We introduce a trafic model for circuit switched alloptical networks (AONs) which we then use to calculate the blocking probability along a path for networks with and without wavelength changers.We investigate the effects of path length, switch size, and interference length (the expected number of hops shamed by two sessions which share at least one hop) on blocking probability and the ability of waveiength changers to improve performance.Our model correctly predicts unobvious qualitative behavior demonstrated in simulations by other authors.

Abstract-We present a new algorithm which creates redundant trees on arbitrary node-redundant or link-redundant networks. These trees are such that any node is connected to the common root of the trees by at least one of the trees in case of node or link failure. Our scheme provides rapid preplanned recovery of communications with great flexibility in the topology design. Unlike previous algorithms, our algorithm can establish two redundant trees in the case of a node failing in the network. In the case of failure of a communications link, our algorithm provides a superset of the previously known trees.

am 1) epar t men t of Electrical Engineering 1J 11 i ve r s i t y of Was hi 11 g t on Seattle, WA 98195 AbstractWe propose a new algorithrn for the dynamic centralized wavelength assignment problem in fixed-routing WDM networks without wavelength conversion. The blocking perforiiiance of our algorithiii is better in many cases (and no worse in the cases we studied) than other previously proposed algo rat hiiis. The perform an ce am proveinent of our algorithm over other algorithins i s high for multi-fiber ring networks with a moderate number of fibers per link. In a multi-fiber mesh-torus network, the difference in performance is not as significant, but the blocking probabilities for all algorithms approach those achievable b y wavelength conversion as the number of fibers per link increases. We also extend an earl i w analytical model for predicting the blocking probability with and tuzthout wavelength conversion t o dense multi-fiber networks. Finally, our siiriulation results on multi-fiber rings and inesh-tort reveal surprising results about the benefits of wavelcngth conversion as the number of fibers per link incrpases.

Abstract-We introduce a traffic model for circuit-switched all-optical networks which we then use to calculate the blocking probability along a path for networks with and without wavelength changers. We investigate the effects of path length, switch size, and interference length (the expected number of hops shared by two sessions which share at least one hop) on blocking probability and the ability of wavelength changers to improve performance. Our model correctly predicts unobvious qualitative behavior demonstrated in simulations by other authors.