The Experts below are selected from a list of 20109 Experts worldwide ranked by ideXlab platform

Bijoy Chand Chatterjee - One of the best experts on this subject based on the ideXlab platform.

  • impairment aware Spectrum Allocation in elastic optical networks a dispersion sensitive approach
    Optical Fiber Technology, 2021
    Co-Authors: Bijoy Chand Chatterjee, Norvald Stol, Eiji Oki
    Abstract:

    Abstract The degradation of quality-of-transmission (QoT) due to the dispersion effect is a critical issue in elastic optical networks (EONs). To satisfy the required quality of transmission, a robust modulation level needs to be adopted. Thus, the number of required slots for Spectrum Allocation is increased. Although dispersion compensation devices reduce the effect of dispersion, they require an additional cost. This paper presents a dispersion-sensitive Spectrum Allocation approach for EONs to suppress the call blocking in the network. The presented Spectrum Allocation approach does not use any dispersion compensating device for suppressing the dispersion effect. It allocates shorter lightpath requests from the largest indexed Spectrum slot, where the effect of dispersion is higher, and longer lightpath requests from the smallest indexed Spectrum slot, where the effect of dispersion is lower. To satisfy the required QoT threshold level for the longer lightpath requests, the presented approach uses a less robust modulation level. Thus, for lightpath establishment, a lower number of Spectrum slots are required. In the presented approach, lightpath requests are separated as longer and shorter lightpath requests using either the predetermined-threshold policy or the lightpath threshold selection algorithm. When the traffic condition is not known in advance, the predetermined-threshold policy is not applicable. In that case, the lightpath threshold selection algorithm is used to find the distance threshold value, which provides the lowest blocking probability. Simulation results indicate that the presented dispersion-sensitive Spectrum Allocation approach outperforms the conventional Spectrum Allocation scheme in terms of available contiguous aligned slot ratio and blocking probability.

  • Performance of routing and Spectrum Allocation approaches for multicast traffic in elastic optical networks
    Optical Fiber Technology, 2020
    Co-Authors: Panchali Datta Choudhury, P.v. Rakesh Reddy, Bijoy Chand Chatterjee, Eiji Oki
    Abstract:

    Abstract In this paper, we investigate routing and Spectrum Allocation (RSA) approaches in elastic optical networks for multicast traffic demands. We consider that a light-tree is constructed for each multicast traffic demand and Spectrum is allocated to this light-tree using the first-fit Spectrum Allocation policy. We present an approximation based Steiner tree approach for RSA (STA-RSA) and compare it with the shortest path tree based routing and Spectrum Allocation (SPT-RSA) to show the benefits of STA-RSA over SPT-RSA. The numerical results show that the presented approach outperforms the traditional approaches in terms of bandwidth blocking probability.

  • holding time and impairment aware shared Spectrum Allocation in mixed line rate elastic optical networks
    IEEE\ OSA Journal of Optical Communications and Networking, 2019
    Co-Authors: Jijun Zhao, Hui Yang, Eiji Oki, Bowen Bao, Bijoy Chand Chatterjee
    Abstract:

    Cross-phase modulation (XPM) is considered one of the key factors for the quality-of-transmission (QoT) degradation in elastic optical networks (EONs) with mixed line rates (MLRs). Based on the XPM consideration, this paper proposes a holding-time- and impairment-aware shared Spectrum Allocation scheme for EONs with MLRs to suppress call blocking in the network. The proposed scheme divides the entire Spectrum resources into three exclusive partitioning zones and two shared partitioning zones; furthermore, two exclusive partitioning zones are separated by one shared partitioning zone. A lightpath request is considered as a longer holding-time lightpath request if the holding time of the request is greater than a specified threshold value defined by the network operator; otherwise, the request is considered a shorter holding-time lightpath request. The proposed scheme assigns shorter holding-time lightpath requests to the exclusive partitioning zones and longer holding-time lightpath requests to the shared partitioning zones. It is observed from simulation results that the proposed scheme outperforms the conventional scheme in terms of blocking probability and QoT estimation.

  • performance evaluation of first last exact fit Spectrum Allocation policy for elastic optical networks
    International Conference on Transparent Optical Networks, 2017
    Co-Authors: Bijoy Chand Chatterjee, Nattapong Kitsuwan, Eiji Oki
    Abstract:

    This paper evaluates the performance of the first-last-exact fit Spectrum Allocation policy for elastic optical networks. The first-last-exact fit Spectrum Allocation policy is intended to increase the number of aligned available slots and avoid small contiguous available slots, and hence suppresses the blocking probability. This policy separates the Allocation of disjoint and non-disjoint connections. Connections with disjoint paths are allocated using the first-exact fit Allocation policy, whereas connections with non-disjoint paths are allocated using the last-exact fit Allocation policy. The separation of the disjoint and non-disjoint connections provides a higher number of aligned available slots. Simulation results show that the first-last-exact fit Spectrum Allocation policy improves the traffic admissibility compared to the conventional first fit and first-last fit policies.

  • a Spectrum Allocation scheme based on first last exact fit policy for elastic optical networks
    Journal of Network and Computer Applications, 2016
    Co-Authors: Bijoy Chand Chatterjee, Waya Fadini, Eiji Oki
    Abstract:

    In elastic optical networks, bandwidth fragmentation refers to the existence of non-aligned and non-contiguous available subcarrier slots in the set of all subcarrier slots. Since Spectrum for a connection must be allocated on contiguous subcarrier slots and aligned along the routing path in the absence of wavelength converter, non-aligned and non-contiguous available subcarrier slots could cause blocking. This paper proposes a Spectrum Allocation scheme based on first-last-exact fit Allocation policy for elastic optical networks in order to increase the number of aligned available slots and avoid small contiguous available slots. The proposed scheme separates the Allocation of disjoint and non-disjoint connections. Connections with disjoint paths are allocated using the first-exact fit Allocation policy, whereas connections with non-disjoint paths are allocated using the last-exact fit Allocation policy. The separation of the disjoint and non-disjoint connections provides a higher number of aligned available slots. The exact fit policy provides a higher number of contiguous available slots. The contiguous aligned available slots reduce the bandwidth fragmentation, and hence the blocking probability is suppressed. Simulation results show that the proposed scheme outperforms the conventional scheme in terms of blocking probability.

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

  • energy efficient cell activation user association and Spectrum Allocation in heterogeneous networks
    IEEE Journal on Selected Areas in Communications, 2016
    Co-Authors: Binnan Zhuang, Michael L. Honig
    Abstract:

    Next generation (5G) cellular networks are expected to be supported by an extensive infrastructure with many-fold increase in the number of cells per unit area compared to today. The total energy consumption of base transceiver stations (BTSs) is an important issue for both economic and environmental reasons. In this paper, an optimization-based framework is proposed for energy-efficient global radio resource management in heterogeneous wireless networks. Specifically, with stochastic arrivals of known rates intended for users, the smallest set of BTSs is activated with jointly optimized user association and Spectrum Allocation to stabilize the network. The average delay is subsequently minimized. The scheme can be carried out periodically on a relatively slow timescale to adapt to aggregate traffic variations and average channel conditions. Numerical results show that the proposed scheme significantly reduces energy consumption and increases quality of service compared to existing schemes.

  • Energy-Efficient Cell Activation, User Association, and Spectrum Allocation in Heterogeneous Networks
    IEEE Journal on Selected Areas in Communications, 2016
    Co-Authors: Binnan Zhuang, Dongning Guo, Michael L. Honig
    Abstract:

    Next generation (5G) cellular networks are expected to be supported by an extensive infrastructure with many-fold increase in the number of cells per unit area compared to today. The total energy consumption of base transceiver stations (BTSs) is an important issue for both economic and environmental reasons. In this paper, an optimization-based framework is proposed for energy-efficient global radio resource management in heterogeneous wireless networks. Specifically, with stochastic arrivals of known rates intended for users, the smallest set of BTSs is activated with jointly optimized user association and Spectrum Allocation to stabilize the network first and then minimize the delay. The scheme can be carried out periodically on a relatively slow timescale to adapt to aggregate traffic variations and average channel conditions. Numerical results show that the proposed scheme significantly reduces the energy consumption and increases the quality of service compared to existing schemes in the literature.

Eiji Oki - One of the best experts on this subject based on the ideXlab platform.

  • impairment aware Spectrum Allocation in elastic optical networks a dispersion sensitive approach
    Optical Fiber Technology, 2021
    Co-Authors: Bijoy Chand Chatterjee, Norvald Stol, Eiji Oki
    Abstract:

    Abstract The degradation of quality-of-transmission (QoT) due to the dispersion effect is a critical issue in elastic optical networks (EONs). To satisfy the required quality of transmission, a robust modulation level needs to be adopted. Thus, the number of required slots for Spectrum Allocation is increased. Although dispersion compensation devices reduce the effect of dispersion, they require an additional cost. This paper presents a dispersion-sensitive Spectrum Allocation approach for EONs to suppress the call blocking in the network. The presented Spectrum Allocation approach does not use any dispersion compensating device for suppressing the dispersion effect. It allocates shorter lightpath requests from the largest indexed Spectrum slot, where the effect of dispersion is higher, and longer lightpath requests from the smallest indexed Spectrum slot, where the effect of dispersion is lower. To satisfy the required QoT threshold level for the longer lightpath requests, the presented approach uses a less robust modulation level. Thus, for lightpath establishment, a lower number of Spectrum slots are required. In the presented approach, lightpath requests are separated as longer and shorter lightpath requests using either the predetermined-threshold policy or the lightpath threshold selection algorithm. When the traffic condition is not known in advance, the predetermined-threshold policy is not applicable. In that case, the lightpath threshold selection algorithm is used to find the distance threshold value, which provides the lowest blocking probability. Simulation results indicate that the presented dispersion-sensitive Spectrum Allocation approach outperforms the conventional Spectrum Allocation scheme in terms of available contiguous aligned slot ratio and blocking probability.

  • Performance of routing and Spectrum Allocation approaches for multicast traffic in elastic optical networks
    Optical Fiber Technology, 2020
    Co-Authors: Panchali Datta Choudhury, P.v. Rakesh Reddy, Bijoy Chand Chatterjee, Eiji Oki
    Abstract:

    Abstract In this paper, we investigate routing and Spectrum Allocation (RSA) approaches in elastic optical networks for multicast traffic demands. We consider that a light-tree is constructed for each multicast traffic demand and Spectrum is allocated to this light-tree using the first-fit Spectrum Allocation policy. We present an approximation based Steiner tree approach for RSA (STA-RSA) and compare it with the shortest path tree based routing and Spectrum Allocation (SPT-RSA) to show the benefits of STA-RSA over SPT-RSA. The numerical results show that the presented approach outperforms the traditional approaches in terms of bandwidth blocking probability.

  • holding time and impairment aware shared Spectrum Allocation in mixed line rate elastic optical networks
    IEEE\ OSA Journal of Optical Communications and Networking, 2019
    Co-Authors: Jijun Zhao, Hui Yang, Eiji Oki, Bowen Bao, Bijoy Chand Chatterjee
    Abstract:

    Cross-phase modulation (XPM) is considered one of the key factors for the quality-of-transmission (QoT) degradation in elastic optical networks (EONs) with mixed line rates (MLRs). Based on the XPM consideration, this paper proposes a holding-time- and impairment-aware shared Spectrum Allocation scheme for EONs with MLRs to suppress call blocking in the network. The proposed scheme divides the entire Spectrum resources into three exclusive partitioning zones and two shared partitioning zones; furthermore, two exclusive partitioning zones are separated by one shared partitioning zone. A lightpath request is considered as a longer holding-time lightpath request if the holding time of the request is greater than a specified threshold value defined by the network operator; otherwise, the request is considered a shorter holding-time lightpath request. The proposed scheme assigns shorter holding-time lightpath requests to the exclusive partitioning zones and longer holding-time lightpath requests to the shared partitioning zones. It is observed from simulation results that the proposed scheme outperforms the conventional scheme in terms of blocking probability and QoT estimation.

  • performance evaluation of first last exact fit Spectrum Allocation policy for elastic optical networks
    International Conference on Transparent Optical Networks, 2017
    Co-Authors: Bijoy Chand Chatterjee, Nattapong Kitsuwan, Eiji Oki
    Abstract:

    This paper evaluates the performance of the first-last-exact fit Spectrum Allocation policy for elastic optical networks. The first-last-exact fit Spectrum Allocation policy is intended to increase the number of aligned available slots and avoid small contiguous available slots, and hence suppresses the blocking probability. This policy separates the Allocation of disjoint and non-disjoint connections. Connections with disjoint paths are allocated using the first-exact fit Allocation policy, whereas connections with non-disjoint paths are allocated using the last-exact fit Allocation policy. The separation of the disjoint and non-disjoint connections provides a higher number of aligned available slots. Simulation results show that the first-last-exact fit Spectrum Allocation policy improves the traffic admissibility compared to the conventional first fit and first-last fit policies.

  • a Spectrum Allocation scheme based on first last exact fit policy for elastic optical networks
    Journal of Network and Computer Applications, 2016
    Co-Authors: Bijoy Chand Chatterjee, Waya Fadini, Eiji Oki
    Abstract:

    In elastic optical networks, bandwidth fragmentation refers to the existence of non-aligned and non-contiguous available subcarrier slots in the set of all subcarrier slots. Since Spectrum for a connection must be allocated on contiguous subcarrier slots and aligned along the routing path in the absence of wavelength converter, non-aligned and non-contiguous available subcarrier slots could cause blocking. This paper proposes a Spectrum Allocation scheme based on first-last-exact fit Allocation policy for elastic optical networks in order to increase the number of aligned available slots and avoid small contiguous available slots. The proposed scheme separates the Allocation of disjoint and non-disjoint connections. Connections with disjoint paths are allocated using the first-exact fit Allocation policy, whereas connections with non-disjoint paths are allocated using the last-exact fit Allocation policy. The separation of the disjoint and non-disjoint connections provides a higher number of aligned available slots. The exact fit policy provides a higher number of contiguous available slots. The contiguous aligned available slots reduce the bandwidth fragmentation, and hence the blocking probability is suppressed. Simulation results show that the proposed scheme outperforms the conventional scheme in terms of blocking probability.

Binnan Zhuang - One of the best experts on this subject based on the ideXlab platform.

  • energy efficient cell activation user association and Spectrum Allocation in heterogeneous networks
    IEEE Journal on Selected Areas in Communications, 2016
    Co-Authors: Binnan Zhuang, Michael L. Honig
    Abstract:

    Next generation (5G) cellular networks are expected to be supported by an extensive infrastructure with many-fold increase in the number of cells per unit area compared to today. The total energy consumption of base transceiver stations (BTSs) is an important issue for both economic and environmental reasons. In this paper, an optimization-based framework is proposed for energy-efficient global radio resource management in heterogeneous wireless networks. Specifically, with stochastic arrivals of known rates intended for users, the smallest set of BTSs is activated with jointly optimized user association and Spectrum Allocation to stabilize the network. The average delay is subsequently minimized. The scheme can be carried out periodically on a relatively slow timescale to adapt to aggregate traffic variations and average channel conditions. Numerical results show that the proposed scheme significantly reduces energy consumption and increases quality of service compared to existing schemes.

  • Energy-Efficient Cell Activation, User Association, and Spectrum Allocation in Heterogeneous Networks
    IEEE Journal on Selected Areas in Communications, 2016
    Co-Authors: Binnan Zhuang, Dongning Guo, Michael L. Honig
    Abstract:

    Next generation (5G) cellular networks are expected to be supported by an extensive infrastructure with many-fold increase in the number of cells per unit area compared to today. The total energy consumption of base transceiver stations (BTSs) is an important issue for both economic and environmental reasons. In this paper, an optimization-based framework is proposed for energy-efficient global radio resource management in heterogeneous wireless networks. Specifically, with stochastic arrivals of known rates intended for users, the smallest set of BTSs is activated with jointly optimized user association and Spectrum Allocation to stabilize the network first and then minimize the delay. The scheme can be carried out periodically on a relatively slow timescale to adapt to aggregate traffic variations and average channel conditions. Numerical results show that the proposed scheme significantly reduces the energy consumption and increases the quality of service compared to existing schemes in the literature.

Miroslaw Klinkowski - One of the best experts on this subject based on the ideXlab platform.

  • routing and Spectrum Allocation algorithms for elastic optical networks with dedicated path protection
    Optical Switching and Networking, 2014
    Co-Authors: Krzysztof Walkowiak, Miroslaw Klinkowski, Bartosz Rabiega, Roza Gościen
    Abstract:

    Abstract Elastic optical network (EON) architectures have been recently proposed as a candidate solution for provisioning of both huge bandwidth and flexible connections in next generation optical networks. In this paper, we focus on survivable EON scenarios and, in particular, we address an offline problem of routing and Spectrum Allocation (RSA) with dedicated path protection (DPP) in EON. We formulate RSA/DPP as an Integer Linear Programming (ILP) problem. Since RSA is a difficult problem itself, we propose to apply a metaheuristic approach to provide near-optimal solutions to RSA/DPP. Namely, we develop a Tabu Search-based algorithm (TS), and a hybrid Adaptive Frequency Assignment-TS (AFA/TS) algorithm. We investigate the efficiency of the algorithms for a set of network and DPP scenarios and we show that the proposed algorithms outperform other reference algorithms. Eventually, we present some comparative results for different path protection scenarios.

  • a tabu search algorithm for routing and Spectrum Allocation in elastic optical networks
    International Conference on Transparent Optical Networks, 2014
    Co-Authors: Roza Goscien, Miroslaw Klinkowski, Krzysztof Walkowiak
    Abstract:

    In this paper we present a tabu search-based algorithm, which is dedicated to solving the routing and Spectrum Allocation problem in elastic optical networks. To evaluate performance of the proposed method, we carry a number of experiments on realistic network topologies. We compare our method with both optimal results yielded by the CPLEX solver and results obtained by heuristic algorithms that were proposed in the literature for the same optimization problem. The findings of our investigation show that the proposed tabu search method provides the solutions close to optimal ones and it significantly outperforms the reference methods.

  • Elastic Spectrum Allocation for time-varying traffic in flexgrid optical networks
    IEEE Journal on Selected Areas in Communications, 2013
    Co-Authors: Miroslaw Klinkowski, Davide Careglio, Luis Velasco, Marc Ruiz, Victor Lopez, Jaume Comellas
    Abstract:

    Elastic flexgrid optical networks (FG-ON) are considered a very promising solution for next-generation optical networks. In this article we focus on lightpath adaptation under variable traffic demands in FG-ON. Specifically, we explore the elastic Spectrum Allocation (SA) capability of FG-ON and, in this context, we study the effectiveness of three alternative SA schemes in terms of the network performance. To this end, we formulate a Multi-Hour Routing and Spectrum Allocation (MH-RSA) optimization problem and solve it by means of both Integer Linear Programming (ILP) and efficient heuristic algorithms. Since, as numerical results show, the effectiveness of SA schemes highly depends on the traffic demand profile, we formulate some indications on the applicability of elastic SA in FG-ON.

  • Modeling the routing and Spectrum Allocation problem for flexgrid optical networks
    Photonic Network Communications, 2012
    Co-Authors: Luis Velasco, Miroslaw Klinkowski, Marc Ruiz, Jaume Comellas
    Abstract:

    Flexgrid optical networks are attracting huge interest due to their higher Spectrum efficiency and flexibility in comparison with traditional wavelength switched optical networks based on the wavelength division multiplexing technology. To properly analyze, design, plan, and operate flexible and elastic networks, efficient methods are required for the routing and Spectrum Allocation (RSA) problem. Specifically, the allocated spectral resources must be, in absence of Spectrum converters, the same along the links in the route (the continuity constraint) and contiguous in the Spectrum (the contiguity constraint). In light of the fact that the contiguity constraint adds huge complexity to the RSA problem, we introduce the concept of channels for the representation of contiguous spectral resources. In this paper, we show that the use of a pre-computed set of channels allows considerably reducing the problem complexity. In our study, we address an off-line RSA problem in which enough Spectrum needs to be allocated for each demand of a given traffic matrix. To this end, we present novel integer lineal programming (ILP) formulations of RSA that are based on the assignment of channels. The evaluation results reveal that the proposed approach allows solving the RSA problem much more efficiently than previously proposed ILP-based methods and it can be applied even for realistic problem instances, contrary to previous ILP formulations.

  • elastic Spectrum Allocation for variable traffic in flexible grid optical networks
    Optical Fiber Communication Conference, 2012
    Co-Authors: Luis Velasco, Miroslaw Klinkowski, Marc Ruiz, Victor Lopez, G Junyent
    Abstract:

    We focus on lightpath adaptation under variable traffic demands in flexible-grid optical networks. Specifically, we study three different adaptation schemes for the variable Spectrum Allocation. Illustrative numerical results show the benefits of the schemes.