Fiber- A nd FSO-Protected Connections for Long-Reach TWDM Access Architecture with Fault Protection

Abstract

In this paper, we propose a long-reach star-ring-based time- A nd wavelength-division-multiplexing passive optical network (TWDM-PON) by usingfiber- A nd free space optical (FSO)-protected architecture againstfiber breakpoint. Here, the newfiber-based and FSO-based optical network unit (ONU) modules are designed in the PON system to achieve the self-protected operation. Thus, the adjacent ONU is linked to produce thefiber-or FSO-based reconnections. Thus, 4-10 Gbit/s downstream and 10 Gbit/s upstream signals can be reached through 70 kmfiber transmission and a length of free space link without signal amplification and dispersion compensation. Moreover, the relationships of splitter ratio and FSO link length in the proposed TWDM access network are also analyzed and discussed.