Traffic-Aware Heuristic BBU-RRH Switching Scheme to Enhance QoS and Reduce Complexity

Cloud Radio Access Network (C-RAN) is a new architecture that has been proposed to enable the current hardware to meet the ever-increasing traffic demand, as well as reducing the energy consumption of mobile base stations. This paper mainly focuses on two components of C-RAN, namely Remote Radio Heads (RRH) and Baseband Processing Unit (BBU) pool. The method of association of these two components could potentially affect the Quality of Service (QoS) and energy consumption level of the system. The connection between RRH(s) and BBU(s) is logical in C-RAN, which means that the association of RRH(s) to BBU(s) can be dynamically adjusted. Thus, a BBU-RRH switching scheme is required to manage the computational resource that the BBU pool possesses. This paper proposes a switching algorithm that works in conjunction with the knowledge of the traffic pattern of an area. This algorithm not only reduces the number of BBUs used in comparison with the traditional approach, but also decreases the number of switches required while maintaining a satisfactory level of service. In order to achieve this, the proposed algorithm reduces or limits the load of BBUs when the overall traffic of a BBU is on the rise, and vice versa. Finally, the simulation results illustrate that the proposed algorithm reduces the switching complexity and improves QoS while achieving significant reduction of BBU usage in comparison to traditional RAN.