Energy Consume Analysis for Ring-Topology TWDM-PON Front-Haul Enabled Cloud RAN

Abstract

Cloud radio access network (C-RAN) is a new architecture to meet the ever increasing internet data traffic. In particular, the operating expense (OPEX), mainly the energy consumption, of C-RAN is an issue of common concern. Several former works in this area lacked the essential consideration for the optical front-haul part, as a result that it cannot provide overall energy consumption study for the whole system. In this paper, we analyze the energy consume problem in a new C-RAN architecture, i.e., the ring-topology time-wavelength division multiplexing (TWDM) passive optical network (PON) front-haul enabled C-RAN, considering the requirements for large transmission capacity, high energy efficiency, and the appropriate utilization in the large-scale and densely populated cities. After bringing in this optical front-haul and considering the quality of service, a network traffic modeling is provided to analyze the energy problem based on queueing theory. We also conduct the network optimization to ensure that the system works in the most energy-efficient state. Besides, the energy comparisons among the ring-topology TWDM-PON front-haul enabled C-RAN, the time division multiplexing (TDM) PON enabled C-RAN and the ring-topology TWDM-PON-LTE architecture have also been made. According to the numerical results, the new C-RAN, after energy optimization, can save up to 58.1% energy compared with the TWDM-PON-LTE architecture, and also has a slight advantage over the TDM-PON enabled C-RAN (saving more than 2% energy), demonstrating its broad application prospects and large potential in the future.