Centralized Buffering and Lookahead Wavelength Conversion in Multistage Interconnection Networks

In this paper, methods to alleviate the problem of internal blocking in interconnection networks based on WDM are studied. In an ordinary 8x8 Omega network, only 10% of all permutations are permissible in one pass, and it gets worse with larger switches. However, using WDM technology, the performance of these networks can be improved. In this paper, several architectures based on Omega network using the WDM technology are considered and in turn algorithms to resolve the problem of internal blocking in a centralized fashion are introduced. Performance of the Omega network is analyzed by simulation. It is shown that by using a few buffers and lookahead wavelength converters a considerable amount of improvement in the system performance is achieved.