Strict-Sense Nonblocking Conditions for the log2?N-1 Multirate Switching Fabric for the Discrete Bandwidth Model

The article discusses the strict-sense nonblocking conditions derived for the log2?N-1 multirate switching fabric for the discrete bandwidth model at the connection level. Architecture of the log2?N-1 switching fabric was described in previous study; however, conditions for the multirate discrete bandwidth model as well as comparison with different structures have not been published before. Both sufficient and necessary conditions were introduced and proved in this study. A few numerical examples which help to understand an idea of the multirate bandwidth model for the log2?N-1 switching fabrics were delivered as well. Additionally a comparison of achieved results to the banyan switching structures and a comparison of the costs of all mentioned in this study structures expressed as the number of optical elements were done.