The Experts below are selected from a list of 26571 Experts worldwide ranked by ideXlab platform

Zuqing Zhu - One of the best experts on this subject based on the ideXlab platform.

  • power efficient Protection with directed p cycles for asymmetric Traffic in elastic optical networks
    Journal of Lightwave Technology, 2016
    Co-Authors: Fen Zhou, Shilin Xiao, Zuqing Zhu
    Abstract:

    In this paper, we investigate power-efficient directed preconfigured cycles ( $p$ -Cycles) for asymmetric Traffic Protection in elastic optical networks (EONs) against single link failure. Owing to the advantage of distinguishing Traffic amount in two directions, directed $p$ -cycles consume low power by allocating different spectrum slots and modulation formats for each direction. A mixed integer linear programming (MILP) model is formulated to minimize total power consumption, which takes into account directed cycle generation, spectrum allocation, modulation adaptation, and Protection capacity. To increase the scalability, the MILP model is decomposed, and a two-step approach is proposed: improved cycle enumeration and a simplified integer linear programming model. Extensive simulations are performed to study the power consumption of $p$ -cycles under different Traffic patterns in terms of Traffic asymmetry ( $TASY$ ), anycast ratio (AR), and the number of data centers (DCs). The results strongly demonstrate that directed $p$ -cycles obtain significant power savings for protecting asymmetric Traffic in EONs. The power savings rise up to $46.91\%$ and $36.38\%$ compared with undirected $p$ -cycles as the $TASY$ and AR increase, respectively. Moreover, the directed $p$ -cycles achieve valuable power savings (up to $46.1\%$ ) with the introduction of DCs while the amount of power savings does not depend on the number of DCs.

G Swallow - One of the best experts on this subject based on the ideXlab platform.

  • sonet sdh like resilience for ip networks a survey of Traffic Protection mechanisms
    IEEE Network, 2004
    Co-Authors: G Suwala, G Swallow
    Abstract:

    Typically IP networks respond to a link failure by finding an alternate Traffic path after the failure is discovered. This results in a convergence time during which Traffic may be dropped at the failed link until an alternate path is found (e.g., through link state routing protocols like OSPF or IS-IS). While there has been steady progress in decreasing IP routing convergence times, these approaches are limited by the need to communicate among multiple routers. However, IP Traffic can be protected using techniques below layer 3, which are not subject to this constraint. This article discusses mechanisms where a link failure can be protected locally, SONET/SDH-like, at sub-50-ms Protection times. Descriptions of linear SONET automatic Protection switching for routers, resilient packet ring Protection, IP interface bundling, and MPLS fast reroute are covered. Protection triggers and coexistence of various Protection methods are also discussed.

Fen Zhou - One of the best experts on this subject based on the ideXlab platform.

  • power efficient Protection with directed p cycles for asymmetric Traffic in elastic optical networks
    Journal of Lightwave Technology, 2016
    Co-Authors: Fen Zhou, Shilin Xiao, Zuqing Zhu
    Abstract:

    In this paper, we investigate power-efficient directed preconfigured cycles ( $p$ -Cycles) for asymmetric Traffic Protection in elastic optical networks (EONs) against single link failure. Owing to the advantage of distinguishing Traffic amount in two directions, directed $p$ -cycles consume low power by allocating different spectrum slots and modulation formats for each direction. A mixed integer linear programming (MILP) model is formulated to minimize total power consumption, which takes into account directed cycle generation, spectrum allocation, modulation adaptation, and Protection capacity. To increase the scalability, the MILP model is decomposed, and a two-step approach is proposed: improved cycle enumeration and a simplified integer linear programming model. Extensive simulations are performed to study the power consumption of $p$ -cycles under different Traffic patterns in terms of Traffic asymmetry ( $TASY$ ), anycast ratio (AR), and the number of data centers (DCs). The results strongly demonstrate that directed $p$ -cycles obtain significant power savings for protecting asymmetric Traffic in EONs. The power savings rise up to $46.91\%$ and $36.38\%$ compared with undirected $p$ -cycles as the $TASY$ and AR increase, respectively. Moreover, the directed $p$ -cycles achieve valuable power savings (up to $46.1\%$ ) with the introduction of DCs while the amount of power savings does not depend on the number of DCs.

Krzysztof Walkowiak - One of the best experts on this subject based on the ideXlab platform.

  • Different strategies for dynamic multicast Traffic Protection in elastic optical networks
    2016 8th International Workshop on Resilient Networks Design and Modeling (RNDM), 2016
    Co-Authors: Michał Aibin, Krzysztof Walkowiak
    Abstract:

    Growing popularity of content-oriented services is a significant trend observed recently in communication networks. Due to large volumes of Traffic related to these services, the network operators search for new solutions that allow to deliver content to end users in a cost-effective manner. Elastic optical network (EON) is a relatively novel solution for optical networks. The main advantages of EONs compared to traditional wavelength division multiplexing (WDM) optical networks are more efficient use of spectrum resources and support of flexible modulation format conversion. Moreover, there is a strong focus on multicasting, which is perceived as a much better approach for content delivery compared to unicast transmissions. In this paper we concentrate on dynamic multicast routing in survivable EONs. We compare various Protection methods that may be applied to protect multicast sessions in EONs. For this purpose, we adapt two dynamic routing algorithms with additional survivability constraints and the possibility to change the modulation format at the regeneration nodes. Using realistic assumptions on EONs and representative network topologies, a wide range of simulations is run. First, we show the results to indicate advantages and disadvantages of various Protection methods. In addition, we show gain of enabling partial Protection of receivers in multicast trees. The results clearly show that various QoS levels for multicast Protection allow to save optical network resources, thus, accept more incoming Traffic in the network.

Michael Poss - One of the best experts on this subject based on the ideXlab platform.

  • a robust optimization model for affine quadratic flow thinning a Traffic Protection mechanism for networks with variable link capacity
    Networks, 2020
    Co-Authors: Ilya Kalesnikau, Michal Pioro, Michael Poss, Dritan Nace, Artur Tomaszewski
    Abstract:

    Flow thinning (FT) is a Traffic Protection mechanism for communication networks with variable link capacities, for example wireless networks. With FT, end-to-end Traffic demands use dedicated logical tunnels, for example MPLS tunnels, whose nominal capacity is subject to thinning in order to follow fluctuations in link capacities availability. Moreover, instantaneous Traffic of each demand is throttled at its originating node accordingly to the current total capacity available on the demands dedicated tunnels so that the network is always capable of carrying the admitted Traffic. In this paper we deal with efficient, implementable versions of FT, referred to as AFT (affine FT) and QFT (quadratic FT). By deriving appropriate link availability state and path generation algorithms, we show how real-life network dimen-sioning problems for AFT/QFT can be efficiently treated using a proper characterization of the network link availability states. Results of a numerical study illustrate tractability of the cost minimization problems, and assess efficiency of AFT/QFT as compared with other Protection mechanisms.

  • an optimization model for affine flow thinning a Traffic Protection mechanism for fso networks
    2017 9th International Workshop on Resilient Networks Design and Modeling (RNDM), 2017
    Co-Authors: Michal Pioro, Ilya Kalesnikau, Michael Poss
    Abstract:

    Flow thinning (FT) is an active Traffic Protection mechanism destined for communication networks with variable capacity of links, as for example wireless networks. In FT, end-to-end Traffic demands are equipped with dedicated logical tunnels (for example MPLS tunnels) whose maximal capacity is subject to thinning in order to follow the fluctuations of the currently available link capacity. It follows that for each demand the instantaneous Traffic realized between its end nodes must accommodate to the current total capacity available on its dedicated tunnels. In the paper we develop an optimization model for network dimensioning for a potentially implementable variant of FT, the so called General Affine Flow Thinning (GAFT), and present a solution algorithm based on the path generation approach. We derive a relevant pricing problem and present a numerical study that illustrates efficiency of the optimization algorithm, as well as compares the network cost for different variants of the flow thinning mechanism.