摘要
In the literature, research has been published extensively on how one achieves exact emulation of First In First Out (FIFO) multiplexers for fixed-size cells (or packets) using optical crossbar Switches and fiber Delay Lines (SDL). In this paper, we go a step further and propose a new architecture that achieves exact emulation of FIFO multiplexers for variable length bursts. Our architecture consists of two blocks: a cell-scheduling block and a FIFO multiplexer for fixed-size cells. Both blocks are made of SDL units. The objective of the cell-scheduling block is to schedule cells in a burst to the right input at the right time so that cells in the same burst depart contiguously from the multiplexer for fixed-size cells. We show that cell scheduling can be done efficiently by keeping track of a single state variable, called the total virtual waiting time in this paper. Moreover, the delay through the cell-scheduling block is bounded above by a constant that only depends on the number of inputs and the maximum number of cells in a burst. Such a delay bound provides a limit on the number of fiber delay lines needed in the cell-scheduling block. © 2006 IEEE.