On-line routing in all-optical networks

Yair Bartal, Stefano Leonardi

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

27 Scopus citations


The paper deals with on-line routing in WDM (wavelength division multiplexing) optical networks. A sequence of requests arrives over time, each is a pair of nodes to be connected by a path. The problem is to assign a wavelength and a path to each pair, so that no two paths sharing a link are assigned the same wavelength. The goal is to minimize the number of wavelengths used to establish all connections. We consider trees, trees of rings, and meshes topologies. We give on-line algorithms with competitive ratio Ω(log n) for all these topologies. We give a matching Ω(log n) lower bound for meshes. We also prove that any algorithm for trees cannot have competitive ratio better than Ω(log n/log logn). We also consider the problem where every edge is associated with parallel links. While in WDM technology, a fiber link requires different wavelengths for every transmission, SDM (space division multiplexing) technology allows parallel links for a single wavelength, at an additional cost. Thus, it may be beneficial in terms of network economics to combine between the two technologies (this is indeed done in practice). For arbitrary networks with Ω(log n) parallel links we give an on-line algorithm with competitive ratio Ω(logn).

Original languageAmerican English
Title of host publicationAutomata, Languages and Programming - 24th International Colloquium, ICALP 1997, Proceedings
EditorsPierpaolo Degano, Roberto Gorrieri, Alberto Marchetti-Spaccamela
PublisherSpringer Verlag
Number of pages11
ISBN (Print)3540631658, 9783540631651
StatePublished - 1997
Externally publishedYes
Event24th International Colloquium on Automata, Languages and Programming, ICALP 1997 - Bologna, Italy
Duration: 7 Jul 199711 Jul 1997

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference24th International Colloquium on Automata, Languages and Programming, ICALP 1997

Bibliographical note

Publisher Copyright:
© Springer-Verlag Berlin Heidelberg 1997.


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