Faster algorithms for optical switch configuration

All-optical networks using wavelength division multiplexing are increasingly coming to be regarded as the technology of choice for the next generation of wide-area backbone networks. These networks incorporate optical switches that employ the concept of Latin Routers for assigning wavelengths to routes. The issue of maximizing wavelength utilization at these switching devices is of great importance since it lends to significant improvements in overall network performance. In this paper we present two fast approximation algorithms-GREEDY and MATCH for the problem of maximizing wavelength utilization at Latin Routers. These are the first known polynomial-time approximation algorithms for the problem of maximizing the number of entries that can be added to a partially filled Latin Square that achieve non-trivial worst-case performance guarantees. These algorithms are easily implementable and have very small constants in their running times making them eminently suitable far actual use in real-world optical switches. We also provide strong experimental evidence to show that, in practice, these algorithms are near-optimal