Resiliency in Open-Source Solutions for Disaggregated 5G Cloud Radio Access and Transport Networks

Cloud Radio Access Network (C-RAN) has emerged as an advantageous architecture to address the needs of future wireless networks. Leveraging both Network Functions Virtualization and Software-Defined Networking (NFV-SDN) technologies, the C-RAN components can be disaggregated and potentially run in a virtualized environment where either virtual machines (VMs) or containers are efficiently applied. C-RAN solutions require highly reliable fronthaul, midhaul, and backhaul network designs. This work first describes a programmable optical software-defined network testbed that offers fronthaul, midhaul, and backhaul transport capabilities supporting C-RAN functionalities with increased reliability. Optical transport programmable (SDN) capabilities also facilitate live-migration of C-RAN functions between sites in order to achieve improved compute load-balancing and fault-tolerance of the overall C-RAN system. Container-based frameworks are increasing gaining momentum due to their smaller footprint size compared to VM's. However, the extant container migration software frameworks do not support mobile network protocol stacks. The second contribution of our work focuses on the live-migration of both containerized core network and RAN central unit virtual functions, which is achieved through a proof-of-concept implementation based on open-source software. As briefly outlined in this paper our studies demonstrate the achievable high-reliability in the fronthual network along with a guaranteed end-user service continuity without permanent interruption during live-migration of specific mobile network virtual functions. In addition, the temporary disruption time experienced by the end-user service during the function live-migration is reduced by more than 50% when using our designed container platform compared to conventional VM solutions.