BBU location algorithms for survivable 5G C-RAN over WDM
Abstract New 5G radio access network is expected to offer competitive advantages in terms of cost, quality of service and mobility, that make it attractive for service providers. The resilience of this part of the network is consequently essential to provide high availability and service continuity in case of failure. This study focuses on heuristic solutions to design and operate the fronthaul network based on the Centralized Radio Access Network (C-RAN) concept. Facility Location Algorithms (FLA) are proposed to assign primary and backup functionalities to Baseband Unit (BBU) hotels and ensure availability in case of a single BBU hotel or link failure. Sharing techniques are applied to BBU hotel ports and transport wavelengths for hl cost-efficient design. The goal is to minimize the number of active BBU hotels while providing full coverage to all Remote Radio Units (RRU). Numerical results evaluate cost in relation to main design constraints, namely the number of hops allowed to reach primary and backup BBU hotel. The number of BBU hotels is compared for different location algorithms, showing that a proposed extension of a classical FLA, by including resilience, allows to obtain the best results both in terms of BBU hotels and shared ports. However, the need of suitable trade-off between the number of BBU hotels and the required wavelengths is outlined, depending on relative costs.