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TTL-CHORD: A CHORD-BASED APPROACH FOR SEMANTIC WEB SERVICES DISCOVERY

SCALABLE COMPUTING-PRACTICE AND EXPERIENCE 2014年第1期15卷 89-99页

作者： Gharzouli, Mohamed Messelem, Youcef Bounas, Mohamed Elhadi Univ Constantine 2 Fac New Technol Informat & Commun Dept IFA Constantine Algeria

Recently, P2P-based discovery methods for semantic Web services require special attention from collaboration and interoperability in distributed computing environment. In this paper, we present an approach for semantic Web services discovery through a structured P2P network based on Chord. This protocol is chosen because it is scalable and still achieves very good resilience and proximity performance. However, because the discovery of Web services is made semantically, the search time will be significant. For this reason, we integrate a proposed algorithm into original implementation of Chord, where we mark the sent requests by a TTL (Time To Live). After this proposition, we present some experimental results wherever we analyze and discuss the influence of the TTL on the discovery operation and on the network stability.

关键词： Web services discovery P2P Chord distributed algorithm

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Synergy routing and dynamic spectrum allocation in multi-hop cognitive radio networks

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IET NETWORKS 2014年第2期3卷 82-87页

作者： Zhu, Xiaorong Zhu, Hongbo Nanjing Univ Posts & Telecommun Wireless Commun Key Lab Jiangsu Prov Nanjing 210003 Jiangsu Peoples R China

To maximise spectrum efficiency and channel capacity, both unused (white) and underused (grey) spectral regions need to be exploited. The authors propose a distributed and localised algorithm for joint opportunistic routing and spectrum allocation for multi-hop cognitive radio networks, and design a synergy routing, a utility-based routing scheme that achieves synergistic cognitive radio benefits of overlay and underlay techniques and simultaneously maximises spectrum efficiency. The synergy routing opportunistically calculates the next hop according to the spectrum dynamics and residual energy of candidate relays and harvests the benefits from the cooperation of underlay and overlay spectrum. Simulation results indicate that our synergy prototype improves delay and throughput performance, while maintaining the autonomy and heterogeneity of individual underlay and overlay networks.

关键词： channel capacity cognitive radio telecommunication network routing wireless channels synergy routing dynamic spectrum allocation multihop cognitive radio networks channel capacity spectrum efficiency unused spectral regions underused spectral regions distributed algorithm localised algorithm opportunistic routing spectrum allocation utility-based routing scheme synergistic cognitive radio residual energy underlay spectrum overlay spectrum

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Optimal distributed Scheduling under Time-Varying Conditions: A Fast-CSMA algorithm with Applications

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第7期12卷 3278-3288页

作者： Li, Bin Eryilmaz, Atilla Ohio State Univ Dept Elect & Comp Engn Columbus OH 43210 USA

Recently, low-complexity and distributed Carrier Sense Multiple Access (CSMA)-based scheduling algorithms have attracted extensive interest due to their throughput-optimal characteristics in general network topologies. However, these algorithms are not well-suited for time-varying environments (i.e., serving real-time traffic under time-varying channel conditions in wireless networks) for two reasons: (1) the mixing time of the underlying CSMA Markov Chain grows with the size of the network, which, for large networks, generates unacceptable delay for deadline-constrained traffic;(2) since the dynamic CSMA parameters are influenced by the arrival and channel state processes, the underlying CSMA Markov Chain may not converge to a steady-state under strict deadline constraints and fading channel conditions. In this paper, we attack the problem of distributed scheduling for time-varying environments. Specifically, we propose a Fast-CSMA (FCSMA) policy in fully-connected topologies, which converges much faster than the existing CSMA algorithms and thus yields significant advantages for time-varying applications. Then, we design optimal policies based on FCSMA techniques in two challenging and important scenarios in wireless networks for scheduling inelastic traffic with/without channel state information (CSI) over wireless fading channels.

关键词： CSMA wireless fading deadline-constrained scheduling distributed algorithm

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A distributed Resource Allocation algorithm in Multiservice Heterogeneous Wireless Networks 7th

A Distributed Resource Allocation Algorithm in Multiservice ...

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7th International ICST Wireless Internet Conference (WICON)

作者： Fan, Juan Zhou, Wuyang Univ Sci & Technol China Dept Elect Engn & Informat Sci Wireless Informat Network Lab Hefei 230026 Anhui Peoples R China

ISBN: (纸本)9783642417733;9783642417726

In this paper, radio resource allocation and users to access networks assignment in heterogeneous wireless networks is studied. Mobile terminals are assumed to have the capability of using multiple radio access technologies simultaneously. A joint optimization problem is formulated, which guarantees services for terminals and maximizes the sum utility of all base stations/access points. Our model applies to arbitrary heterogeneous scenarios where the air interfaces belong to the class of interference limited systems like CDMA-based UMTS or to a class with orthogonal resource assignment such as TDMA-based GSM, WLAN or OFDMA-based LTE. Dual decomposition is employed to solve this optimization problem and a distributed iterative algorithm is developed. Simulation results demonstrate the validity of the proposed algorithm.

关键词： heterogeneous wireless networks resource allocation distributed algorithm dual decomposition

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A distributed Scheduling algorithm for Wireless Networks with Constant Overhead and Arbitrary Binary Interference

A Distributed Scheduling Algorithm for Wireless Networks wit...

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2010 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems

作者： Bermond, Jean-Claude Mazauric, Dorian Misra, Vishal Nain, Philippe Univ Nice Sophia INRIA I3S CNRS Sophia Antipolis France

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distributed Network Localization Using Angle-of-Arrival Information Part II: Discrete-Time algorithm and Error Analysis

Distributed Network Localization Using Angle-of-Arrival Info...

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American Control Conference (ACC)

作者： Zhu, Guangwei Hu, Jianghai Purdue Univ Sch Elect & Comp Engn W Lafayette IN 47907 USA

ISBN: (纸本)9781479901784

In this paper, we propose a discrete-time distributed algorithm for network localization based on angle-of-arrival (AOA) measurements. This algorithm can be viewed as a special case of the averaging consensus algorithm in the two-dimensional space. We also analyze the localization error under inaccurate anchor positions and angles measurements and provide approximate formulae for the error terms. The effectiveness of our localization algorithm and error assessment tools is demonstrated through numerical examples. The main contribution of our paper lies in the theoretical framework for analyzing AOA-based localization processes as well as assessing localization error.

关键词： localization angle-of-arrival (AOA) estimation stiffness matrix optimization distributed algorithm

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A distributed Power Allocation algorithm for OFDM-Based Cognitive Radio Networks

A Distributed Power Allocation Algorithm for OFDM-Based Cogn...

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IEEE International Conference of Region 10 (TENCON)

作者： Ma, Ning Yang, Mochan Shin, Yoan Soongsil Univ Sch Elect Engn Seoul 156743 South Korea

ISBN: (纸本)9781479928255;9781479928279

The lack of wireless spectrum resource is one of the main factors constraining the further development of wireless communication, and this has been receiving increasing research attention. Cognitive radio (CR) has been demonstrated as a good solution to improve resource efficiency. Moreover, orthogonal frequency division multiplexing (OFDM) technology has become the preferred technique in CR systems due to its flexible dynamic resource allocation. We propose a distributed resource allocation framework based on the particle swarm optimization (PSO) algorithm for CR networks utilizing an OFDM-based system. Our main aim is to maximize the system throughput subject to constraints and put forward a computationally efficient, suboptimal power allocation algorithm for multi-user OFDM CR system. Simulation results are provided to evaluate the performance of the PSO algorithm in comparison with the optimal Lagrange dual method.

关键词： Cognitive radio OFDM power allocation particle swarm optimization distributed algorithm

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Design and Implementation of a distributed WLS Localization and Tracking algorithm in Wireless Sensor Network

Design and Implementation of a Distributed WLS Localization ...

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IEEE Wireless Communications and Networking Conference (WCNC)

作者： Wang, Ching-Hsien Tsai, Pei-Yun Natl Cent Univ Dept Elect Engn Tao Yuan Taiwan

ISBN: (纸本)9781467359399;9781467359382

In this paper, a distributed algorithm for localization and tracking in wireless sensor network is designed and implemented. Combining the fingerprint approach and subgradient optimization, the proposed algorithm, called golf algorithm, uses different strategies to attain fast movement for tracking a moving object and a fine tune to approach a stationary object, like a drive and a putt on the putting green in the golf. Based on the WLS objective function, a recursive form for both the fingerprint approach and subgradient optimization is derived and can be accomplished by anchor nodes in collaboration. From simulation results, we can see the proposed algorithm has better estimation performance than the conventional decentralized algorithms to localize a stationary or moving target in large wireless sensor networks. In addition, its hardware architecture is designed. The CORDIC operation is employed to compute the vector norm. Parallel processing is used to handle the calculation of fingerprint data. The tracking trajectories of the floating-point program and fixed-point hardware implementation are shown to be quite similar with small finite precision effect, which verifies the feasibility of this hardware solution.

关键词： positioning distributed algorithm and subgradient optimization fingerprint

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NEAR-FIELD SOURCE EXTRACTION USING SPEECH PRESENCE PROBABILITIES FOR AD HOC MICROPHONE ARRAYS 14

NEAR-FIELD SOURCE EXTRACTION USING SPEECH PRESENCE PROBABILI...

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14th International Workshop on Acoustic Signal Enhancement (IWAENC)

作者： Taseska, Maja Markovich-Golan, Shmulik Habets, Emanuel A. P. Gannot, Sharon Int Audio Labs Erlangen D-91058 Erlangen Germany Bar Ilan Univ Fac Engn IL-52900 Ramat Gan Israel

ISBN: (纸本)9781479968084

Ad hoc wireless acoustic sensor networks (WASNs) hold great potential for improved performance in speech processing applications, thanks to better coverage and higher diversity of the received signals. We consider a multiple speaker scenario where each of the WASN nodes, an autonomous system comprising of sensing, processing and communicating capabilities, is positioned in the near-field of one of the speakers. Each node aims at extracting its nearest speaker while suppressing other speakers and noise. The ad hoc network is characterized by an arbitrary number of speakers/nodes with uncontrolled microphone constellation. In this paper we propose a distributed algorithm which shares information between nodes. The algorithm requires each node to transmit a single audio channel in addition to a soft time-frequency (TF) activity mask for its nearest speaker. The TF activity masks are computed as a combination of estimates of a model-based speech presence probability (SPP), direct to reverberant ratio (DRR) and direction of arrival (DOA) per TF bin. The proposed algorithm, although sub-optimal compared to the centralized solution, is superior to the single-node solution.

关键词： ad hoc networks direction-of-arrival estimation microphone arrays noise abatement probability reverberation speaker recognition time-frequency analysis wireless sensor networks DOA DRR SPP TF activity TF bin WASN nodes ad hoc microphone arrays ad hoc wireless acoustic sensor networks direct to reverberant ratio direction of arrival distributed algorithm information sharing microphone constellation model-based speech presence probability near-field source extraction nearest speaker extraction noise suppression single audio channel single-node solution soft time-frequency activity speech processing applications Acoustics Covariance matrices Direction-of-arrival estimation Microphones Noise Speech Vectors Direction of arrival estimation microphone arrays distributed algorithms Microphone Device Component Noise control Noise abatement Ad hoc networks United States Department of Agriculture STANDARD PRACTICE PROCEDURES Noise suppression speaker recognition Reverberation Time frequency analysis Speech Information Sharing

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A distributed Self-Healing algorithm for Virtual Backbone Construction and Maintenance in Wireless Sensor Networks

A Distributed Self-Healing Algorithm for Virtual Backbone Co...

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IEEE International Conference on Wireless for Space and Extreme Environments

作者： Al-Nabhan, Najla Al-Rodhaan, Mznah Al-Dhelaan, Abdullah King Saud Univ Dept Comp Sci Riyadh Saudi Arabia

ISBN: (纸本)9781479929597

Future Wireless Sensor Networks (WSNs) will be composed of a large number of densely deployed sensors. A key feature of such networks is that their nodes are untethered and unattended. distributed techniques are expected in WSNs. Computing Connected Dominating Sets (CDSs) have been widely used for virtual backbone construction in WSNs to control topology, facilitate routing, and extend network lifetime. This paper proposes a new distributed algorithm for CDS construction in WSNs. The algorithm is intended to construct a CDS with the smallest ratio when compared to its centralized version. Moreover, this paper proposes a localized algorithm that efficiently maintains the backbone when some backbone nodes decide to enter the energy saving sleep mode. We attempt to prolong the lifetime of the constructed CDS by allowing nodes with higher residual energy to have more chances to be part of the constructed and maintained backbone. Simulation shows that our distributed approach has a maximum ratio of 1.53 to the centralized approach, and it satisfies all of the geometrical properties of its canalized version. Based on this ratio, this distributed algorithm has an approximation factor of 7.65 to the optimal CDS. To the best of our knowledge, this approximation is the smallest among all existing distributed CDS construction algorithms.

关键词： wireless sensor network energy-aware algorithm distributed algorithm virtual backbone connected dominating set

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