Routing and path multicoloring

Nomikos, C; Pagourtzis, A; Zachos, S

dc.contributor.author	Nomikos, C	en
dc.contributor.author	Pagourtzis, A	en
dc.contributor.author	Zachos, S	en
dc.date.accessioned	2014-03-01T01:17:01Z
dc.date.available	2014-03-01T01:17:01Z
dc.date.issued	2001	en
dc.identifier.issn	0020-0190	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14334
dc.subject	Algorithms	en
dc.subject	All-optical networks	en
dc.subject	Parallel fiber links	en
dc.subject	Path coloring	en
dc.subject	Routing	en
dc.subject.classification	Computer Science, Information Systems	en
dc.subject.other	Algorithms	en
dc.subject.other	Approximation theory	en
dc.subject.other	Bandwidth	en
dc.subject.other	Color image processing	en
dc.subject.other	Edge detection	en
dc.subject.other	Graph theory	en
dc.subject.other	Mathematical transformations	en
dc.subject.other	Optical links	en
dc.subject.other	Parallel processing systems	en
dc.subject.other	Routers	en
dc.subject.other	Path multicoloring	en
dc.subject.other	Optical communication	en
dc.title	Routing and path multicoloring	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0020-0190(01)00167-3	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0020-0190(01)00167-3	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	In optical networks it is important to make an optimal use of the available bandwidth. Given a set of requests the goal is to satisfy them by using a minimum number of wavelengths. We introduce a variation to this well known problem, by allowing multiple parallel links, in order to be able to satisfy any set of requests even if the available bandwidth is insufficient. In this new approach the goal is to use a minimum number of active links and thus reduce network pricing. In graph-theoretic terms, given a graph, a list of pairs of vertices, and a number of available colors, the goal is to route paths with the given pairs of vertices as endpoints and to find a color assignment to paths that minimizes color collisions over all possible routings and colorings. We present efficient algorithms for simple network topologies. For chains our solutions are optimal; for stars and rings - where it is NP-hard to solve the problem optimally - our solutions are approximate within a factor two of the optimal solution. The key technique involves transformation to edge coloring of bipartite graphs. For rings we also present a 2-approximation algorithm, for a variation of the problem, in which the routing is already prescribed. (C) 2001 Elsevier Science B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Information Processing Letters	en
dc.identifier.doi	10.1016/S0020-0190(01)00167-3	en
dc.identifier.isi	ISI:000171737000006	en
dc.identifier.volume	80	en
dc.identifier.issue	5	en
dc.identifier.spage	249	en
dc.identifier.epage	256	en