Resilient cloud network mapping with virtualized BBU placement for cloud-RAN

Cloud Radio Access Network (C-RAN) will improve mobile radio coordination and resource efficiency by allowing baseband processing unit (BBU) functions to be virtualized and centralized, i.e., deployed in a BBU hotel. We consider a BBU hoteling scheme based on the concept of access cloud network (ACN). An ACN consists of virtualized BBUs (vBBUs) placed in metro cloud data centers (metro DCs). A vBBU is connected to a set of remote radio heads (RRHs). ACN resiliency against network and processing failures is critical for C-RAN deployments. Hence, in this study, we propose three protection approaches: 1+1 ACN protection, 1+1 ACN and vBBU protection, and partial ACN protection. Simulation results show that both 1+1 ACN and 1+1 ACN and vBBU protection requires large capacity for backup to provide 100% survivability for singlelink and single-DC failures. As a result, we suggest a partial ACN protection approach which provides degraded services with only 8% additional network resources.