检索结果-内蒙古大学图书馆

MILCOM, Military Communications Conference

作者： D. Liu N. Ansari E. Hou Advanced Networking Laboratory Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

In this paper, we propose a new fairness criterion-queue proportional fairness (QPF)- that employs the cell loss ratio as the fairness metric to improve the utilization of switch resources. In QPF, bandwidth allocatio... 详细信息

ISBN: (纸本)0780372255

关键词： Switches Bandwidth Traffic control Resource management Throughput Communication system traffic control Asynchronous transfer mode Fabrics Scheduling algorithm Laboratories

来源：评论

学校读者我要写书评

暂无评论

On-line dynamic bandwidth allocation for VBR video transmission

On-line dynamic bandwidth allocation for VBR video transmiss...

引用

International Conference on Information Technology: Coding and Computing (ITCC)

作者： Hai Liu N. Ansari Y.Q. Shi Advanced Networking Laboratory Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

ISBN: (纸本)0769510620

To guarantee quality of service (QoS), the requirements for video transmission, such as delay and cell loss rate (CLR), are very stringent. These constraints are difficult to meet if high network utilization is desired. In this paper, online dynamic bandwidth allocation algorithms, in which the bandwidth is adjusted based on the current frame size, are proposed to improve the bandwidth utilization. When the bandwidth deviation is large enough, a bandwidth re-negotiation process is triggered. Compared with a constant bit-rate (CBR) service, network utilization can be improved significantly for the same CLR. In general, to achieve a very low CLR and high bandwidth utilization, the re-negotiation frequency may become high. Algorithms which have been proven to be effective in reducing the re-negotiation frequency while keeping the bandwidth utilization at a reasonable level are also proposed.

关键词： Channel allocation Quality of service Bandwidth Telecommunication traffic Bit rate Uninterruptible power systems Frequency Quality management Costs Heuristic algorithms

来源：评论

学校读者我要写书评

暂无评论

An adaptive segmentation scheme for the Bluetooth-based wireless channel 10

An adaptive segmentation scheme for the Bluetooth-based wire...

引用

10th International Conference on computer Communications and Networks, ICCCN 2001

作者： Kim, Jesung Lim, Yujin Kim, Yongsuk Ma, Joong Soo School of Computer Science and Engineering Seoul National University Seoul Korea Republic of Department of Mechanical Engineering University of Seoul Seoul Korea Republic of i-Networking Lab. Samsung Advanced Institute of Technology Suwon Korea Republic of Information and Communications University Taejon Korea Republic of

ISBN: (纸本)0780371283

Bluetooth has been regarded as a promising solution for wireless connection between hand-held devices. In Bluetooth, a message is segmented into short packets to be transmitted over different frequency bands to randomize error occurrences. There are various kinds of packets with different sizes and error-handling schemes. Since each packet type has its own performance characteristics, care must be taken in selecting a packet type. This paper proposes an adaptive method that selects the best packet type depending on the condition of the channel. One of challenging issues in the proposed scheme is how to predict the packet error rate of one packet type from another. We interpolate packet error rates of different packets based on a uniform bit error model. Based on the packet error rates obtained from the interpolation, the proposed scheme selects a packet type that leads to the best performance. We also propose a revised scheme that works even when bit errors occur in a non-uniform pattern. The proposed scheme is especially useful in a harsh environment where the bit error rate is worse than 10-4. © 2001 IEEE.

关键词： Quality of service

来源：评论

学校读者我要写书评

暂无评论

Mobility-adaptive protocols for managing large ad hoc networks

Mobility-adaptive protocols for managing large ad hoc networ...

引用

IEEE International Conference on Communications (ICC)

作者： S. Basagni D. Turgut S.K. Das Center for Advanced Telecommunications Systems and Services Erik Jonsson School of Engineering and Computer Science University of Texas Dallas USA Center for Research in Wireless Mobility and Networking Department of Computer Science and Engineering University of Texas Arlington USA

We propose a new protocol for efficiently managing large ad hoc networks, i.e., networks in which all nodes can be mobile. We observe that, since nodes in such networks are not necessarily equal in that they may have different resources, not all of them should be involved in basic network operations such as packet forwarding, flooding, etc. In the proposed protocol, a small subset of the network nodes is selected based on their status and they are organized to form a backbone (whence the name "backbone protocol" or simply B-protocol to our proposed solution). The B-protocol operates in two phases: first the "most suitable" nodes are selected to serve as backbone nodes, then the selected nodes are linked to form a backbone which is guaranteed to be connected if the original network is. The effectiveness of the B-protocol in constructing and maintaining in face of node mobility and node/link failure a connected backbone that uses only a small fraction of the nodes and of the links of the original networks is demonstrated via simulation. The obtained results show that both the selected backbone nodes and the links between them in the backbone are considerably smaller than the nodes and the links in the flat network.

关键词： Ad hoc networks Spine computer network management computer science Electronic mail Routing protocols Multicast protocols Bandwidth Microstrip Wireless application protocol

来源：评论

学校读者我要写书评

暂无评论

An adaptive segmentation scheme for the Bluetooth-based wireless channel

An adaptive segmentation scheme for the Bluetooth-based wire...

引用

International Conference on computer Communications and Networks (ICCCN)

作者： Jesung Kim Yujin Lim Yongsuk Kim Joong Soo Ma School of Computer Science and Engineering Seoul National University Seoul South Korea Department of Mechanical Engineering University of Seoul Seoul South Korea I-Networking Laboratory Samsung Advanced Institute of Technology Suwon South Korea Information and Communications University Taejon South Korea

关键词： Bluetooth Error analysis Bit error rate Frequency computer errors Protocols Quality of service computer science Mechanical engineering Interpolation

来源：评论

学校读者我要写书评

暂无评论

Spectral analysis of connection utilization masking in ATM networks

Spectral analysis of connection utilization masking in ATM n...

引用

International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： A. Cay J. McEachen Advanced Networking Laboratory Department of Electrical and Computer Engineering Naval Postgraduate School Monterrey CA USA

"Cell injection" is a technique for masking virtual connection (VC) utilization in ATM networks from third parties by providing a constant or near-constant flow of traffic over the connection. This paper models the cell injection process as a Markov modulated Poisson process (MMPP) and discusses both the theoretical and applied aspects of the cell injection approach. Analytic results are compared with measurements of real cell-injected ATM traffic and the effects of injection on the original traffic are summarized. Second order statistics, autocorrelation and power spectral density, of the cell-injected and original streams are used compare and justify these effects. These measurements show that cell injection shifts the power in the mid and high frequency regions towards low frequency regions, which is the dominant factor in queue length distributions.

关键词： Spectral analysis Intelligent networks Traffic control Asynchronous transfer mode Cryptography Frequency Switches Payloads Telecommunication traffic Contracts

来源：评论

学校读者我要写书评

暂无评论

Multiplexing VBR video and training sequences on wireless fading channels

Multiplexing VBR video and training sequences on wireless fa...

引用

MILCOM, Military Communications Conference

作者： F. Freiha K. Chandra V. Mehta C. Thompson Center for Advanced Computation and Telecommunication Department of Electrical and Computer Engineering University of Massachusetts Lowell Lowell MA USA Optical Networking Group Lucent Technologies Inc. Andover MA USA

A time slotted multiple access scheme that shares bandwidth between source and training signals is proposed for the transmission of variable bit rate (VBR) video signals over non-ideal channels. The error performance is examined using finite state Markov chains that model both the VBR source traffic and the time variation of fading channels. The characteristic time-scale of the fade duration, the step-size parameter of the LMS equalizer training algorithm, and the number of training sequences allocated per time slot jointly influence the error performance. The consideration of the physical layer characteristics in the design of higher layer protocols enhances the performance of conventional application layer based preventive and reactive error control schemes. Simulation results for fast and slow fading channels show that the proposed channel access scheme can lead to an order of magnitude decrease in the bit error ratio if the combination of training overhead and step-size parameter are chosen judiciously with respect to the fading time-scale. In addition, the multiplexing efficiency of VBR encoded video is shown to be useful for limiting the channel access delays when training overhead is increased.

关键词： Fading Video sharing Bandwidth Bit rate Traffic control Least squares approximation Equalizers Physical layer Access protocols Error correction

来源：评论

学校读者我要写书评

暂无评论

Performance of VBR video with equalization on wireless fading channels

Performance of VBR video with equalization on wireless fadin...

引用

Seamless Interconnection for Universal Services. Global Telecommunications Conference. GLOBECOM'99. (Cat. No.99CH37042)

作者： F. Freiha K. Chandra V. Mehta C. Thompson Center for Advanced Computation and Telecommunications Department of Electrical and Computer Engineering University of Massachusetts Lowell Lowell MA USA Optical Networking Group Lucent Technologies Bell Laboratories North Andover MA USA

The error and delay performance of variable bit rate (VBR) video transmission over non-ideal channels is examined using equalization schemes. The temporal correlation features of the fading signal and the source video are modeled using finite state Markov chains. The source and training signals are multiplexed using a time slotted multiple access scheme. For slow-fading channels, the characteristic time-scale of the fade durations, the step-size parameter of the LMS equalizer training algorithm, and the number of training sequences allocated per time slot are found to jointly influence error performance. Simulation results show that the proposed channel access scheme can lead to an order of magnitude decrease in the bit error ratio if the combination of training overhead and step-size parameter are chosen judiciously with respect to the fading time-scale. In addition, the multiplexing efficiency of VBR encoded video is shown to be useful for limiting the channel access delays when the training overhead is increased.

关键词： Fading Error correction Bit rate Delay Time division multiple access Bandwidth Forward error correction Equalizers Layout Video sharing

来源：评论

学校读者我要写书评

暂无评论

Tradeoffs in implementing primary-backup protocols

Tradeoffs in implementing primary-backup protocols

引用

International Symposium on Parallel and Distributed Processing (IPDPS)

作者： N. Budhiraja K. Marzullo IBM Thomas J. Watson Research Center Advanced Networking Laboratory Hawthorne NY USA Department of Computer Science and Engineering University of California San Diego La Jolla CA USA

One way to implement a fault-tolerant service is to replicate the state of the service across a primary server and a set of backup servers. Clients make requests to the primary, which then computes the response, informs the backups of the state change, and then replies to the client. If the primary subsequently fails, then a backup takes over as the new primary. Informally, a primary-backup protocol is non-blocking if the primary need not wait for acknowledgements from the backup before responding to the client; otherwise, the protocol is blocking. While most of the existing protocols are blocking, we show that non-blocking protocols can be constructed for the kinds of failures that are expected to occur in many future primary-backup systems. We implement and measure the performance in failure-free runs of two kinds of non-blocking protocols-one based on point-to-point communication and one based on broadcast-and compare the results with conventional blocking primary-backup protocols. Finally, we discuss extending our results to runs with failures.

关键词： Protocols Delay Network servers Fault tolerance Broadcasting Intelligent networks NASA computer science Uninterruptible power systems Hardware

来源：评论

学校读者我要写书评

暂无评论

PERFORMANCE OF A PRIORITIZED ON-BOARD BASEBAND SWITCH FOR A MULTISERVICE MULTIBEAM SATELLITE

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 283-297页

作者： BOHM, S ELHAKEEM, AK HACHICHA, M Department of Electrical and Computer Engineering Concordia University 1455 De Maisonneuve Blvd. West Montreal H3A 1M8 Canada Was born in Montreal Canada on 14 September 1966. He received the B. Eng. degree in electrical engineering from Concordia University Montreal Canada in 1989. He is at present completing the M.A.Sc. degree in electrical engineering at Concordia University. (S'75–S'79–M'79–SM'86) received the Ph.D. degree from Southern Methodist University Dallas TX in 1979. He spent the next two years working as a Visiting Professor in Egypt after which he moved to Ottawa Canada in 1982. He assumed teaching and research positions in Carleton and Manitoba Univerities and later moved to Concordia University Montreal Canada in 1983 where he is now a Professor in the Electrical and Computer Engineering Department. He has published numerous papers in IEEE and international journals in the areas of spread spectrum and networking. He is a well-known expert in these areas and serves as a consultant to many companies. His current research interests include wide-band metropolitan networks switching architectures and performance of on-board multibeam satellites acquisitionless CDMA networks code distribution and orthogonalization of CDMA signals responsive congestion control for ATM-based networks ARQ techniques and investigation of the novel SUGAR CDMA systems in fading channels. Dr. Elhakeem is a Senior Member of the Canadian Electrical Engineering Society and Armed Forces Association. He has chaired numerous technical sessions in IEEE Conferences was the Technical Program Chairman for IEEE Montech 1986 Montreal Canada. Dr. Elhakeem is the key guest editor of theIEEE Journal of Selected Areas in Communicationsfor the May June issues 1993 covering CDMA networks. Advanced Technology & Networks VISTAR Telecommunications Inc. Ottawa Ontario K1G 3J4 Canada An Associate Director of Advanced Technology & Networks Group VISTAR Telecommunications Inc. Ottawa Canada. He is also an Adjunct Pr

In this paper, we study the performance of a prioritized on-board baseband switch in conjunction with a multibeam satellite handling integrated services. The services considered for the analysis include voice, video, file transfer and interactive data. The prioritized switch uses both input and output buffering, switch speed-up as well as a two-phase head-of-line resolution algorithm, in order to reduce the buffer loss while maintaining acceptable user delays. The minimum required buffer capacity and switch speed-up for each service in a prioritized environment are found under uniform traffic conditions. It is shown that under uniform traffic conditions, only minimal buffering and switch speed-up are needed even for the lowest priority users. The performance dependence on the switch size is also substantially reduced with head of line resolution and buffering even in a prioritized environment.

关键词： SWITCH ON-BOARD BASEBAND MULTIBEAM PRIORITIZED HEAD-OF-LINE UNIFORM LOAD SPEED-UP

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：