Wavelength assignment algorithms for wavelength routed interconnection of LANs

This paper addresses the wavelength assignment issues in interconnecting op tical Local Area Networks (LANs) in which a wavelength cannot be reused for local connections. Multiple LANs are connected using a wavelength routing bridge that may or may not support wavelength conversion. Static and dynami c approaches to partitioning of wavelengths for local and global traffic ar e compared using analysis and simulations. Under the static scenario, the w avelength set is partitioned into fixed sets of local wavelengths and globa l wavelengths. Dynamic wavelength assignment allows all traffic to use all the wavelengths and thus provides greater statistical multiplexing at the e xpense of increased implementation complexity, It is found that static wave length assignment, the easiest algorithm to implement, is significantly out performed by dynamic algorithms. Several dynamic assignment algorithms are developed, and architectural issues in interconnecting optical networks are discussed. The dependence of the call blocking performance on system param eters, such as the local and global traffic statistics, and the number of a vailable wavelengths is examined in detail. An elegant outcome is developme nt of a simple, yet accurate, model to predict approximate blocking perform ance with an arbitrary number of LANs.