The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform

Uri Pincas - One of the best experts on this subject based on the ideXlab platform.

  • Virtual path layouts optimizing total Hop Count on ATM tree networks
    Journal of Discrete Algorithms, 2005
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    Abstract This paper presents some algorithmic results concerning virtual path layouts for the one-to-many communication problem in ATM tree networks. The ATM network model is based on covering the network with a layout of virtual paths, under some constraints on the allowed load, namely, the number of paths that can share an edge. The quality measure used is the Hop Count, namely, the number of edges traversed between two vertices that need to communicate. Whereas most former results concerned the Maximum Hop Count of the virtual path layout, our interest here is in measuring its total Hop Count, or alternatively its average Hop Count. The paper presents a dynamic programming algorithm for planning ATM network layouts with minimal total Hop Count for one-to-many requirements under load constraints over the class of tree networks.

  • the average Hop Count measure for virtual path layouts
    International Symposium on Distributed Computing, 2001
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    This paper studies the average Hop Count measure for virtual path layouts of ATM and optical networks. Routing in the ATM and optical network models is based on covering the network with simple virtual paths, under some constraints on the allowed load (i.e., the number of paths that can share an edge). The Hop Count is the number of edges along the virtual path.Two basic results are established concerning the average Hop Count parameter. The first concerns comparing the Maximum and average Hop Count measures assuming uniform all-to-all communication requirements. We develop a rather general connection between the two measures for virtual path layouts with bounded Maximum load. This connection allows us to extend known lower bounds on the Maximum Hop Count into ones on the average Hop Count for network families satisfying certain conditions, termed non-condensingly contractable (NCC) graph families. Using this characterization, we establish tight lower bounds on the average Hop Count of virtual path layouts with bounded Maximum load for paths, cycles, and trees.Our second result is an algorithm for designing a virtual path layout of minimum average Hop Count for a given tree network with general (weighted) one-to-all requirements.

  • DISC - The Average Hop Count Measure for Virtual Path Layouts
    Lecture Notes in Computer Science, 2001
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    This paper studies the average Hop Count measure for virtual path layouts of ATM and optical networks. Routing in the ATM and optical network models is based on covering the network with simple virtual paths, under some constraints on the allowed load (i.e., the number of paths that can share an edge). The Hop Count is the number of edges along the virtual path.Two basic results are established concerning the average Hop Count parameter. The first concerns comparing the Maximum and average Hop Count measures assuming uniform all-to-all communication requirements. We develop a rather general connection between the two measures for virtual path layouts with bounded Maximum load. This connection allows us to extend known lower bounds on the Maximum Hop Count into ones on the average Hop Count for network families satisfying certain conditions, termed non-condensingly contractable (NCC) graph families. Using this characterization, we establish tight lower bounds on the average Hop Count of virtual path layouts with bounded Maximum load for paths, cycles, and trees.Our second result is an algorithm for designing a virtual path layout of minimum average Hop Count for a given tree network with general (weighted) one-to-all requirements.

David Peleg - One of the best experts on this subject based on the ideXlab platform.

  • Virtual path layouts optimizing total Hop Count on ATM tree networks
    Journal of Discrete Algorithms, 2005
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    Abstract This paper presents some algorithmic results concerning virtual path layouts for the one-to-many communication problem in ATM tree networks. The ATM network model is based on covering the network with a layout of virtual paths, under some constraints on the allowed load, namely, the number of paths that can share an edge. The quality measure used is the Hop Count, namely, the number of edges traversed between two vertices that need to communicate. Whereas most former results concerned the Maximum Hop Count of the virtual path layout, our interest here is in measuring its total Hop Count, or alternatively its average Hop Count. The paper presents a dynamic programming algorithm for planning ATM network layouts with minimal total Hop Count for one-to-many requirements under load constraints over the class of tree networks.

  • DISC - Directed virtual path layouts in ATM networks
    Theoretical Computer Science, 2003
    Co-Authors: Jean-claude Bermond, David Peleg, Nausica Marlin, Stéphane Pérennes
    Abstract:

    Motivated by asynchronous transfer mode in telecommunication networks, we investigate the problem of designing a directed virtual topology on a directed physical topology, which consists in finding a set of directed virtual paths (VPs) satisfying some constraints in terms of load (the number of VPs sharing a physical link) and Hop Count (the number of VPs used to establish a connection). For both general and particular networks, such as paths, cycles, meshes, tori and trees, we derive tight bounds on the virtual diameter (the Maximum Hop Count for a connection) as a function of the network capacity (the Maximum load of a physical link).

  • the average Hop Count measure for virtual path layouts
    International Symposium on Distributed Computing, 2001
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    This paper studies the average Hop Count measure for virtual path layouts of ATM and optical networks. Routing in the ATM and optical network models is based on covering the network with simple virtual paths, under some constraints on the allowed load (i.e., the number of paths that can share an edge). The Hop Count is the number of edges along the virtual path.Two basic results are established concerning the average Hop Count parameter. The first concerns comparing the Maximum and average Hop Count measures assuming uniform all-to-all communication requirements. We develop a rather general connection between the two measures for virtual path layouts with bounded Maximum load. This connection allows us to extend known lower bounds on the Maximum Hop Count into ones on the average Hop Count for network families satisfying certain conditions, termed non-condensingly contractable (NCC) graph families. Using this characterization, we establish tight lower bounds on the average Hop Count of virtual path layouts with bounded Maximum load for paths, cycles, and trees.Our second result is an algorithm for designing a virtual path layout of minimum average Hop Count for a given tree network with general (weighted) one-to-all requirements.

  • DISC - The Average Hop Count Measure for Virtual Path Layouts
    Lecture Notes in Computer Science, 2001
    Co-Authors: David Peleg, Uri Pincas
    Abstract:

    This paper studies the average Hop Count measure for virtual path layouts of ATM and optical networks. Routing in the ATM and optical network models is based on covering the network with simple virtual paths, under some constraints on the allowed load (i.e., the number of paths that can share an edge). The Hop Count is the number of edges along the virtual path.Two basic results are established concerning the average Hop Count parameter. The first concerns comparing the Maximum and average Hop Count measures assuming uniform all-to-all communication requirements. We develop a rather general connection between the two measures for virtual path layouts with bounded Maximum load. This connection allows us to extend known lower bounds on the Maximum Hop Count into ones on the average Hop Count for network families satisfying certain conditions, termed non-condensingly contractable (NCC) graph families. Using this characterization, we establish tight lower bounds on the average Hop Count of virtual path layouts with bounded Maximum load for paths, cycles, and trees.Our second result is an algorithm for designing a virtual path layout of minimum average Hop Count for a given tree network with general (weighted) one-to-all requirements.

  • Directed Virtual Path Layouts in ATM Networks
    1999
    Co-Authors: Jean-claude Bermond, David Peleg, Nausica Marlin, Stéphane Pérennes
    Abstract:

    Motivated by Asynchronous Transfer Mode (ATM) in telecommunication networks, we investigate the problem of designing a directed virtual topology on a directed physical topology, which consists in finding a set of directed virtual paths (VPs) satisfying some constraints in terms of load (the number of VPs sharing a physical link) and Hop Count (the number of VPs used to establish a connection). For both general and particular networks, such as paths, cycles, meshes, tori and trees, we derive tight bounds on the virtual diameter (the Maximum Hop Count for a connection) as a function of the network capacity (the Maximum load of a physical link).

Alfredo Navarra - One of the best experts on this subject based on the ideXlab platform.

  • Layouts for mobility management in wireless ATM networks
    Discrete Applied Mathematics, 2009
    Co-Authors: Michele Flammini, Alfredo Navarra
    Abstract:

    In this paper, we present a new model that combines quality of service and mobility aspects in wireless ATM networks. Namely, besides the Hop Count and load parameters of the basic ATM layouts, we introduce a new notion of distance that estimates the time needed to reconstruct the virtual channel of a wireless user when he moves through the network. Quality of service guarantee dictates that the rerouting phase must be imperceptible, that is, the Maximum distance between two virtual channels must be maintained as low as possible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that establishing the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.

  • Wireless ATM Layouts for Chain Networks
    Mobile Networks and Applications, 2005
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we consider the problem of constructing ATM layouts for wireless networks in which mobile users can move along a chain of base stations. We first show that deciding the existence of a layout with Maximum Hop Count h , load l and channel distance d is NP-complete for every fixed value of d greater or equal to 1. We then provide optimal layout constructions for the case d ≤2. Finally, optimal layout constructions are obtained also for any d within the class of the so-called canonic layouts, that so far have always been shown to be the optimal ones.

  • Wireless ATM Layouts for Chain Networks
    Mobile Networks and Applications, 2005
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we consider the problem of constructing ATM layouts for wireless networks in which mobile users can move along a chain of base stations. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and channel distance d is NP-complete for every fixed value of d greater or equal to 1. We then provide optimal layout constructions for the case d less than or equal to 2. Finally, optimal layout constructions are obtained also for any d within the class of the so-called canonic layouts, that so far have always been shown to be the optimal ones

  • Euro-Par - Dynamic layouts for wireless ATM
    Euro-Par 2003 Parallel Processing, 2003
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alessandro Gasparini, Alfredo Navarra
    Abstract:

    In this paper we present a new model able to combine quality of service (QoS) and mobility aspects in wireless ATM networks. Namely, besides the standard parameters of the basic ATM layouts, we introduce a new one, that estimates the time needed to reconstruct the virtual channel of a wireless user when it moves through the network. QoS guarantee dictates that the rerouting phase must be imperceptible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.

  • Dynamic Layouts for Wireless ATM
    2002
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we present a new model able to combine quality of service and mobility aspects in wireless ATM networks. Namely, besides the Hop Count and load parameters of the basic ATM layouts, we introduce a new notion of distance, that estimates the time needed to reconstruct the virtual channel of a wireless user when it moves through the network. Quality of service guarantee dictates that the rerouting phase must be imperceptible, that is the Maximum distance between two virtual channels must be maintained as low as possible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.

Ken-ichi Sato - One of the best experts on this subject based on the ideXlab platform.

Michele Flammini - One of the best experts on this subject based on the ideXlab platform.

  • Layouts for mobility management in wireless ATM networks
    Discrete Applied Mathematics, 2009
    Co-Authors: Michele Flammini, Alfredo Navarra
    Abstract:

    In this paper, we present a new model that combines quality of service and mobility aspects in wireless ATM networks. Namely, besides the Hop Count and load parameters of the basic ATM layouts, we introduce a new notion of distance that estimates the time needed to reconstruct the virtual channel of a wireless user when he moves through the network. Quality of service guarantee dictates that the rerouting phase must be imperceptible, that is, the Maximum distance between two virtual channels must be maintained as low as possible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that establishing the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.

  • Wireless ATM Layouts for Chain Networks
    Mobile Networks and Applications, 2005
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we consider the problem of constructing ATM layouts for wireless networks in which mobile users can move along a chain of base stations. We first show that deciding the existence of a layout with Maximum Hop Count h , load l and channel distance d is NP-complete for every fixed value of d greater or equal to 1. We then provide optimal layout constructions for the case d ≤2. Finally, optimal layout constructions are obtained also for any d within the class of the so-called canonic layouts, that so far have always been shown to be the optimal ones.

  • Wireless ATM Layouts for Chain Networks
    Mobile Networks and Applications, 2005
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we consider the problem of constructing ATM layouts for wireless networks in which mobile users can move along a chain of base stations. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and channel distance d is NP-complete for every fixed value of d greater or equal to 1. We then provide optimal layout constructions for the case d less than or equal to 2. Finally, optimal layout constructions are obtained also for any d within the class of the so-called canonic layouts, that so far have always been shown to be the optimal ones

  • Euro-Par - Dynamic layouts for wireless ATM
    Euro-Par 2003 Parallel Processing, 2003
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alessandro Gasparini, Alfredo Navarra
    Abstract:

    In this paper we present a new model able to combine quality of service (QoS) and mobility aspects in wireless ATM networks. Namely, besides the standard parameters of the basic ATM layouts, we introduce a new one, that estimates the time needed to reconstruct the virtual channel of a wireless user when it moves through the network. QoS guarantee dictates that the rerouting phase must be imperceptible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.

  • Dynamic Layouts for Wireless ATM
    2002
    Co-Authors: Michele Flammini, Giorgio Gambosi, Alfredo Navarra
    Abstract:

    In this paper we present a new model able to combine quality of service and mobility aspects in wireless ATM networks. Namely, besides the Hop Count and load parameters of the basic ATM layouts, we introduce a new notion of distance, that estimates the time needed to reconstruct the virtual channel of a wireless user when it moves through the network. Quality of service guarantee dictates that the rerouting phase must be imperceptible, that is the Maximum distance between two virtual channels must be maintained as low as possible. Therefore, a natural combinatorial problem arises in which suitable trade-offs must be determined between the different performance measures. We first show that deciding the existence of a layout with Maximum Hop Count h, load l and distance d is NP-complete, even in the very restricted case h=2, l=1 and d=1. We then provide optimal layout constructions for basic interconnection networks, such as chains and rings.