The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform

Sungchang Lee - One of the best experts on this subject based on the ideXlab platform.

  • Overview of the Multicast Route selection criteria and opportunistic Routes.
    2018
    Co-Authors: Ghulam Sarwar, Sungchang Lee
    Abstract:

    Overview of the Multicast Route selection criteria and opportunistic Routes.

  • on dynamic Multicast trees for stormless binding update in network mobility
    International Conference on Computational Science and Its Applications, 2007
    Co-Authors: Moonseong Kim, Sungchang Lee
    Abstract:

    Mobile IP (MIP) is designed for supporting mobile nodes. The technology does not sufficiently handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) [1] ensures session continuity for all the nodes in a MObile NETwork (MONET). Since the protocol is based on MIP, when used to support Multicast for NEMO, it inherits the same fundamental problems as MIP, such as tunnel convergence. Recently, Prefix Delegation (PD)-based Multicast [2] has been proposed for the Multicast Route Optimization (RO) scheme in NEMO. However, the Binding Update (BU) storm is generated by PD-based Multicast, whenever an MR migrates to a new foreign network. In this paper, hence, we propose the Multicast RO scheme with stormless BU in NEMO environments.

  • ICCSA (2) - On dynamic Multicast trees for stormless binding update in network mobility
    Lecture Notes in Computer Science, 1
    Co-Authors: Moonseong Kim, Sungchang Lee
    Abstract:

    Mobile IP (MIP) is designed for supporting mobile nodes. The technology does not sufficiently handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) [1] ensures session continuity for all the nodes in a MObile NETwork (MONET). Since the protocol is based on MIP, when used to support Multicast for NEMO, it inherits the same fundamental problems as MIP, such as tunnel convergence. Recently, Prefix Delegation (PD)-based Multicast [2] has been proposed for the Multicast Route Optimization (RO) scheme in NEMO. However, the Binding Update (BU) storm is generated by PD-based Multicast, whenever an MR migrates to a new foreign network. In this paper, hence, we propose the Multicast RO scheme with stormless BU in NEMO environments.

Mohammad Reza Meybodi - One of the best experts on this subject based on the ideXlab platform.

  • Weighted Steiner Connected Dominating Set and its Application to Multicast Routing in Wireless MANETs
    Wireless Personal Communications, 2011
    Co-Authors: Javad Akbari Torkestani, Mohammad Reza Meybodi
    Abstract:

    In this paper, we first propose three centralized learning automata-based heuristic algorithms for approximating a near optimal solution to the minimum weight Steiner connected dominating set (WSCDS) problem. Finding the Steiner connected dominating set of the network graph is a promising approach for Multicast routing in wireless ad-hoc networks. Therefore, we present a distributed implementation of the last approximation algorithm proposed in this paper (Algorithm III) for Multicast routing in wireless mobile ad-hoc networks. The proposed WSCDS algorithms are compared with the well-known existing algorithms and the obtained results show that Algorithm III outperforms the others both in terms of the dominating set size and running time. Our simulation experiments also show the superiority of the proposed Multicast routing algorithm over the best previous methods in terms of the packet delivery ratio, Multicast Route lifetime, and end-to-end delay.

  • a link stability based Multicast routing protocol for wireless mobile ad hoc networks
    Journal of Network and Computer Applications, 2011
    Co-Authors: Javad Akbari Torkestani, Mohammad Reza Meybodi
    Abstract:

    Recently, several studies have been conducted to design mobility-based Multicast routing protocols for wireless mobile ad hoc networks (MANET). These protocols assume that the mobility parameters of the network are fixed, and so they cannot perform well under real MANET scenarios in which the mobility parameters of the hosts vary over time at random. Finding the optimal solution to the Multicast routing problem is incredibly hard, if the mobility parameters are assumed to be random variables. This becomes more difficult when the probability distribution function of these random variables is assumed to be unknown. In this paper, we propose a weighted Multicast routing algorithm for MANET in which the mobility parameters are supposed to be random variables with unknown distribution. In this method, the Multicast routing problem is first transformed into an equivalent stochastic Steiner tree problem in which the random weight associated with a communication link is its expected duration time. Then, a learning automata-based algorithm is proposed for solving the proxy Steiner tree problem. The aim of the proposed algorithm is to find the most stable Multicast Route (with the maximum duration) against the host mobility. Experimental results confirm the superiority of the proposed method over the best existing mobility-based Multicast routing protocols in terms of the packet delivery ratio, Multicast Route lifetime, control message overhead, and end-to-end delay.

  • mobility based Multicast routing algorithm for wireless mobile ad hoc networks a learning automata approach
    Computer Communications, 2010
    Co-Authors: Javad Akbari Torkestani, Mohammad Reza Meybodi
    Abstract:

    During the last decades, many studies have been conducted on Multicast routing in mobile ad hoc networks (MANET) and a host of algorithms have been proposed. In existing algorithms, the mobility characteristics are assumed to be constant, and so they do not scale well when the mobility parameters are not deterministic. To the best of our knowledge no work has been done on Multicast routing when the mobility parameters are stochastic, while in realistic applications these parameters vary with time. In this paper, we propose a mobility-based Multicast routing algorithm for wireless MANETs wherein the mobility characteristics are stochastic and unknown. The proposed algorithm estimates the expected relative mobility of each host, by sampling its movement parameters in various epochs, to realistically predict its motion behavior, and takes advantage of the Steiner connected dominating set to form the virtual Multicast backbone. To do this, in this paper, a stochastic version of the minimum Steiner connected dominating set problem in weighted network graphs, where the relative mobility of each host is considered as its weight is initially introduced. Then, a distributed learning automata-based algorithm is designed to solve this problem. The designed algorithm is proposed for Multicast routing in wireless mobile Ad-hoc networks. The experiments show the superiority of the proposed Multicast routing algorithm over the existing methods in terms of the packet delivery ratio, Multicast Route lifetime, and end-to-end delay. We present a strong convergence theorem in which the convergence of the proposed distributed learning automata-based algorithm to the optimal solution is proved. It is shown that the most stable Multicast Route is found with a probability as close as to unity by the proper choice of the parameters of the distributed learning automata.

Miklós Molnár - One of the best experts on this subject based on the ideXlab platform.

  • Multicast routing from a set of data centers in elastic optical networks
    Optical Switching and Networking, 2019
    Co-Authors: Miklós Molnár, Jordi Perelló, Josep Solé-pareta, Conor Mcardle
    Abstract:

    This paper introduces the Multi-Server Multicast (MSM) approach for Content Delivery Networks (CDNs) delivering services offered by a set of Data Centers (DCs). All DCs offer the same services. The network is an Elastic Optical Network (EON) and for a good performance, routing is performed directly at the optical layer. Optical switches have heterogeneous capacities, that is, light splitting is not available in all switches. Moreover, frequency slot conversion is not possible in any of them. We account for the degradation that optical signals suffer both in the splitting nodes, as well as across fiber links to compute their transmission reach. The optimal solution of the MSM is a set of light-hierarchies. This Multicast Route contains a light trail from one of the DCs to each of the destinations with respect to the optical constraints while optimizing an objective (e.g., minimizing a function). Finding such a structure is often an NP-hard problem. The light-hierarchies initiated from different DCs permit delivering the Multicast session to all end-users with a better utilization of the optical resources, while also reducing Multicast session latencies, as contents can be delivered from such DCs closer to end-users. We propose an Integer Linear Programming (ILP) formulation to optimally decide on which light-hierarchies should be setup. Simulation results illustrate the benefits of MSM in two reference backbone networks.

  • ILP formulation of the exact solution of multi-constrained minimum cost Multicast
    Computer Networks, 2018
    Co-Authors: Walid Khallef, Sylvain Durand, Miklós Molnár
    Abstract:

    Multimedia applications such as videoconferencing and collaborative applications require the satisfaction of several Quality of Service constraints (QoS). The routing with respect to QoS constraints was proposed in order to satisfy the user requirement and guarantee a certain level of performance to a data flow. As the communication architecture of these applications is often Multicasting, the problem of finding a Multicast Route satisfying the QoS constraints proves to be challenging. In this paper we propose an Integer Linear Program (ILP) for finding the Multicast Route respecting a set of QoS constraints with minimum cost. Since the problem is NP-hard, we propose an efficient pretreatment algorithm (ArcReduce) to accelerate the resolution time. The pretreatment process can even answer in polynomial time, whether the problem has a solution or not, before starting the resolution process. The computation of the exact solution also allows for comparison of the heuristic solutions to the exact solution. We conduct an analysis of the ILP and the ArcReduce with various sizes of input data regarding the execution time, the success rate and the quality of the generated Multicast Route.

  • Exact Algorithm to Solve the Minimum Cost Multi-Constrained Multicast Routing Problem
    Journal of Computer and Communications, 2016
    Co-Authors: Miklós Molnár
    Abstract:

    The optimal solution of the multi-constrained QoS Multicast routing problem is a tree-like hierarchical structure in the topology graph. This Multicast Route contains a feasible path from the source node to each of the destinations with respect to a set of QoS constraints while minimizing a cost function. Often, it is a tree. In other cases, the hierarchies can return several times to nodes and links of the topology graph. Similarly to Steiner problem, finding such a structure is an NP-hard problem. The usual tree and topology enumeration algorithms applied for the Steiner problem cannot be used to solve the addressed problem. In this paper, we propose an exact algorithm based on the Branch and Bound principle and improved by the Lookahead technique. We show relevant properties of the optimum hierarchy permitting efficient pruning of the search space. To our knowledge, our paper is the first to propose an exact algorithm for this non-trivial multi-constrained optimal Multicast Route computation. Simulations illustrate the efficiency of the proposed pruning operations. The analysis of the execution time shows that in simple topologies and with tight QoS constraints the exact algorithm requires relatively little execution time. With loose constraints the computation time cannot be tolerated even for off-line Route computation. In these cases, the solution is close to a Steiner tree and heuristics can be applied. These results can serve as basis for the design of efficient, polynomial-time routing algorithms.

  • The cost optimal solution of the multi-constrained Multicast routing problem
    Computer Networks, 2012
    Co-Authors: Miklós Molnár, Alia Bellabas, Samer Lahoud
    Abstract:

    In this paper, we define the cost optimal solution of the multi-constrained Multicast routing problem. This problem consists in finding a Multicast structure that spans a source node and a set of destinations with respect to a set of constraints, while minimizing a cost function. This optimization is particularly interesting for Multicast network communications that require Quality of Service (QoS) guarantees. Finding such a structure that satisfies the set of constraints is an NP-hard problem. To solve the addressed routing problem, most of the proposed algorithms focus on Multicast trees. In some cases, the optimal spanning structure (i.e. the optimal Multicast Route) is neither a tree nor a set of trees nor a set of optimal QoS paths. The main result of our study is the exact identification of this optimal solution. We demonstrate that the optimal connected partial spanning structure that solves the multi-constrained Multicast routing problem always corresponds to a hierarchy, a recently proposed generalization of the tree concept. We define the directed partial minimum spanning hierarchies as optimal solutions for the multi-constrained Multicast routing problem and analyze their relevant properties. To our knowledge, our paper is the first study that exactly describes the cost optimal solution of this NP-hard problem.

Molnár Miklós - One of the best experts on this subject based on the ideXlab platform.

  • Multicast routing from a set of data centers in elastic optical networks
    'Elsevier BV', 2019
    Co-Authors: Molnár Miklós, Le, Dinh Danh, Perelló Muntan Jordi, Solé Pareta Josep, Mcardle Conor
    Abstract:

    This paper introduces the Multi-Server Multicast (MSM) approach for Content Delivery Networks (CDNs) delivering services offered by a set of Data Centers (DCs). All DCs offer the same services. The network is an Elastic Optical Network (EON) and for a good performance, routing is performed directly at the optical layer. Optical switches have heterogeneous capacities, that is, light splitting is not available in all switches. Moreover, frequency slot conversion is not possible in any of them. We account for the degradation that optical signals suffer both in the splitting nodes, as well as across fiber links to compute their transmission reach. The optimal solution of the MSM is a set of light-hierarchies. This Multicast Route contains a light trail from one of the DCs to each of the destinations with respect to the optical constraints while optimizing an objective (e.g., minimizing a function). Finding such a structure is often an NP-hard problem. The light-hierarchies initiated from different DCs permit delivering the Multicast session to all end-users with a better utilization of the optical resources, while also reducing Multicast session latencies, as contents can be delivered from such DCs closer to end-users. We propose an Integer Linear Programming (ILP) formulation to optimally decide on which light-hierarchies should be setup. Simulation results illustrate the benefits of MSM in two reference backbone networks.Peer Reviewe

  • Multicast routing from a set of data centers in elastic optical networks
    'Elsevier BV', 2019
    Co-Authors: Molnár Miklós, Le, Dinh Danh, Solé Pareta Josep, Perelló Jordi, Mcardle Conor
    Abstract:

    International audienceThis paper introduces the Multi-Server Multicast (MSM) approach for Content Delivery Networks (CDNs) delivering services offered by a set of Data Centers (DCs). All DCs offer the same services. The network is an Elastic Optical Network (EON) and for a good performance, routing is performed directly at the optical layer. Optical switches have heterogeneous capacities, that is, light splitting is not available in all switches. Moreover, frequency slot conversion is not possible in any of them. We account for the degradation that optical signals suffer both in the splitting nodes, as well as across fiber links to compute their transmission reach. The optimal solution of the MSM is a set of light-hierarchies. This Multicast Route contains a light trail from one of the DCs to each of the destinations with respect to the optical constraints while optimizing an objective (e.g., minimizing a function). Finding such a structure is often an NP-hard problem. The light-hierarchies initiated from different DCs permit delivering the Multicast session to all end-users with a better utilization of the optical resources, while also reducing Multicast session latencies, as contents can be delivered from such DCs closer to end-users. We propose an Integer Linear Programming (ILP) formulation to optimally decide on which light-hierarchies should be setup. Simulation results illustrate the benefits of MSM in two reference backbone networks

  • ILP formulation of the exact solution of multi-constrained minimum cost Multicast
    'Elsevier BV', 2018
    Co-Authors: Khallef Walid, Durand Sylvain, Molnár Miklós
    Abstract:

    International audienceMultimedia applications such as videoconferencing and collaborative applications require the satisfaction of several Quality of Service constraints (QoS). The routing with respect to QoS constraints was proposed in order to satisfy the user requirement and guarantee a certain level of performance to a data flow. As the communication architecture of these applications is often Multicasting, the problem of finding a Multicast Route satisfying the QoS constraints proves to be challenging. In this paper we propose an Integer Linear Program (ILP) for finding the Multicast Route respecting a set of QoS constraints with minimum cost. Since the problem is NP-hard, we propose an efficient pretreatment algorithm (ArcReduce) to accelerate the resolution time. The pretreatment process can even answer in polynomial time, whether the problem has a solution or not, before starting the resolution process. The computation of the exact solution also allows for comparison of the heuristic solutions to the exact solution. We conduct an analysis of the ILP and the ArcReduce with various sizes of input data regarding the execution time, the success rate and the quality of the generated Multicast Route

  • Light-Hierarchies: Optimal Multicast Routes under Optical Constraints
    2016
    Co-Authors: Cousin Bernard, Molnár Miklós, Zhou Feng
    Abstract:

    Multicast routing in all optical WDM networks where the light splitting capacity of some optical switches is limited is an important problem. The computation problem of the minimum cost Multicast Routes under optical constraints is NP-difficult. To solve the optimal Multicast routing problem under physical constraints, we propose a new routing structure called 'light-hierarchy''. In a light-hierarchy, the Multicast Route can traverse the same optical switch several times using the same wavelength. This new routing structure may improve both the cost of the optical structures and the throughput on WDM Multicast networks.

  • Exact Algorithm to Solve the Minimum Cost Multi-Constrained Multicast Routing Problem
    'Scientific Research Publishing Inc.', 2016
    Co-Authors: Molnár Miklós
    Abstract:

    International audienceThe optimal solution of the multi-constrained QoS Multicast routing problem is a tree-like hierarchical structure in the topology graph. This Multicast Route contains a feasible path from the source node to each of the destinations with respect to a set of QoS constraints while minimizing a cost function. Often, it is a tree. In other cases, the hierarchies can return several times to nodes and links of the topology graph. Similarly to Steiner problem, finding such a structure is an NP-hard problem. The usual tree and topology enumeration algorithms applied for the Steiner problem cannot be used to solve the addressed problem. In this paper, we propose an exact algorithm based on the Branch and Bound principle and improved by the Lookahead technique. We show relevant properties of the optimum hierarchy permitting efficient pruning of the search space. To our knowledge, our paper is the first to propose an exact algorithm for this non-trivial multi-constrained optimal Multicast Route computation. Simulations illustrate the efficiency of the proposed pruning operations. The analysis of the execution time shows that in simple topologies and with tight QoS constraints the exact algorithm requires relatively little execution time. With loose constraints the computation time cannot be tolerated even for off-line Route computation. In these cases, the solution is close to a Steiner tree and heuristics can be applied. These results can serve as basis for the design of efficient, polynomial-time routing algorithms

Moonseong Kim - One of the best experts on this subject based on the ideXlab platform.

  • on dynamic Multicast trees for stormless binding update in network mobility
    International Conference on Computational Science and Its Applications, 2007
    Co-Authors: Moonseong Kim, Sungchang Lee
    Abstract:

    Mobile IP (MIP) is designed for supporting mobile nodes. The technology does not sufficiently handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) [1] ensures session continuity for all the nodes in a MObile NETwork (MONET). Since the protocol is based on MIP, when used to support Multicast for NEMO, it inherits the same fundamental problems as MIP, such as tunnel convergence. Recently, Prefix Delegation (PD)-based Multicast [2] has been proposed for the Multicast Route Optimization (RO) scheme in NEMO. However, the Binding Update (BU) storm is generated by PD-based Multicast, whenever an MR migrates to a new foreign network. In this paper, hence, we propose the Multicast RO scheme with stormless BU in NEMO environments.

  • ICCSA (2) - On dynamic Multicast trees for stormless binding update in network mobility
    Lecture Notes in Computer Science, 1
    Co-Authors: Moonseong Kim, Sungchang Lee
    Abstract:

    Mobile IP (MIP) is designed for supporting mobile nodes. The technology does not sufficiently handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) [1] ensures session continuity for all the nodes in a MObile NETwork (MONET). Since the protocol is based on MIP, when used to support Multicast for NEMO, it inherits the same fundamental problems as MIP, such as tunnel convergence. Recently, Prefix Delegation (PD)-based Multicast [2] has been proposed for the Multicast Route Optimization (RO) scheme in NEMO. However, the Binding Update (BU) storm is generated by PD-based Multicast, whenever an MR migrates to a new foreign network. In this paper, hence, we propose the Multicast RO scheme with stormless BU in NEMO environments.