Reconfiguration and Dynamic Load Balancing in Broadcast WDM Networks

Baldine, I; Rouskas, GN

dc.contributor.author	Baldine, I	en
dc.contributor.author	Rouskas, GN	en
dc.date.accessioned	2014-03-01T01:48:42Z
dc.date.available	2014-03-01T01:48:42Z
dc.date.issued	1999	en
dc.identifier.issn	1387974X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25575
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0033440877&partnerID=40&md5=d16b7622bf3a8b96a31f6e9435f0b842	en
dc.subject	Broadcast optical networks	en
dc.subject	Dynamic load balancing	en
dc.subject	Reconfiguration	en
dc.subject	Wavelength division multiplexing (WDM)	en
dc.title	Reconfiguration and Dynamic Load Balancing in Broadcast WDM Networks	en
heal.type	journalArticle	en
heal.publicationDate	1999	en
heal.abstract	In optical WDM networks, an assignment of transceivers to channels implies an allocation of the bandwidth to the various network nodes. Intuition suggests, and our recent study has confirmed, that if the traffic load is not well balanced across the available channels, the result is poor network performance. Hence, the time-varying conditions expected in this type of environment call for mechanisms that periodically adjust the bandwidth allocation to ensure that each channel carries an almost equal share of the corresponding offered load. In this paper we study the problem of dynamic load balancing in broadcast WDM networks by retuning a subset of transceivers in response to changes in the overall traffic pattern. Assuming an existing wavelength assignment and some information regarding the new traffic demands, we present two approaches to obtaining a new wavelength assignment such that (a) the new traffic load is balanced across the channels, and (b) the number of transceivers that need to be retuned is minimized. The latter objective is motivated by the fact that tunable transceivers take a non-negligible amount of time to switch between wavelengths during which parts of the network are unavailable for normal operation. Furthermore, this variation in traffic is expected to take place over larger time scales (i.e., retuning will be a relatively infrequent event), making slowly tunable devices a cost effective solution. Our main contribution is a new approximation algorithm for the load balancing problem that provides for tradeoff selection, using a single parameter, between two conflicting goals, namely, the degree of load balancing and the number of transceivers that need to be retuned. This algorithm leads to a scalable approach to reconfiguring the network since, in addition to providing guarantees in terms of load balancing, the expected number of retunings scales with the number of channels, not the number of nodes in the network.	en
heal.journalName	Photonic Network Communications	en
dc.identifier.volume	1	en
dc.identifier.issue	1	en
dc.identifier.spage	49	en
dc.identifier.epage	64	en