Abstract :
The optical star network and its power budget and spectral-width limits are reviewed. A third capacity limit due to the bandwidth available within the switch for communicating the switch-control functions to the crosspoint elements of the switch is investigated. A pipelined switch processor and the communications bandwidth required within the switch to support the maximum amount of information transfer within that pipelined architecture are considered. Calculation results are presented for two examples, the switching of asynchronous transfer mode (ATM) cells and of data packets of longer duration, and the differing conclusions to which these two cases lead are compared. For short packets. such as in ATM, the power budgets are not a significant factor, and the bandwidth of the control channel is dominant. Increasing that bandwidth by the use of a parallel bus is indicated. For long packets, the power budget is much more important and the control channel less so. In this case, coherent detection adds significantly to the total switch capacity. The impact that these considerations may have on high-speed communications networks is discussed.<>
Keywords :
channel capacity; optical switches; packet switching; pipeline processing; time division multiplexing; ATM cells; asynchronous transfer mode; capacity limit; coherent detection; communications bandwidth; control channel; crosspoint elements; data packets; high-speed communications networks; multiwavelength switches; optical star network; optical-star packet switches; parallel bus; pipelined architecture; pipelined switch processor; power budget; spectral-width; switch-control functions; Asynchronous transfer mode; Bandwidth; Communication networks; Communication switching; Communication system control; High speed optical techniques; Optical fiber networks; Optical packet switching; Optical switches; Packet switching;
