PHOTONIC ACCESS CONCENTRATOR FOR ATM GIGABIT SWITCHING FABRICS

In future broadband communication networks the interest for purely pho tonic switches is due to the bandwidth mismatch between optical transm ission networks and electronic switching nodes, Photonic ATM switching fabrics mainly based on wavelength-switching stages are therefore bei ng studied, to implement high capacity switches with also concentratio n, multiplexing and demultiplexing functions, using state-of-the-art p hotonic technology, The architecture of an ATM photonic access concent rator is described in this paper, illustrating the design and implemen tation of its basic subsystems, the traffic concentrator and the cell multiplexer, The design guidelines are outlined in detail referring to an example, where 128 user lines at 622 Mb/s are given access to 4 ou tlets at 2.488 Gb/s, The corresponding implementation, based on the sy stematic use of cell wavelength encoding, makes use either of well/kno wn photonic components, such as Fabry-Perot filters, fiber delay lines , splitters and combiners, either of recently developed de,ices, like high-speed optical gates and tunable filters and lasers, Finally, the system feasibility is demonstrated presenting the results obtained on a reduced size and speed experimental setup of the cell multiplexer.