Abstract

Optical fibers are increasingly finding their way into the emerging broadband access networks. Worldwide, related projects are in progress in which optical fibers are pushed towards the subscribers’ premises in order to implement broadband FTTx systems where these systems are segmented into FTTC, FTTB, or even FTTH, i.e. Fiber to the Cabinet/Curb, Building and Home. However, a simple replacement of the legacy copper local loop structure by fiber technology would lead to a very fiber rich infrastructure. The resulting large amount of fiber cables, connectors and splices as well as floor space requirements, fiber management difficulties etc. would call for considerable investments to set-up such an analogous network topology. To enhance the utilization of implemented or planned fiber routes and to minimize fiber deployment costs, wavelength multiplexing techniques exhibiting various channel spacing can be used. Beside Band Wavelength Division Multiplexing (BWDM, channel spacing >50 nm) that permits bidirectional signal transport over a single fiber, the application of Coarse Wavelength Division Multiplexing (CWDM) for provisioning of high-speed broadband services in access networks is rapidly gaining popularity due to the benefit of low-cost CWDM devices with relaxed component tolerances but with a compromise in channel multiplexing capabilities.

© 2005 Optical Society of America