Efficient algorithms for wavelength rerouting in WDM multi-fiber unidirectional ring networks
| Autor: | Gurusamy Mohan, C. S. R Murthy |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Computer Networks and Communications
Computer science Optical links Multifiber unidirectional ring networks Blocking (statistics) Multiplexing Wavelength rerouting Fiber optic networks Electric network topology Wavelength-division multiplexing Optical communication Optical fibers Time complexity Constraint theory Circuit switching Ring (mathematics) business.industry Parallel move-to-vacant wavelength retuning (MTV-WR) Telecommunication traffic Wavelength Wavelength division multiplexing Congestion control (communication) Routing (electronic design automation) business Algorithms Computer network |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0140-3664 |
| DOI: | 10.1016/s0140-3664(98)00239-4 |
| Popis: | In this article, we consider wavelength rerouting in wavelength-routed Wavelength-Division Multiplexed (WDM) multi-fiber unidirectional ring networks with circuit switching. The wavelength continuity constraint imposed by WDM networks leads to poor blocking performance. Wavelength rerouting is a viable and cost effective mechanism that can improve the blocking performance by rearranging certain existing lightpaths to accommodate a new request. Recently, in Ref. [1], a rerouting scheme called 'Parallel Move-To-Vacant Wavelenth Retuning (MTV-WR)' with many attractive features such as shorter disruption period and simpler switching control has been proposed. A polynomial time rerouting algorithm has also been proposed in Ref. [1] to minimize the weighted number of rerouted lightpaths in WDM networks with the parallel MTV-WR rerouting scheme. However, this algorithm is not time optimal and works correctly when the fiber links, wavelength channels, and lightpaths are all bidirectional. We present here a time-optimal rerouting algorithm to minimize the number of rerouted lightpaths in wavelength-routed WDM multi-fiber unidirectional ring networks with parallel MTV-WR rerouting scheme. This algorithm requires only O(NFW) time units, where N is the number of nodes in the network, F is the number of fiber links between two consecutive nodes, and W is the number of wavelength channels available on a fibre link. We also present on O(NF2W) time rerouting algorithm to minimize the weighted number of rerouted lightpaths. The simulation results show that the rerouting algorithms improve the blocking performance considerably and only very few lightpaths are required to be rerouted per rerouting. The results also show that, for a given network load per wavelength per fiber, increasing the number of wavelengths or the number of fibers, leads to an improved performance by the networks with rerouting, without any rerouting and with full wavelength conversion capability at the routing nodes. ? 1999 Elsevier Science B.V. |
| Databáze: | OpenAIRE |
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