Optical techniques for WDM metropolitan area and access networks

We discuss several optical techniques that have been used to permit desirable optical fiber network functions to be implemented on WDM metropolitan area and access networks with an eye towards minimizing network cost. First, we examine the use of optical bands for connectivity in regional networks and service segregation in local access networks. This function, a form of optical add/drop multiplexing (OADM), permits bypass in metro networks and service segregation in access networks to be implemented with passive optical components. We also illustrate methods by which WDM networks can be used with non-WDM components. These methods are expected to be more cost-effective than strict WDM components, since they can be modular and produced in high volumes