The Experts below are selected from a list of 35277 Experts worldwide ranked by ideXlab platform
Andrew Brzezinski - One of the best experts on this subject based on the ideXlab platform.
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GLOBECOM - Physical Topology design for survivable routing of logical rings in WDM-based networks
IEEE Journal on Selected Areas in Communications, 2004Co-Authors: Aradhana Narula-tam, Eytan Modiano, Andrew BrzezinskiAbstract:In a wavelength-division multiplexed (WDM)-based network, a single Physical link failure may correspond to multiple logical link failures. As a result, two-connected logical topologies, such as rings routed on a WDM Physical Topology, may become disconnected after a single Physical link failure. We consider the design of Physical topologies that ensure logical rings can be embedded in a survivable manner. This is of particular interest in metropolitan area networks, where logical rings are in practice almost exclusively employed for providing protection against link failures. First, we develop necessary conditions for the Physical Topology to be able to embed all logical rings in a survivable manner. We then use these conditions to provide tight bounds on the number of Physical links that an N-node Physical Topology must have in order to support all logical rings for different sizes K. We show that when K/spl ges/4 the Physical Topology must have at least 4N/3 links, and that when K/spl ges/6 the Physical Topology must have at least 3N/2 links. Subsequently, we generalize this bound for all K/spl ges/4. When K/spl ges/N-2, we show that the Physical Topology must have at least 2N-4 links. Finally, we design Physical topologies that meet the above bounds for both K=4 and K=N-2. Specifically, our Physical Topology for embedding (N-2)-node rings has a dual hub structure and is able to embed all rings of size less than N-1 in a survivable manner. We also provide a simple extension to this Topology that addresses rings of size K=N-1 and rings of size K=N for N odd. We observe that designing the Physical Topology for supporting all logical rings in a survivable manner does not use significantly more Physical links than a design that only supports a small number of logical rings. Hence, our approach of designing Physical topologies that can be used to embed all possible ring logical topologies does not lead to a significant overdesign of the Physical Topology.
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Physical Topology design for survivable routing of logical rings in wdm based networks
Global Communications Conference, 2003Co-Authors: Aradhana Narulatam, Eytan Modiano, Andrew BrzezinskiAbstract:In a wavelength-division multiplexed (WDM)-based network, a single Physical link failure may correspond to multiple logical link failures. As a result, two-connected logical topologies, such as rings routed on a WDM Physical Topology, may become disconnected after a single Physical link failure. We consider the design of Physical topologies that ensure logical rings can be embedded in a survivable manner. This is of particular interest in metropolitan area networks, where logical rings are in practice almost exclusively employed for providing protection against link failures. First, we develop necessary conditions for the Physical Topology to be able to embed all logical rings in a survivable manner. We then use these conditions to provide tight bounds on the number of Physical links that an N-node Physical Topology must have in order to support all logical rings for different sizes K. We show that when K/spl ges/4 the Physical Topology must have at least 4N/3 links, and that when K/spl ges/6 the Physical Topology must have at least 3N/2 links. Subsequently, we generalize this bound for all K/spl ges/4. When K/spl ges/N-2, we show that the Physical Topology must have at least 2N-4 links. Finally, we design Physical topologies that meet the above bounds for both K=4 and K=N-2. Specifically, our Physical Topology for embedding (N-2)-node rings has a dual hub structure and is able to embed all rings of size less than N-1 in a survivable manner. We also provide a simple extension to this Topology that addresses rings of size K=N-1 and rings of size K=N for N odd. We observe that designing the Physical Topology for supporting all logical rings in a survivable manner does not use significantly more Physical links than a design that only supports a small number of logical rings. Hence, our approach of designing Physical topologies that can be used to embed all possible ring logical topologies does not lead to a significant overdesign of the Physical Topology.
Jiandong Li - One of the best experts on this subject based on the ideXlab platform.
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An algorithm for discovering Physical Topology in single subnet IP networks
19th International Conference on Advanced Information Networking and Applications (AINA'05) Volume 1 (AINA papers), 2005Co-Authors: Yuzhao Li, Jiandong LiAbstract:In this paper, we present a novel algorithm for discovering Physical Topology in heterogeneous (i.e. multi-vendor) single subnet IP networks. Our algorithm is based on standard SNMP MIB information that is widely supported by modern IP network elements. Algorithm resorts to the port's traffic when AFT information is insufficient. Simulation and analysis results show that this algorithm can discover the Physical network Topology accurately even if SNMP is not supported by some network elements.
Zhang Chan - One of the best experts on this subject based on the ideXlab platform.
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Physical Topology Discovery Algorithm Based on Spanning Tree Protocol
Computer Engineering, 2008Co-Authors: Zhang ChanAbstract:Topology discovery is an important foundation for network management. This paper proposes a new Physical Topology discovery algorithm relying on Spanning Tree Protocol(STP). The algorithm gets spanning tree status information of each switch by SNMP. According to STP, Physical Topology of the network is derived. Comparing with other existing algorithms, the algorithm does not require that the FDB information of each bridge is complete. Meanwhile, it can find backup link and equipments that do not support SNMP such as hub and dump switches. Experiments show that the algorithm is an accurate, comprehensive Topology discovery algorithm.
Xianbin Wang - One of the best experts on this subject based on the ideXlab platform.
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Cloud-Orchestrated Physical Topology Discovery of Large-Scale IoT Systems Using UAVs
IEEE Transactions on Industrial Informatics, 2018Co-Authors: Xianbin Wang, Jiong Jin, Kenneth McisaacAbstract:Wireless sensor networks (WSNs) have been rapidly integrated into Internet of Things (IoT) systems, empowering rich and diverse applications such as large-scale environment monitoring. However, due to the random deployment of sensor nodes (SNs), Physical Topology of the WSNs cannot be controlled and typically remains unknown to the IoT cloud server. Therefore, in order to derive the Physical Topology at the cloud for effective real-time event detection, a cloud-orchestrated Physical Topology discovery scheme for large-scale IoT systems using unmanned aerial vehicles (UAVs) is proposed in this paper. More specifically, the large-scale monitoring area is first split into a number of subregions for UAV-enabled data collection. Within the subregions, parallel Metropolis–Hastings random walk (MHRW) is developed to gather the information of WSN nodes, including their IDs and neighbor tables. The collected information is then forwarded to the cloud through UAVs for the initial generation of logical Topology. Thereafter, a network-wide 3-D localization algorithm is further developed based on the discovered logical Topology and multidimensional scaling method (Topo-MDS), where the UAVs equipped with global positioning system are served as mobile anchors to locate the SNs. Simulation results indicate that the parallel MHRW improves both the efficiency and accuracy of logical Topology discovery. In addition, the Topo-MDS algorithm dramatically improves the 3-D location accuracy, as compared to the existing algorithms in the literature.
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Physical Topology discovery scheme for wireless sensor networks using random walk process
Global Communications Conference, 2016Co-Authors: Tianqi Yu, Xianbin Wang, Abdallah ShamiAbstract:Wireless sensor networks (WSNs) are widely considered as the most important information gathering platform in enabling Internet of Things (IoT). In order to evolve the traditional WSNs for low-power and low-loss IoT applications, time slotted channel hopping (TSCH) MAC protocol has been proposed to tackle the single channel and inefficient medium access drawbacks through improved network Topology awareness. However, the problem of maintaining the Physical Topology of a WSN at the server end remains unresolved. In this paper, we propose a novel Physical Topology discovery scheme for WSNs by exploitation of random walk process and iterative multilateration localization algorithm. Explicitly, information specific to the sensor nodes, including IDs and neighbor tables, are collected in the random walk process. The Physical Topology is then reconstructed at the server end based on the collected information and the iterative multilateration localization algorithm. Simulation results indicate that the average location offset between the established Topology and the ground- truth Topology can be as low as 1.26m.
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GLOBECOM - Physical Topology Discovery Scheme for Wireless Sensor Networks Using Random Walk Process
2016 IEEE Global Communications Conference (GLOBECOM), 2016Co-Authors: Tianqi Yu, Xianbin Wang, Abdallah ShamiAbstract:Wireless sensor networks (WSNs) are widely considered as the most important information gathering platform in enabling Internet of Things (IoT). In order to evolve the traditional WSNs for low-power and low-loss IoT applications, time slotted channel hopping (TSCH) MAC protocol has been proposed to tackle the single channel and inefficient medium access drawbacks through improved network Topology awareness. However, the problem of maintaining the Physical Topology of a WSN at the server end remains unresolved. In this paper, we propose a novel Physical Topology discovery scheme for WSNs by exploitation of random walk process and iterative multilateration localization algorithm. Explicitly, information specific to the sensor nodes, including IDs and neighbor tables, are collected in the random walk process. The Physical Topology is then reconstructed at the server end based on the collected information and the iterative multilateration localization algorithm. Simulation results indicate that the average location offset between the established Topology and the ground- truth Topology can be as low as 1.26m.
Abdallah Shami - One of the best experts on this subject based on the ideXlab platform.
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Physical Topology discovery scheme for wireless sensor networks using random walk process
Global Communications Conference, 2016Co-Authors: Tianqi Yu, Xianbin Wang, Abdallah ShamiAbstract:Wireless sensor networks (WSNs) are widely considered as the most important information gathering platform in enabling Internet of Things (IoT). In order to evolve the traditional WSNs for low-power and low-loss IoT applications, time slotted channel hopping (TSCH) MAC protocol has been proposed to tackle the single channel and inefficient medium access drawbacks through improved network Topology awareness. However, the problem of maintaining the Physical Topology of a WSN at the server end remains unresolved. In this paper, we propose a novel Physical Topology discovery scheme for WSNs by exploitation of random walk process and iterative multilateration localization algorithm. Explicitly, information specific to the sensor nodes, including IDs and neighbor tables, are collected in the random walk process. The Physical Topology is then reconstructed at the server end based on the collected information and the iterative multilateration localization algorithm. Simulation results indicate that the average location offset between the established Topology and the ground- truth Topology can be as low as 1.26m.
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GLOBECOM - Physical Topology Discovery Scheme for Wireless Sensor Networks Using Random Walk Process
2016 IEEE Global Communications Conference (GLOBECOM), 2016Co-Authors: Tianqi Yu, Xianbin Wang, Abdallah ShamiAbstract:Wireless sensor networks (WSNs) are widely considered as the most important information gathering platform in enabling Internet of Things (IoT). In order to evolve the traditional WSNs for low-power and low-loss IoT applications, time slotted channel hopping (TSCH) MAC protocol has been proposed to tackle the single channel and inefficient medium access drawbacks through improved network Topology awareness. However, the problem of maintaining the Physical Topology of a WSN at the server end remains unresolved. In this paper, we propose a novel Physical Topology discovery scheme for WSNs by exploitation of random walk process and iterative multilateration localization algorithm. Explicitly, information specific to the sensor nodes, including IDs and neighbor tables, are collected in the random walk process. The Physical Topology is then reconstructed at the server end based on the collected information and the iterative multilateration localization algorithm. Simulation results indicate that the average location offset between the established Topology and the ground- truth Topology can be as low as 1.26m.