Abstract
There are several recent advances in the constructions of conflict-free optical queues using optical Switches and fiber Delay Lines (SDL). Many of these conflict-free optical queues are constructed by 2x2 switches and thus suffer from the notorious crosstalk problem. To alleviate the crosstalk problem,it is suggested in the literature that one should avoid routing two packets to the same 2x2 switch at the same time. A construction with such a property is called crosstalk-free. Our first contribution of this thesis is to extend the two-step method by Deng and Lee[22] to a three-step method that converts a conflict-free SDL element into a crosstalk-free SDL element. For certain optical queues, including linear compressors, linear decompressors, and non-overtaking delay lines, an additional step (the fourth step in our thesis) can be taken to further reduce the construction complexity. For such optical queues, one only needs 1 more 2x2 switch than the original construction. Our second contribution of this thesis is to provide worst case analysis of the signal-to-noise ratio (SNR) in both the original conflict-free SDL element and the converted crosstalk-free SDL element. Closed-form expressions for the worst case SNRs in both SDL elements are obtained. These expressions show that the gain of the worst case SNR in the converted crosstalk-free SDL element is quite substantial. Various computer simulations for the average case are also preformed to further verify our finding in the worst case.