Optimal capacity placement for path restoration in STM or ATM mesh-survivable networks
TL;DR: A method for capacity optimization of path restorable networks which is applicable to both synchronous transfer mode (STM) and asynchronous transfermode (ATM) virtual path (VP)-based restoration and jointly optimizing working path routing and spare capacity placement.
Abstract: The total transmission capacity required by a transport network to satisfy demand and protect it from failures contributes significantly to its cost, especially in long-haul networks. Previously, the spare capacity of a network with a given set of working span sizes has been optimized to facilitate span restoration. Path restorable networks can, however, be even more efficient by defining the restoration problem from an end to end rerouting viewpoint. We provide a method for capacity optimization of path restorable networks which is applicable to both synchronous transfer mode (STM) and asynchronous transfer mode (ATM) virtual path (VP)-based restoration. Lower bounds on spare capacity requirements in span and path restorable networks are first compared, followed by an integer program formulation based on flow constraints which solves the spare and/or working capacity placement problem in either span or path restorable networks. The benefits of path and span restoration, and of jointly optimizing working path routing and spare capacity placement, are then analyzed.
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15 Mar 2012
TL;DR: This paper considers the multi-commodity flow problem, and solves minimum-cost linear-programming to control path flow rate routing decisions triggered by the changes in the cost coefficients.
Abstract: The main focus of this paper is to understand how congestion due to link failure propagates to successive links, and how well the network maintains system flow under abnormal conditions. We consider the multi-commodity flow problem, in which each commodity (origin-destination pair) uses k link-disjoint paths to satisfy flow rate demands. The congestion in the links is used to calculate the prices of the links which affect the cost of travelling. We solve minimum-cost linear-programming to control path flow rate routing decisions triggered by the changes in the cost coefficients. We conclude that efficient path flow rate re-routing in response to the congestion in the links could contribute significantly to network survivability1.
1 citations
01 May 2005
TL;DR: The recent work of CCNR Lab in the study of TDM design and implementation in a star-based network and node and network architectures are considered for the support of both the centralized and distributed algorithms.
Abstract: Time-division-multiplexing (TDM) technique provides good granularity and response in high-speed networks. This paper presents the recent work of CCNR Lab in the study of TDM design and implementation in a star-based network. Node and network architectures are considered for the support of both the centralized and distributed algorithms. Performance evaluations have been carried out, and optimization is considered
1 citations
Cites background from "Optimal capacity placement for path..."
...Keywords: optical TDM, time slot assignment, star network, distributed and centralized algorithm, AAPN....
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03 Nov 2003
TL;DR: Neural-network-based optical network restoration is illustrated over an example in which multiple classes of traffic are considered and optimal routing and wavelength assignment is carried out.
Abstract: Neural-network-based optical network restoration is illustrated over an example in which multiple classes of traffic are considered. Over the preplanned primary and backup capacity, optimal routing and wavelength assignment is carried out. In case of a network failure, protection routes and optimum flow values on these protection routes are extracted from a previously trained feed-forward neural network which is distributed over the optical data communications network.
1 citations
09 May 2005
TL;DR: This work investigates topology planning with respect to minimum topology cost and total capacity requirements for dedicated and shared path protection against single and dual failures.
Abstract: The design of an appropriate physical topology is an important task when planning mesh transport networks. In order to be able to survive span or node outages, it is essential to provide diverse routes. However, the provisioning of edges involves high costs in terms of physical ducts and the equipment with transmission capacity. The growing demand for reliability causes network providers to consider not only single but also dual failure scenarios. This work investigates topology planning with respect to minimum topology cost and total capacity requirements for dedicated and shared path protection against single and dual failures. We develop mathematical models and investigate a case study.
1 citations
Additional excerpts
...Edge lengths are determined by the haversine formula [8]....
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01 Jan 2003
TL;DR: The results show that backupmultiplexing improves the utilization of channels but requires significant computing capacity under a fixed computing capacity budget, and the technique is useful in cases where there is little time disjointness among SLDs.
Abstract: This article addresses the problem of defining work- ing and protection paths for Scheduled Lightpath Demands (SLDs) in an optical transport network. An SLD is a demand for a set of lightpaths (connections), defined by a tuple (s, d, TI, a, w), where s and d are the source and destination nodes of the lightpaths, n is the number of requested lightpaths and a, w are the set-up and tear-down dates of the lightpaths. The problem is formulated as a combinatorial optimization problem where the objective is to minimize the number of channels required to instantiate the lightpaths. Two techniques are used to achieve this goal: channel reuse and backup-multiplexing. The former consists of assigning the same channel (either working or spare) to several lightpaths, provided that these lightpaths are not simultaneous in time. The latter consists of sharing a spare channel among multiple lightpaths. A spare channel cannot be shared if two conditions hold: a) the working paths of these lightpaths have at least one span in common and b) these lightpaths are simulta- neous in time. In the other cases, the spare channel can be shared. We propose a Simulated Annealing (SA) based algorithm to find approximate solutions to this optimization problem since finding exact solutions is computationally intractable. The results show that backupmultiplexing improves the utilization of channels but requires significant computing capacity. Under a fixed computing capacity budget, the technique is useful in cases where there is little time disjointness among SLDs. Index Terms- Scheduled demands, optimization, protection, simulated annealing.
1 citations
References
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Book•
16 Feb 1970
TL;DR: Interestingly, integer programming and network flows that you really wait for now is coming, it's significant to wait for the representative and beneficial books to read.
Abstract: (1970). Integer Programming and Network Flows. Journal of the Operational Research Society: Vol. 21, No. 4, pp. 500-501.
638 citations
TL;DR: Self-healing network techniques suitable for ATM networks in order to realize a high-reliablity B-ISDN are proposed and high-speed restoration technique which exploits the benefits of the VP is proposed and described.
Abstract: This paper proposes self-healing network techniques suitable for ATM networks in order to realize a high-reliablity B-ISDN. First, the characteristics of the virtual paths (VP) and their influence on failure restoration are discussed. A high-speed restoration technique which exploits the benefits of the VP is then proposed and described. The technique simplifies the message transmission processes and reduces the number of generated messages by using preassigned backup virtual paths. Next, the scheme used to design the backup VP routes and spare resource distribution for each link is proposed in order to create a network that applies the proposed restoration scheme. Next, self-reconstruction techniques of backup virtual paths are proposed for the realization of a reversionless restoration cycle. Finally, the feasibility of the distributed control operation is discussed. >
233 citations
TL;DR: A comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration, and the hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences.
Abstract: In the development of technologies for span failure restoration, a question arises about the restoration rerouting characteristics to be specified. In theory, maximal rerouting capacity is obtained with a maximum flow (Max Flow) criterion. However, rerouting that realizes the k-successively shortest link disjoint paths (KSP) may be faster, easier, and, in distributed implementation, more robust than a distributed counterpart for Max Flow. The issue is, therefore, what the restoration capacity penalty is if KSP is used instead of Max Flow. To explore this tradeoff, the authors present a comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration. The comparison applies to both centrally controlled and distributed restoration systems. Study methods include exhaustive span failure experiments on a range of network models, and parametric and analytical investigations for insight into the factors resulting in KSP versus Max Flow differences. The main finding is that KSP restoration capacity is more than 99.9% of that from Max Flow in typical network models. The hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences. The hypothesis is tested experimentally and used to develop analytical bounds which agree well with observed results. These findings and data are relevant to standards makers and equipment developers in specifying and engineering future restorable networks. >
199 citations
NEC1
TL;DR: In order to achieve fast restoration, a distributed control mechanism that is applicable to both line and path restoration is proposed, and the shared use of spare channels for various failure scenarios, including multiple failure cases, are allowed.
Abstract: With the advent of networking technologies intelligent network elements, such as the digital cross-connect system (DCS), will make it possible to dynamically reconfigure a network for restoration purposes. Both restoration control of DCSs and spare-channel design issues are presented, and how they work together so that a fast and economical SONET self-healing network is obtained. In order to achieve fast restoration, a distributed control mechanism that is applicable to both line and path restoration is proposed. The proposed method allows the shared use of spare channels for various failure scenarios, including multiple failure cases, so that the efficient use of spare channels can be achieved. A linear-programming-based scheme is proposed to obtain spare-channel assignment, where a network-flow technique is used. Through a simulation study, a fast and economical self-healing network is verified. >
193 citations
"Optimal capacity placement for path..." refers background or methods in this paper
...Previous work used an IP approach based on -flow -cut considerations to solve the spare capacity placement problem in a span-restorable network [4], [11], [20]....
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...Issues related to the restoration mechanisms themselves are addressed in related works [1], [2], [4], [21], [27]....
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Proceedings Article•
01 Jan 1987
180 citations