nothing request to enable mobile resource reconfiguration in a geographical area. In view of this, in this paper we propose dynamic customer virtual network (CVN) reconfiguration to be supported in metro and core network segments. Such CVN requests must include quality of service constraints to ensure specific delay constraints, as well as bitrate guarantees to avoid service interruption. A mathematical formulation and heuristic algorithm are presented for the CVN reconfiguration problem, and exhaustive simulation results study its performance in realistic scenarios.