Modeling energy performance of C-RAN with optical transport in 5G network scenarios

• Published in: Journal of optical communications and networking 2016-11, Vol.8 (11), p.B21-B34
• Main Authors: Fiorani, Matteo, Tombaz, Sibel, Martensson, Jonas, Skubic, Bjorn, Wosinska, Lena, Monti, Paolo
• Format: Article
• Language: English
• Subjects: 5G mobile communication; 5G radio interfaces; 5G radio interfaces; Backhaul; BBU functionalsplit; Beamforming; Centralized radio access network(C-RAN); Energy consumption; Fronthaul; Midhaul; Optical transport; Array signal processing; Backhaul; Baseband; BBU functional split; Beamforming; Centralized radio access network (C-RAN); Complex networks; Computer architecture; Electric power utilization; Energy conservation; Energy consumption; Energy efficiency; Energy utilization; Fronthaul; Impact analysis; Light transmission; Long Term Evolution; Long Term Evolution (LTE); Midhaul; Mobile telecommunication systems; Network architecture; Optical transport; Power consumption; Power demand; Queueing networks; Radio; Radio access networks; Radio equipment; Radio interface; Radio transmission; Segments; Wavelength division multiplexing; Wireless telecommunication systems
• ISSN: 1943-0620; 1943-0639; 1943-0639
• DOI: 10.1364/JOCN.8.000B21

The deployment of new 5G wireless interfaces based on massive multiantenna transmission and beamforming is expected to have a significant impact on the complexity and power consumption of the transport network. This paper analyzes the energy performance of four radio access network (RAN) architectures, each one utilizing a different option for splitting the baseband processing functions. The radio segment is based on Long-Term Evolution (LTE) and 5G radio access technologies. The transport segment is based on optical wavelength division multiplexing, where coherent and direct detection transmissions are considered. The energy consumption of each RAN architecture is weighted against i) the benefits for the radio segment as a function of the level of centralization of the baseband processing functions and ii) the power consumption levels needed to accommodate the capacity generated at each base station. Results show that, with LTE radio interfaces, the energy consumption of the transport network amounts to only a few percent of the overall network power consumption. As a result, fully centralized LTE radio architectures are a viable option, with energy savings of at least 27% compared with conventional distributed architectures. On the other hand, with advanced 5G radio interfaces, centralized architectures, if not carefully designed, might become impractical due to the excessive energy consumption of the transport network (i.e., as a result of the huge capacity to be accommodated). This aspect can be mitigated via a careful joint design of the radio and the transport network (i.e., leveraging on appropriate optical transmission techniques and compromising where needed on the radio network performance).