Centralized in-service OTDR testing in a CWDM business access network

This paper describes "virtual common space", an access architecture that uses inexpensive "coarse" wavelength-division-multiplexing (CWDM) technology to extend the advantages of wavelength-division multiplexing (WDM) to business access applications. This new approach suggests new operations and diagnostic requirements. A wavelength-selective optical time-domain reflectometer using CWDM sources is demonstrated for such procedures. Some of the potential impairments that could arise from in-service monitoring on these systems are quantified.