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Network, IEEE

Issue 5 • Date Sept.-Oct. 1994

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Displaying Results 1 - 5 of 5
  • Multimedia nomadic services on today's hardware

    Page(s): 12 - 21
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2251 KB)  

    Describes nomadic computing services built with currently available hardware and used on a daily basis by a small community of users. This environment consists of applications accessing pagers, facsimile, answering machines, telephone lines, speech synthesis, and digital recording and playback. Its key contributions are the integration of multiple media into a cohesive nomadic information infrastructure and a graceful transition from desktop to nomadic locales. This integration is at the service and user interface levels; the point of the article is that one can successfully prototype a suite of multimedia nomadic services by cobbling together applications, shellscripts, and disparate hardware components. The nomadic services make strong use of speech to provide remote access over ordinary telephone lines to a suitable set of tasks that users normally perform at the desktop. The authors place particular emphasis on communication, spanning voice as well as text and facsimile messaging. In addition these services provide personal information management, remote database access, and short-term information caching. The link between nomadic and desktop computing also changes office applications-nomadic services utilize demanding new media and 24-hour access changes how subscribers use and rely on traditional desktop databases.<> View full abstract»

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  • Disseminating active map information to mobile hosts

    Page(s): 22 - 32
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1725 KB)  

    The article describes an active map service (AMS) that supports context-aware computing by providing clients with information about located-objects and how those objects change over time. The authors focus on the communication issues of disseminating information from an active map server to its clients, and in particular, address how to deal with various overload situations that can occur. Simple unicast callbacks to interested clients work well enough if only a few located-objects are moving at any given time and only a few clients wish to know about any given move. However, if many people are moving about in the same region and many clients are interested in their motion, then the AMS may experience overload due to the quadratic nature of the communications involved. This overload affects both the server as well as any slow communications links being used. Mobile distributed computing enables users to interact with many different mobile and stationary computers over the course of the day. Navigating a mobile environment can be aided by active maps that describe the location and characteristics of objects within some region as they change over time.<> View full abstract»

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  • User profile identification in future mobile telecommunications systems

    Page(s): 33 - 39
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1808 KB)  

    A UMTS (Universal Mobile Telecommunications System) user profile denotes in which domains and under which conditions a specific service is available to a user. As the research work on UMTS is still in progress, new requirements for the user profile and its management are likely to be set. This article discusses the UMTS user profile identification issues. The authors introduce first the concept of user profile and the UMTS entities related to it. Then, the user profile is described and its management requirements are discussed followed by the description of two scenarios proposed for the user profile identification. Finally, the authors give a comparison of the two scenarios and their concluding remarks.<> View full abstract»

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  • Teletraffic considerations for widespread deployment of PCS

    Page(s): 40 - 49
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2146 KB)  

    To offer personal communication services (PCS) to large segments of the population, sophisticated digital radio access techniques and extensive use of "Advanced Intelligent Network" services of public wireline networks will be required. To accommodate wireless access on such a wide scale, a broad range of challenging new teletraffic problems will need to be solved. In this article the authors give a brief, high-level overview of some of the important teletraffic issues that they believe will need to be addressed to support widespread deployment of PCS. Much more work is needed in order to refine our understanding of these issues, to prioritize specific problems, and to solve them. The purpose of this article is not to provide an exhaustive list of all PCS teletraffic issues, but rather to stimulate discussion of these problems.<> View full abstract»

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  • Medium access control of wireless LANs for mobile computing

    Page(s): 50 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (4735 KB)  

    To provide high-speed seamless services for mobile computing, an effective medium access control capable of dealing with mobility issues in multicell wireless local area networks is needed. The physical layers discussed include direct sequence spread spectrum (DS-SS), frequency hopped spread spectrum (FH-SS), and diffuse infrared. Both spread spectrum transmissions are in the 2.4 to 2.4835 GHz ISM band, according to FCC part 15.247.<> View full abstract»

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Aims & Scope

IEEE Network covers topics which include: network protocols and architecture; protocol design and validation; communications software; network control, signaling and management; network implementation (LAN, MAN, WAN); and micro-to-host communications.

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Meet Our Editors

Editor-in-Chief
Xuemin (Sherman) Shen, PhD
Engineering University of Waterloo