Iterative approach for optimizing a multistage interconnection network

Multistage interconnection architectures allow easy switching between different channels. There are many known algorithms for optimizing the interconnection net in terms of minimizing the number of alterations required for switching from one set of channels to a similar set. In optics, however, there exists the problem of implementation. Not all the routing architectures can be easily constructed optically, and there is an advantage in implementing routing architectures with a symmetric structure (e.g., perfect shuffle versus the nonsymmetric Banyan). Therefore an optical setup might be limited to the use of certain routing architectures. Here the authors present an algorithm for optimizing the routing scheme by minimizing the number of stages. The authors also show an algorithm for minimizing the number of changes required in a given routing scheme during shifting from one input-output connection to a similar connection.