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In this paper we present the architecture, operation, and the implementation of a prototype system, Flexible Access System (FAS), developed by CHT T.L. for FITL applications. FAS adopts fiber to the curb (FTTC) topology and provides POTS, ISDN BRA, and Ti services. The system consists of three main parts, namely, Fiber Central Office Terminal (FCOT) at switch side, Fiber Nodes (FN) at customer side, and a monitor station. FCOT and FNs are connected through an STM-1 fiber distribution ring.The hardware structure and the operation principle for each module are described. FAS contains the mux/demux module, POTS, ISDN, and Ti central office/customer service modules, operation module, and power module. In the design, each central office service module in FCOT simulates as a CPE to terminate signals from switch, and will separate the data and signaling and map them into DS1 format. Mux/demux module will add/drop these DS1s, put the operation information in data communication channel (DCC), and convert them to STM-1 optical link. Each customer service module in FN simulates respective switch line card to regenerate the signal for customers.The prototype system implementation confirms the benefits of introducing SDH addldrop technologies to FITL system to provide basic telecommunication services. The design experience reveals that the clock synchronization method and noise reduction technique can significantly influence the performance in such a system. The test results that demonstrate and verify the designed functionality and the service quality of the prototype system will be presented.

Ahstract-A heuristic multicasting traffic grooming algorithm which can easily route and assign the wavelength for transmission, and a QoS-promoted scheme for upstream transmission in FTTx optical networks are proposed. The heuristic algorithm can achieve the traffic grooming within a short period of time for any traffic types. The QoS-promoted scheme divides incoming packets of voice, video, data service into six priorities, whereas packets having less room before QoS requirements violation will be dynamically promoted to high priority, and thus can be transmitted earlier in metro WDMIFTTx network to guarantee the end-to-end QoS. The simulation results show that the QoS-promoted scheme achieves lower video packets dropped and lower packets delay than the DBAM scheme.