| 1. |
- Monti, Paolo, et al.
(författare)
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Resource-efficient path-protection schemes and online selection of routes in reliable WDM networks
- 2004
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Ingår i: Journal of Optical Networking. - 1536-5379. ; 3:4, s. 188-203
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Tidskriftsartikel (refereegranskat)abstract
- Feature Issue on Next-Generation WDM Network Design and Routing (WDMN) The optimal choice of routing and wavelength assignment (RWA) for the working and protection path-pair of the newly generated demand request is often a complex problem in reliable wavelength-division-multiplexed (WDM) networks subject to dynamic traffic. The challenge is twofold: how to provide the required reliability level without over-reserving network resources and how to find a good solution of the RWA problem under constrained computational time. Two important contributions are made. First, the shared path protection (SPP) switching scheme is generalized to guarantee the required (differentiated) level of reliability to all arriving demands, while, at the same time, ensuring that they contain the required amount of reserved network resources. This generalization is referred to as SPP-DiR. Second, an approach for choosing the working and protection path-pair routing for the arriving demand is proposed. The approach is based on a matrix of preselected path-pairs: the disjoint path-pair matrix (DPM). Results show that, when the SPP-DiR scheme is applied, a small reduction in demand reliability corresponds to a significant reduction of the required network resources, when compared with the conventional SPP. In turn, the demand blocking probability may be reduced more than one order of magnitude. It is also shown that the DPM approach is suitable for obtaining satisfactory RWA solutions in both SPP-DiR and conventional SPP networks. The use of the DPM is most suited when the time for solving the RWA problem is constrained, e.g., when demand requests must be served swiftly.
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| 2. |
- Tacca, Marco, et al.
(författare)
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The disjoint path-pair matrix approach for online routing in reliable WDM networks
- 2004
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Ingår i: 2004 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-7. - 0780385330 ; , s. 1187-1191
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Konferensbidrag (refereegranskat)abstract
- In reliable wavelength division multiplexed (WDM) networks, the optimal choice of routing and wavelength assignment (RWA) for the working and protection path-pair is often a complex problem to solve. To cope with such problem complexity, this paper presents the disjoint path-pair matrix (DPM) approach. With the DPM approach, the RWA problem complexity - i.e., the size of the solution space - can be significantly reduced by limiting the number of candidate path-pairs considered in the optimization. Simulation results are collected using the DPM approach to solve the online RWA problem in a network based on the shared path protection switching scheme with differentiated reliability. When compared to the conventional k-shortest paths approach, the DPM approach requires up to one order of magnitude less candidate path-pairs. In addition, the DPM approach finds solutions with reduced hop length of both the working and protection paths by up to 3% and 14%, respectively.
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