A bicriteria routing model for multi-fibre WDM networks

Abstract

All-optical WDM networks are characterised by multiple metrics (hop-count, cost, delay, available bandwidth, loss probability, reliability), but generally routing algorithms only optimise one metric. Having in mind the inherent limitations of this type of approach, it seems potentially advantageous in the development of multicriteria models capable of explicitly representing the different performance objectives and enabling to treat in a consistent manner the trade off among the various criteria. A bicriteria model for obtaining a topological path (unidirectional or symmetric bidirectional) for each lightpath request in a WDM network is proposed. The first criterion is related to bandwidth usage in the links (or arcs) of the network. The second criterion is the number of links (hops) of the path. The model resolution approach uses a k-shortest path algorithm as well as preference thresholds defined in the objective function space, combined with a Chebyshev distance to a reference point (which changes with the analysed preference region). The solution of this bicriteria model is a non-dominated topological path. A heuristic procedure is then used to assign wavelengths to the links. The performance of the bicriteria model is analysed by comparing it with two monocriterion approaches, using two test networks.

An exact method for constructing minimal cost/minimal SRLG spanning trees over optical networks

“…The automated selection procedure could be, in this case, an adaptation of the selection method for non-dominated light paths in WDM networks proposed in [45] which is partially based on the reference point based approach in [55]. The method combines the use of preference thresholds for the objective functions, defining priority regions in the objective functions space, with a Chebyshev distance to reference points.…”

“…The first objective seeks the selected links to be the least loaded, ensuring an increased global traffic carrying capability, and it is a type of metric previously used in single criterion and multicriteria routing optimization models for point to point connections over WDM networks such as in [44] (this model uses a lexicographic approach considering as metrics to be optimised the path length and congestion as a secondary criterion for path selection) and [45] (in this explicitly bicriteria model, topological paths are calculated seeking to optimise simultaneously the link bandwidth usage cost and the number of hops). Bicriteria models for routing over WDM networks, as these, have addressed only point to point routing problems (unicast routing) and used a single layer network representation, so that no resilience objectives are included.…”

Future research directions in design of reliable communication systems

“…In [50] a bicriteria model for calculating topological paths, corresponding to supported and unsupported non-dominated solutions, is described; after the selection of the topological path, wavelengths are assigned to the links, completely defining the lightpath. This model was extended in [127], for considering dedicated path protection.…”

Multicriteria path and tree problems: discussion on exact algorithms and applications

“…This approach was tested on a video-traffic routing model and several loopless paths were ranked in, at most, 24 milliseconds, on a network with 2000 nodes (and average node degree 4). Gomes et al (2009): More recently, motivated by a project with Portuguese Telecom Innovation, a bicriteria model was developed for obtaining a topological path (unidirectional or symmetric bidirectional) for each lightpath request in an all-optical wavelength routed WDM network. The resolution approach here proposed is closely related to those referred to above.…”