FRONTIERNET - FREQUENCY-ROUTING-TYPE TIME-DIVISION INTERCONNECTION NETWORK

This paper describes a photonic time division multiplexing (TDM) highw ay switch, called FRONTIERNET, that uses optical frequency as routing information, This switch architecture can be applied to asynchronous t ransfer mode (ATM) switching systems, The N x N switch consists of N t unable frequency convertors and N frequency-division-multiplexed (FDM) output buffers connected through an N x N frequency router, The route r can interconnect N input highways with N output highways in a comple tely noninterfering way, It is possible to address each output highway uniquely by the choice of frequency (frequency routing) and each outp ut highway can receive any given frequency from only one input, This s witch architecture therefore has three advantages: its novel output bu ffering scheme achieves the best possible performance, there is no nee d for a complicated contention resolution mechanism between input high ways, and there is no splitting loss of the transmitted optical power, An experimental switch with a one-cell FDM buffer was constructed. Th e tunable frequency convertor based on fast tunable frequency lasers c an transmit high-speed optical cells to which frequencies are assigned on a cell-by-cell basis, The frequency router is an integrated-optic arrayed-waveguide grating 16 x 16 filter produced by using planar-ligh twave-circuit (PLC) technology, The one-cell FDM output buffer based o n optical fiber delay lines can store FDM cells and select only one ce ll at each timeslot over the output highway, A 2.5 Gb/s experimental s witch was successfully operated, And an experimental FDM loop buffer w as also demonstrated, This stores two cells at a data rate of 2.5 Gb/s , The bit error rate (BER) of the cells after up to 10 circulations is <10(-9), The performance of the buffer in terms of the probability of cell loss and the cell waiting time in the buffer is analyzed numeric ally, It is concluded that fewer optical buffers are needed to satisfy the desired probability of the cell loss compared with the convention al electronic buffers, The scale of the switch can be expanded in a mo dular fashion in two ways: using a multistage frequency router and a m ultistage switching network. And the multihop FRONTIERNET architecture is proposed to reduce the required frequency channels rather than the single-hop FRONTIERNET. The switch scale is also very easy to expand by connecting the frequency-router-based switching submodules.