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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01 Jan 2003
TL;DR: This dissertation addresses two connection-level reliability issues in cellular networks: how to limit the forced termination probability of handoff calls without sacrificing wireless resource utilization unnecessarily, and how to improve the restorability of existing radio access networks (RANs) cost-effectively.
Abstract: In recent years, we have witnessed an unprecedented growth of research and development in the field of cellular networks. There is currently a vision that future wireless technology will provide mobile users with at least similar services as those available to the fixed hosts. As the dependence on mobile terminals increases, mobile users will likely demand the same reliable service as of today's wireline telecommunications and data networks. This dissertation addresses two connection-level reliability issues in cellular networks: (1) how to limit the forced termination probability of handoff calls without sacrificing wireless resource utilization unnecessarily, and (2) how to improve the restorability of existing radio access networks (RANs) cost-effectively.
To address the first issue, we propose two novel mobility prediction schemes that incorporate real-time mobile positioning information. Unlike previous attempts, which have either assumed circular or hexagonal cell boundaries, our schemes are the first to take the irregular nature of cell boundaries into consideration. We also propose a dynamic resource reservation scheme that utilizes the outputs of our mobility prediction schemes. Both incoming and outgoing handoff predictions at each cell are utilized for computing the reservation target, so as to achieve more efficient handoff prioritization.
To address the second issue, we develop cost-effective design methods to enhance the restorability of existing RAN structures against single element failure scenarios. Mesh-restorable RAN structures are built from existing star and tree based topologies by adding new spans, and allocating spare capacity. Five different variants of span and path restoration schemes are considered; we develop both optimization formulations and heuristic algorithms to generate RAN designs for each restoration scheme. In our design methods, each span can have a different set of candidate transmission capacities that are determined by the actual deployment constraints. The costs associated with the candidate capacities can also be specified individually for each span; this allows true costs to be used, which are likely to be both location-dependent and capacity-dependent. It also allows the design methods to take advantage of the presence of any economy-of-scale effects, which are ignored by many existing spare capacity allocation methods.
2 citations
03 Dec 2007
TL;DR: The proposed algorithm can find k disjoint paths in an n-pancake graph where k les [n/2] and the maximum path length is bounded by [5n/3] + 6.
Abstract: Disjoint paths problems have attracted much attention due to its numerous applications in fault-tolerant routing. The pairwise disjoint paths problem is one of them. In this paper, we propose an algorithm for the pairwise disjoint paths problem in an pancake graph. The algorithm can find k disjoint paths in an n-pancake graph where k les [n/2]. The k disjoint paths can be constructed in O(kn) time and the maximum path length is bounded by [5n/3] + 6.
2 citations
TL;DR: A new model for routing in survivable ATM networks and a new parallel projection algorithm for solving the corresponding optimization problem are described.
Abstract: This paper describes a new model for routing in survivable ATM networks and a new parallel projection algorithm for solving the corresponding optimization problem. The proposed algorithm has application in general linear programming (LP). Numerical results for medium size networks are presented and discussed.
1 citations
Cites background or methods from "Optimal capacity placement for path..."
...The algorithm in [9] was developed to generate realistic survivable MAN/WAN networks, such as network 3 in [22] or network 2 in [41]....
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...Practically all research cited in this paper uses an explicit set of paths [6,22,34,39, 41]....
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...In the network dimensioning problem [6,22,34,41], link capacity is calculated so that in case of a failure there is enough spare capacity to face the restoration procedures....
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...IP models have also been proposed to route a whole traffic demand through a single path [41], or to reflect underlying discrete resources [22]....
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...This is the case of [34] (column generation outer algorithm with a revised simplex subsolver), [39] (IP with MINOS as subsolver) and [22] (IP, used CPLEX 3....
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TL;DR: The results show that the time-to-transmission halt for the first time exceeding 1 year can reach 99.999%, if the number of the independent concatenated links is greater than two and the granted maximal decrease ratio of the service transmission bandwidth.
Abstract: The new techniques, link capacity adjustment scheme (LCAS) and virtual concatenation not only make SDH/SONET networks accommodate the data service efficiently, but also provide a high-layer protection for client services, under which no spare capacity needs to be reserved for protection and the service transmission continues unless all concatenated links have failed. In this paper, we analyse the performance of this kind of protection in ring topology and mesh topology respectively. The results show that the time-to-transmission halt for the first time exceeding 1 year can reach 99.999%, if the number of the independent concatenated links is greater than two. In addition, the protection performance is analysed in detail given the granted maximal decrease ratio of the service transmission bandwidth. Copyright © 2005 AEIT.
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