检索结果-内蒙古大学图书馆

Combating the bloated state problem in mobile agents based network monitoring applications

COMPUTER NETWORKS 2008年第17期52卷 3218-3228页

作者： Verma, Vijay K. Joshi, Ramesh C. Xie, Bin Agrawal, Dharma P. Univ Cincinnati Dept Comp Sci OBR Ctr Distributed & Mobile Computing Cincinnati OH 45221 USA Indian Inst Technol Dept Elect & Comp Sci Roorkee Uttar Pradesh India

As computer networks increase in size, it is critical to provide efficient and scalable network management. Integration of mobile agents (MAs) with simple network management protocol (SNMP) provides a decentralized network management architecture that overcomes the limitations of the legacy SNMP client/server structure. However, as an MA travels through its itinerary, acquiring the network state at each managed node, its size linearly increases node-by-node and it may be unexpectedly bloated. As a result, a bloated MA will have difficulty in migrating from one node to another. We show that the network response time grows exponentially as the MA size increases linearly. In this paper, we propose a new strategy called itinerary partitioning approach (IPA) that exploits cloning capability of MAs to effectively address this bloated state phenomenon. The analytical model shows the effectiveness of our proposed IPA in terms of network response time. We have implemented the IPA in a practical test-bed network and the results seem to be very encouraging. (C) 2008 Elsevier B.V. All rights reserved.

关键词： Bloated state Cloning Itinerary partitioning mobile agent Network management Simple network management protocol (SNMP)

来源：评论

学校读者我要写书评

暂无评论

Secure and efficient authentication in Wireless Mesh Networks using merkle trees

Secure and efficient authentication in Wireless Mesh Network...

引用

Conference on Local Computer Networks (LCN)

作者： Lakshmi Santhanam Bin Xie Dharma P. Agrawal OBR Center for Distributed and Mobile Computing Department of ECECS University of Cincinnati Cincinnati OH USA

In the recent years, wireless mesh network (WMN) has evolved as a new paradigm for broadband wireless Internet access. The self-configurability, open wireless infrastructure, and different management styles of WMN make them vulnerable to malicious attackers. As a first step to secure WMNs, it is critical to incorporate an authentication mechanism for mesh clients. The existing proposals are primarily based on public key certificates, which incur considerable overhead in signature verification. We propose a network layer authentication mechanism called Merkle Tree based Mesh Authentication Protocol (MT-MAP) for WMNs. It incorporates inexpensive hash operations using Merkle tree to authenticate single/multihop mesh clients. We also show how the use of hash tree facilitates fast and periodic refresh of authentication certificates. Finally, we present a security analysis of MT-MAP against impersonation and replay attacks.

关键词： Authentication Security Servers Protocols IEEE 802.11 Standards Public key mobile communication

来源：评论

学校读者我要写书评

暂无评论

Mobility of a Base Station for Simultaneous Multiple Events in a Static Wireless Sensor Network

Mobility of a Base Station for Simultaneous Multiple Events ...

引用

IEEE National Conference on Aerospace and Electronics (NAECON)

作者： Smita Toshniwal Amit Gaur Demin Wang Dharma P. Agrawal OBR Research Center for Distributed and Mobile Computing CS Department University of Cincinnati Cincinnati OH USA

Energy constrained nature and unattended deployment of sensors motivates the need of special techniques for designing reliable wireless sensor networks. Recently many approaches are considering mobile sensor nodes to deal with this problem. But making all the sensors mobile involves more signaling overhead for network maintenance. It is energy efficient to move the base station which has no power limitations. Also, there are many real life applications in which event based approach is more appropriate. In this paper, we propose an adaptive scheme for a mobile base station that moves according to the occurrence of events. We propose two optimization schemes: moving the BS towards the event centroid and moving the BS towards distance based weighted centroid. Simulation results show that moving the base station adaptively significantly prolongs the network lifetime.

关键词： Base stations Wireless sensor networks Monitoring Surveillance Relays Medical services Network topology mobile agents mobile computing Computer networks

来源：评论

学校读者我要写书评

暂无评论

Effective Radio Partitioning and Efficient Queue Management Schemes in a Wireless Mesh Network

Effective Radio Partitioning and Efficient Queue Management ...

引用

IEEE GLOBECOM 2008 - 2008 IEEE Global Telecommunications Conference

作者： Weihuang Fu Dharma P. Agrawal OBR Center of Distributed and Mobile Computing Department of Computer Science University of Cincinnati Cincinnati OH USA

Interconnected Mesh Routers (MRs) constitute the backbone network of a Wireless Mesh Network (WMN) that provides access service to the Mesh Clients (MCs) spread over a wider region. In such an environment, multi-radio and multichannel are utilized to improve the network performance. This paper introduces an effective radio partitioning scheme and a queue management strategy that provide a novel hybrid operating mode. Few radios are dynamically switched among the channels in forwarding the packets while the rests remain at the assigned channels. The radios are allowed to adaptively change so as to meet the traffic load at a MR. Queue management changes the sequence of forwarding packet by grouping the packets over the same channel so that the channel switching overhead and the packet delay are minimized. Extensive simulations are performed to illustrate the effectiveness of our proposed scheme.

关键词： Radio spectrum management Wireless mesh networks Traffic control Packet switching Communication system traffic control Delay effects Spine Telecommunication traffic Spread spectrum communication Routing

来源：评论

学校读者我要写书评

暂无评论

Internet Gateway Deployment Optimization in a Multi-Channel Multi-Radio Wireless Mesh Network

Internet Gateway Deployment Optimization in a Multi-Channel ...

引用

IEEE Conference on Wireless Communications and Networking

作者： Bing He Bin Xie Dharma P. Agrawal OBR Center of Distributed and Mobile Computing Department of Computer Science University of Cincinnati Cincinnati OH USA

In a wireless mesh network (WMN), mesh routers (MRs) are interconnected by wireless links and form a wireless backbone to provide ubiquitous high-speed Internet connectivity for mobile clients (MCs). The wireless backbone is tightly integrated with the Internet by a special kind of nodes called as Internet gateways (IGWs). Even though the capacity of WMN can be improved by equipping the MRs with multiple radios working at non-overlapping channels, the deployment of IGW is critical to the network performance of WMN. In this paper, we address the IGW placement problem based on a hierarchical cluster based architecture. The problem is first formulated as a linear program (LP) issue, then some heuristic algorithms are developed. Our simulation results show the effectiveness of the proposed algorithms.

关键词： IP networks Wireless mesh networks Clustering algorithms Throughput Spine Heuristic algorithms Spread spectrum communication Web and internet services Quality of service mobile computing

来源：评论

学校读者我要写书评

暂无评论

Flow-Based Channel Assignment in Channel Constrained Wireless Mesh Networks

Flow-Based Channel Assignment in Channel Constrained Wireles...

引用

International Conference on Computer Communications and Networks (ICCCN)

作者： Weihuang Fu Bin Xie Xiaoyuan Wang Dharma P. Agrawal Department of Computer Science OBR Center of Distributed and Mobile Computing University of Cincinnati Cincinnati OH USA

ISBN: (纸本)9781424423897

Wireless mesh network (WMN) technology extends the service coverage by supporting multi-hop communication and enhances the network capacity by utilizing multi-radio and multichannel. The number of multiple channels is essential for the implementation and the efficiency of channel assignment. While the number of channels is not sufficient, channel assignment needs to consider the channel sharing at certain mesh routers (MRs). The distribution of traffic flows in the network greatly affects the channel assignment. Different to a mobile ad hoc network (MANET), the traffic in a WMN is predominated by the Internet traffic. In this paper, we analyze the number of channels for a feasible conflict free channel assignment in such a network. We also propose a flow-based channel assignment in the channel constrained situation by implementing channel mergence algorithm so that MRs can appropriately share the channel resource. Extensive simulations are performed to illustrate the effectiveness of our proposed scheme.

关键词： Wireless mesh networks Telecommunication traffic Traffic control mobile ad hoc networks IP networks Spread spectrum communication Linear programming Channel capacity mobile computing Computer networks

来源：评论

学校读者我要写书评

暂无评论

mobile Sensor Relocation to Prolong the Lifetime of Wireless Sensor Networks

Mobile Sensor Relocation to Prolong the Lifetime of Wireless...

引用

IEEE Conference on Vehicular Technology (VTC)

作者： Younghwan Yoo Dharma Agrawal School of Computer Science and Engineering Pusan National University Busan South Korea OBR Center for Distributed and Mobile Computing Department of CS University of Cincinnati Cincinnati OH USA

The wireless sensor network (WSN) has recently attracted considerable attention due to the low price and ease to deploy it. In particular, in a hostile or harsh regions where sensors cannot be deployed manually, WSNs can be established just by dropping sensors from the air. In this case, however, most likely sensors are not placed at optimal positions, although the location of sensors does have a drastic impact on the WSN performance. Moreover, randomized deployment algorithm can leave holes in terms of coverage in the sensing area. This paper proposes a sensor relocation scheme where mobile sensors move to patch up the holes by appropriate coverage. Simulation results show that the proposed algorithm outperforms prior existing schemes in terms of coverage and lifespan of WSNs.

关键词： Wireless sensor networks Mechanical sensors Costs mobile computing Sensor phenomena and characterization Computer science Computer networks distributed computing Temperature sensors Humidity

来源：评论

学校读者我要写书评

暂无评论

Delay and Capacity Optimization in Multi-radio Multi-channel Wireless Mesh Networks

Delay and Capacity Optimization in Multi-radio Multi-channel...

引用

IEEE International Conference on Performance, computing and Communications (IPCCC)

作者： Weihuang Fu Yun Wang Dharma P. Agrawal OBR Center for Distributed and Mobile Computing Department of Computer Science University of Cincinnati Cincinnati OH USA Department of Computer Science Southern Illinois University Edwardsville IL USA

The technology of wireless mesh network (WMN) provides a flexible Internet access service in a wide region by employing multi-hop wireless routing and enhances the network performance by utilizing multi-radio and multi-channel. Delay analysis is a fundamental issue for delay-sensitive application such as VoIP and video conference, and delay constrained capacity is essential for a network to provide satisfied service. This paper models such a network and obtains the packet delay and network capacity by considering a queueing network formed by multi-radio mesh routers (MRs) and carrier sense multiple access (CSMA) mechanism is assumed for packet transmissions over links between MRs. We investigate the problems of intercluster dominated traffic, study the impact of the number of radios and channels to the delay and the capacity, and optimize the network performance by adjusting the MR deployment and the transmission power.

关键词： Wireless mesh networks Delay Telecommunication traffic Traffic control Peer to peer computing IP networks Internet Interference Wireless networks Computer science

来源：评论

学校读者我要写书评

暂无评论

Achieving fault tolerance in data aggregation in wireless sensor networks

Achieving fault tolerance in data aggregation in wireless se...

引用

50th Annual IEEE Global Telecommunications Conference, GLOBECOM 2007

作者： Banerjee, Torsha Bin, Xie Agrawal, Dharma P. OBR Center for Distributed and Mobile Computing Dept. of Computer Science University of Cincinnati Cincinnati OH 45221-0030

ISBN: (纸本)1424410436

This paper identifies faulty sensor(s) in a polynomial-based data aggregation scenario, TREG proposed in our earlier work. In TREG, function approximation is performed over the entire range of data and only coefficients of a polynomial (P) are passed instead of aggregated data. Performing further mathematical operations on the calculated P can identify the maximum (max) and minimum (min) values of the sensed attribute and their locations. Therefore, if any sensor reports a data value outside the [min, max] range, it can be identified as a faulty sensor. We achieve the following goals: (1) uncorrelated readings from a specific sensor helps in detecting a faulty sensor, (2) faulty sensors are detected near the source and isolated preventing them from affecting the accuracy of the overall aggregated data and reducing the overall delay. Results show that a faulty sensor can be detected with an average accuracy of 94%. With increase in node density, accuracy in faulty sensor detection improves as more nodes are able to report the information to their nearest tree node. © 2007 IEEE.

关键词： Fault tolerant computer systems

来源：评论

学校读者我要写书评

暂无评论

Design of a medium access control protocol for dynamic spectrum access networks

Design of a medium access control protocol for dynamic spect...

引用

IEEE International Conference on Communications (ICC 2007)

作者： Mishra, Amitabh Agrawal, Dharma P. Virginia Polytech Inst & State Univ Bradley Dept Elect & Comp Engn Blacksburg VA 24061 USA Univ Cincinnati OBR Ctr Distributed & Mobile Computing Dept ECECS Cincinnati OH 45220 USA

ISBN: (纸本)9781424403523

In this paper we present a design of a medium access control protocol that allows the utilization of unused licensed spectrum of deployed wireless cellular systems (Primary System) by an overlaid multi-hop ad hoe network (Secondary System). The basic design principle is that the secondary operates in a non-intrusive manner and does not interact with the primary. We address a number of architectural challenges pertinent to this networking environment, and evaluate the performance of the MAC. Our performance evaluation results show that, in a single-hop ad hoc network, the proposed MAC transparently utilizes 75% of the bandwidth left unused by the primary, while, in the multi-hop cases, due to spatial reuse, the bandwidth utilization can be significantly higher.

关键词： Wireless networks

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：