Dynamic energy savings in Cloud-RAN: An experimental assessment and implementation

Cloud Radio Access Network (C-RAN) is one of the most promising network architectures for next-generation mobile communication. Integrating multiple Base Band Units (BBUs) for signal processing in centralized BBU pools provides the opportunity to manage the utilization of processing resources more flexibly and in a more energy-efficient way. This paper demonstrates two approaches for dynamic energy saving in heterogeneous C-RAN networks by switching BBUs from sleep mode to operational mode, depending on changes in data traffic demand. To wake up BBUs, Wake-on-LAN (WoL) packets are sent either by the Remote Radio Head (RRH) in the first approach or by the controller in a BBU pool in the second approach. We implement and compare, in terms of wake-up latency, experimental prototypes using Software Defined Radio (SDR) for both approaches. Aiming at compliance to current LTE standards, the design and implementation of these prototypes has the potential to be applied to a larger scale C-RAN architecture in next-generation commercial mobile networks, including, but not limited to, 5G networks.