Novel ring-based architecture for TWDM-PON with high reliability and flexible extensibility

Time and wavelength division multiplexed passive optical network (TWDM-PON) was determined as a primary solution to NG-PON2 by the full service access network (FSAN) in 2012. Since then, TWDM-PON has been applied to a wider set of applications, including those that are outage sensitive and expansion flexible. So the protection techniques with reliability and flexibility should be studied to address the above needs. In this paper, we propose a novel ring-based architecture for TWDM-PON. The architecture can provide reliable ring protection scheme against a fiber fault occurring on main ring (MR), sub-ring (SR) or last mile ring (LMR). In addition, we exploit the extended node (EN) to realize the network expansion conveniently and smoothly for the flexible extensibility. Thus, more remote nodes(RNs) and optical network units (ONUs) could access this architecture through EN. Moreover, in order to further improve reliability of the network, we design the 1: 1 protection scheme against the connected fiber fault between RN and EN. The results show that the proposed architecture has a recovery time of 17 ms under protection mode and the reliability of the network is also illustrated to be greatly improved compared to the network without protection. As the number of ONUs increases, the average cost of each ONU could be gradually reduced. Finally, the simulations verify the feasibility of the architecture.