(Non-)Reconfigurable Virtual Topology Design Under Multihour Traffic in Optical Networks

Abstract

This paper investigates offline virtual topology design in transparent optical networks under a multihour traffic demand. The main problem variant addressed here designs a reconfigurable virtual topology that evolves over time to more efficiently utilize network resources (the MH-VTD-R problem). The case of designing a static non-reconfigurable virtual topology that can accommodate the time-varying traffic (the MH-VTD-NR problem) is also considered. The objectives are to minimize: 1) the number of transceivers, which make up for the main network cost; and 2) the frequency of reconfiguration (for MH-VTD-R), which incurs additional overhead and potential service disruption. We formulate this multiobjective problem as an exact mixed integer linear program (MILP). Due to its high complexity, we propose a very efficient heuristic algorithm called Greedy Approach with Reconfiguration Flattening (GARF). GARF not only solves both (non-)reconfigurable problem variants, but it allows for tuning of the relative importance of the two objectives. Exhaustive experiments on real and synthetic traffic and comparison to previous proposals and bounds reveal the merits of GARF with respectto both solution quality and execution time. Furthermore, the obtained results indicate that the maximal transceiver cost savings achieved by the fully reconfigurable case may not be enough to justify the associated increase in reconfiguration cost. However, results show that an advantageous tradeoff between transceiver cost savings and reconfiguration cost can be achieved by a allowing a small number of virtual topology reconfigurations over time.Index Terms-Multihour traffic, reconfigurable virtual topology design, transparent optical networks.

Embedding IP Unique Shortest Path Topology on a Wavelength-Routed Network: Normal and Survivable Design

“…In each failure state (in addition to in the normal state), we need to ensure that the resultant lightpath topology still satisfies the unique shortest path condition for each source-destination node pair This is reflected through the following constraint: (13) 6) Survivability Constraint: In order for any lightpath topology to be survivable due to a single physical link failure, the main requirement is that the lightpath topology should be 2-connected, so that the removal of any lightpath link does not cause the topology to be disconnected. To incorporate this constraint, we use a theorem from [7], which uses the notion of cuts to ensure that the topology is redundant.…”

“…Lightpath and virtual topology design on optical networks has been extensively investigated; see, for example, [5], [13]- [15]. None of these works address IP unique shortest path routing requirements in designing the topology.…”

Algorithms for the Multi-Period Power-Aware Logical Topology Design With Reconfiguration Costs

“…Lagrangian relaxation of the planning problem is first proposed in [17] and then extended in [18]. Eventually, the greedy approach with reconfiguration flattening (GARF), also utilizing the tabu search meta-heuristic, is proposed in [19]. Finally, the concept of domination between traffic matrices (TMs) is proposed for large problem instances in [20,21].…”

How to slice the day: Optimal time quantization for energy saving in the internet backbone networks

“…The authors of [13] later presented a fast and efficient heuristic for the problem, which can also reduce the number of network reconfigurations. The first paper considering load adaptive energy saving with multiple time slices per day was [14], so that the network capacity can be adapted better to the actual traffic demand during the various time slices.…”