Physical layer monitoring in 8-branched PON-based i-FTTH

This paper reports a novel physical layer monitoring technique called Centralized Failure Detection System (CFDS) based on the use of an optical time domain reflectometry (OTDR) and integrated with inexpensive additional optical devices at the middle of the network system for monitoring the fiber plant of a wide range of passive optical network (PON) based intelligent fiber-to-the-home (i-FTTH) in the background during network operation and determining the faulty branch as well as the fault parameters. Access Control System (ACS) has been developed to handle the centralized line detection for diverting the OTDR pulse signal from central office (CO) to bypass the filter and connect to each corresponding fiber link in drop section. The design and implementation of this integrated hardware/software system enable each lines' status can be observed and monitored at static point where the OTDR injecting the signal. All OTDR measurements are transmitted into remote workstation for centralized monitoring and advanced analyzing.