Predefined path selection methods for dynamic routing and wavelength assignment in WDM networks

Kim, J.; Lee, D.

doi:10.1109/ofc.2003.1247552

Cited by 2 publications

(2 citation statements)

References 6 publications

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“…The RWA algorithms in optical networks can be categorized into two groups [3]. The first group is the predefined path based RWA (PRWA), who considers the two aspects of the RWA issue sequentially by first finding a route from a predetermined set of alternate paths and then searching for an appropriate wavelength.…”

Section: Introductionmentioning

confidence: 99%

A Routing and Wavelength Assignment Algorithm in Optical Burst Switching Networks

Shi¹,

Liu²,

Qin³

et al. 2005

Journal of Optical Communications

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One-way resources reservation and distributed control scheme are two notable features of routing and wavelength assignment (RWA) in optical burst switching (OBS) networks. These two features make the initial routing of bursts, i.e., the selection of the routes and wavelengths at source nodes, dramatically influence the network performance, especially the networks with limited-range wavelength conversions (LWCs). In this paper, we present a RWA algorithm called pre-defined lightpath RWA (PL-RWA). In PL-RWA, initial routing of bursts is precisely designed to avoid wavelength contentions at intermediate nodes. At the network design stage, for each source-destination pair (s,d), a dedicated set of alternate Hghtpaths is predefined to guide the initial routing of the bursts of (s,d). The alternate lightpaths subject to the wavelength continuous constraint and are clash free. Source node s will pour the bursts destined for d into the alternate lightpaths predefined for (s,d) as many as possible. For the bursts that cannot be carried by the alternate lightpaths, the shortest path of (s,d) is selected as the route and wavelengths are assigned hop-by-hop in real time. Using alternate lightpaths, the randomness and uncertainty of one-way resources reservation under distributed control are diminished. The selection of alternate lightpaths is formulated as an integer programming (IP) and solved by a heuristic algorithm based on tabu search. Simulation results obtained for NSFNET show that our algorithm, which can greatly reduce not only burst loss probability but also the number of used wavelength conversions, has advantage over the current algorithms.

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Section: Introductionmentioning

confidence: 99%

A Routing and Wavelength Assignment Algorithm in Optical Burst Switching Networks

Shi¹,

Liu²,

Qin³

et al. 2005

Journal of Optical Communications

View full text Add to dashboard Cite

show abstract

“…3 The first group is the predefined path based RWA (PRWA), who considers the two aspects of the RWA issue sequentially by first finding a route from a predetermined set of alternate paths and then searching for an appropriate wavelength. The second group considers all paths between the source and the destination in the routing decision, which is accomplished by executing a dynamic shortest path algorithm with link costs obtained from network state information.…”

Section: Introductionmentioning

confidence: 99%

Ant algorithm in OBS RWA

Shi

Zhang

2005

SPIE Proceedings

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The current routing and wavelength assignment (RWA) algorithms in optical switching (OBS) networks usually adopt the shortest path between the source-destination pairs as the routes and assign wavelengths hopby-hop. There are two main problems exist in theses algorithms: (1) If there are common links among the shortest paths of different source-destination pairs, the one-way reservation protocol may cause congestion on these links while other links are underutilized, which may deteriorate the network performance, especially in an unsymmetrical network. (2) Few RWA algorithms take the fault recovery into consideration, which is important for the network to operate smoothly. An ant system based RWA algorithm is proposed in this paper to resolve these two problems. The destination nodes send ACKs back for each successfully received burst control packet (BCP). The ACKs are feed back along the same path as the one through which BCPs are forwarded. ACKs leave some "pheromone" along the path. The coming bursts will choose the output links with the probability proportioned to their pheromone intensity. Numerical results obtained from simulation show that our RWA algorithm can find the optimal routes adaptively and get a better burst drop probability performance compared with current RWA algorithms in an unsymmetrical network. Furthermore, our RWA algorithm is robust for fault recovery. When there are failures on some fibers, the bursts can be dynamically deflected to a suitable route without any extra information exchange among the switching nodes.

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Predefined path selection methods for dynamic routing and wavelength assignment in WDM networks

Cited by 2 publications

References 6 publications

A Routing and Wavelength Assignment Algorithm in Optical Burst Switching Networks

A Routing and Wavelength Assignment Algorithm in Optical Burst Switching Networks

Ant algorithm in OBS RWA

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