Survivable BBU Placement for C-RAN over Optical Aggregation Networks

Abstract

Centralized Radio Access Network (C-RAN) is a novel mobile network architecture, designed to effectively support the challenging requirements of future 5G mobile networks. Unlike Distributed RAN (D-RAN), in C-RAN, baseband units (BBUs) are located in a single physical location, called pool, connected to several Remote Radio Heads (RRHs) via the so-called fronthaul network. Following this centralization, designing a survivable C-RAN becomes crucial as BBU pool failures might cause service outage for large number of users. In this paper, we introduce the survivable BBU pool placement problem for C-RAN deployment over an optical aggregation network and formalize it by Integer Linear Programming (ILP). The ILP objective is to minimize the number of BBU pools, the number of used wavelengths and the computational resources. The results compare the aforementioned objectives and show the effect of the latency and of the transport-network capacity on the optimal solution.