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Communications Magazine, IEEE

Issue 4 • Date April 2001

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Displaying Results 1 - 16 of 16
  • High-performance communication networks, second edition [Book Review]

    Page(s): 18
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    Freely Available from IEEE
  • How network asymmetry affects TCP

    Page(s): 60 - 67
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (99 KB) |  | HTML iconHTML  

    Several emerging wireline and wireless access network technologies exhibit asymmetry in their network characteristics. For instance, cable modem networks exhibit significant bandwidth asymmetry, while packet radio networks exhibit media access asymmetry. A high degree of asymmetry can have an adverse effect on the performance of feedback-based transport protocols. We study the effects of bandwidth and media access asymmetry on the performance of the TCP protocol. We identify the fundamental reasons for the mismatch between TCP and asymmetric networks, and then present several techniques to address this problem. View full abstract»

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  • A framework for standardization in telecommunications and information technology

    Page(s): 94 - 100
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    Standards are technical products that demand a sophisticated level of strategic planning, extensive technical preparation, and superb interpersonal skills, particularly at the international level. Three tools are presented to understand how these factors interact with each other in the case of telecommunications and information technology standards. These tools can improve decisions regarding the timing of standardization, the level of detail a standard should include, and the measures of quality of the final product View full abstract»

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  • The making of standards: looking inside the work groups

    Page(s): 102 - 107
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    This article attempts to contribute to a better understanding of how standards actually emerge by taking a closer look at what is going on inside standards setting committees. It discusses the results of a study of senior committee members from the ISO, ITU and the IETF; who they are, where they come from, which rules they assume during the process, how they perceive this process, and what they feel actually influences its final outcome: the standard View full abstract»

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  • TCP performance

    Page(s): 51
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    First Page of the Article
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  • A report on recent developments in TCP congestion control

    Page(s): 84 - 90
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    This article discusses several changes to TCP's congestion control, either proposed or in progress. The changes to TCP include a limited transmit mechanism for transmitting new packets upon receipt of one or two duplicate acknowledgments, and a SACK-based mechanism for detecting and responding to unnecessary fast retransmits or retransmit timeouts. These changes to TCP are designed to avoid unnecessary retransmit timeouts, to correct unnecessary fast retransmits or retransmit timeouts resulting from reordered or delayed packets, and to assist the development of viable mechanisms for corruption notification. The changes in the network include explicit congestion notification, which builds on the addition of active queue management View full abstract»

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  • Multimedia data broadcasting strategies

    Page(s): 138 - 145
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    Data broadcasting in support of multimedia applications requires efficient use of bandwidth resources in order to maximize the availability of playout content. A broadcast architecture has been specified by the Digital Video Broadcasting consortium to allow service providers to multiplex data, using various protocols, into an MPEG-2 transport stream. This architecture, however, has not specified how to optimize the use of the broadcast channel. This article discusses certain strategies, based on test and measurement, that have been implemented to maximize the use of the broadcast channel (satellite and cable) for supporting multimedia applications View full abstract»

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  • IPR paralysis in standardization: is regulatory symmetry desirable?

    Page(s): 108 - 114
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    Fear of legal claims on intellectual property rights (IPRs) sometimes paralyzes standards processes. IPR procedures of standards bodies address such problems. However, by default unresolved problems are addressed by the legal regime. The process of JavaTM standardization, which is a red thread in this article, well illustrates what may happen. In case of conflict between IPRs and compatibility interests, the legal regime is such that mostly IPR interests preside. Should we strive for more symmetry between IPRs and compatibility interests? The usual rationale for IPR regulation is that it stimulates innovation. The author argues that the public is equally served by compatibility. She analyses to what degree the public interest in compatibility is institutionalized in European, United States, and international regulation and end with questions that are meant to fuel policy debate View full abstract»

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  • TCP performance issues over wireless links

    Page(s): 52 - 58
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    This article discusses the problems arising when the TCP/IP protocol suite is used to provide Internet connectivity over existing and emerging wireless links. Due to the strong drive toward wireless Internet access through mobile terminals, these problems must be carefully studied in order to build improved systems. We review wireless link characteristics using wireless LANs and cellular communications systems as examples. We then outline the performance problems of the TCP/IP protocol suite when employed over those links, such as degraded TCP performance due to mistaking wireless errors for congestion. We present various proposals for solving these problems and examine their benefits and limitations. Finally, we consider the future evolution of wireless systems and the challenges that emerging systems will impose on the Internet protocol suite View full abstract»

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  • Evaluating the impact of emerging streaming media applications on TCP/IP performance

    Page(s): 76 - 82
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    Emerging streaming media applications in the Internet primarily use UDP transport. The difficulty with supporting this type of traffic on the Internet is that they not only generate large volumes of traffic, but they are also not as responsive to network congestion as TCP-based applications. As a result, streaming media UDP traffic can cause two major problems in the Internet: congestion collapse and unfair allocations of bandwidth among competing traffic flows. A solution to these problems is available in many Internet environments. The Internet backbone, various ISPs, and DSL access networks rely on ATM as their layer 2 transport technology, and in such environments, ATM's available bit rate service can efficiently address these problems. ABR is able to avoid congestion collapse and provide fair bandwidth allocations by distributing the unutilized bandwidth fairly among competing flows. This article presents simulation results and empirical measurements that illustrate the congestion collapse and unfairness problems, and ATM ABR's effectiveness in addressing those problems View full abstract»

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  • Continuous-time filters in telecommunications chips

    Page(s): 132 - 137
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    Analog fully integrated continuous-time filters are reviewed. The important rule of such filters in modern telecommunications is outlined, and several techniques for their implementation in mixed-signal chips are described. The article concludes with a review of techniques at the research stage, which promise to expand the frequency range and reduce power dissipation View full abstract»

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  • Broadband communication on the highways of tomorrow

    Page(s): 146 - 154
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    Consumer demands for broadband communications at highway speeds will not likely be met by next-generation proposals. Although solutions exist for incremental improvements in capacity and bandwidth, the wireless industry has not yet offered an economical method for providing the broadband channels demanded by mobile consumers on the highway. The article examines a proposed high-capacity infrastructure with moving base stations for providing broadband communication services that are not limited by a user's speed. Moving base stations provide moving communication cells to mobile users traveling along a roadway. This broadband solution provides communication services with data rates of 20 Mb/s or more at any vehicular speed at costs comparable to wireline. In addition to presenting a general technical description of the proposed infrastructure, the discussion includes an overview of wireless technology and obstacles encountered in designing a high-capacity system providing high-bandwidth channels to users traveling at highway speeds View full abstract»

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  • End system optimizations for high-speed TCP

    Page(s): 68 - 74
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    The delivered TCP performance on high-speed networks is often limited by the sending and receiving hosts, rather than by the network hardware or the TCP protocol implementation itself. In this case, systems can achieve higher bandwidth by reducing host overheads through a variety of optimizations above and below the TCP protocol stack, given support from the network interface. This article surveys the most important of these optimizations and illustrates their effects quantitatively with empirical results from an experimental network delivering up to 2 Gb/s of end-to-end TCP bandwidth View full abstract»

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  • Telecommunications standardization for the new millennium: ITU-T's strategies

    Page(s): 124 - 130
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    After reviewing the environmental changes in telecommunications and the market trend toward global convergence, this article examines the evolution of the standards-making process, especially from an ITU's perspective. Projects on IP-based networks and their interworking with the telecommunication networks and MEDIA-COM 2004 are then treated from the viewpoint of the final convergence toward a worldwide global information infrastructure View full abstract»

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  • Open source standards on software process: a practical application

    Page(s): 116 - 123
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    Standards are generally delivered by means of static documents which are difficult to handle and to learn. Although their source text might have an open access, they do not offer an open source environment which effectively supports their assimilation, comprehension, and use. To achieve this goal, standards regulating the software process should be delivered in different “workable” formats to allow users to immediately start applying them with the support of software tools and methodologies View full abstract»

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Aims & Scope

IEEE Communications Magazine covers all areas of communications such as lightwave telecommunications, high-speed data communications, personal communications systems (PCS), ISDN, and more.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Sean Moore
Centripetal Networks