Recent progress in optical access networks

Summary form only given. Because local loop distribution systems must be reliable, robust, and inexpensive, early passive optical network (PON) proposals emphasized broadcast architectures. These networks employ existing technology in a cost-effective manner and enable fiber to be deployed early. Concerns about ultimate capacity and network operations prompted wavelength-division multiplexing (WDM) PONs to be proposed and demonstrated shortly thereafter. Perceived component costs made implementation unrealistic. Recently, however, component and architecture research has re-opened WDM as a possible access strategy.