Code-division multiplexing for in-service out-of-band monitoring of live FTTH-PONs

We propose, to the best of our knowledge, a novel in-service live fiber-to-the-home (FTTH) passive optical networks (PONs) management solution. Our solution uses a modified direct-sequence (DS) optical code-division multiplexing (OCDM) system and overcomes the optical time-domain reflectometry (OTDR) point-to-multipoint shortcomings. Our solution addresses various service provisioning and network maintenance challenges in PONs, alleviates their complexity, and reduces their operational cost. In addition, our system exploits passive devices (or encoders) to demark service provider ownership and responsibility from that of customers. Our OCDM-based management solution easily scales up from FTTH time-division multiplexing (TDM)-PON to WDM-PON and TDM/WDM-PON to support as many as a thousand customers, all using only one monitoring wavelength. We address the coding system and develop capacity curves for different PON scenarios. (c) 2007 Optical Society of America.