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Personal Communications, IEEE

Issue 3 • Date June 1998

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Displaying Results 1 - 8 of 8
  • Wireless Communication: The Interactive Multimedia CD-ROM

    Page(s): 8 - 9
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    Freely Available from IEEE
  • Software strategies for portable computer energy management

    Page(s): 60 - 73
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    Limiting the energy consumption of computers, especially portables, is becoming increasingly important. Thus, new energy-saving computer components and architectures have been and continue to be developed. Many architectural features have both high-performance and low-power modes, with the mode selection under software control. The problem is to minimize energy consumption while not significantly impacting the effective performance. We group the software control issues as follows: transition, load-change, and adaptation. The transition problem is deciding when to switch to low-power, reduced-functionality modes. The load-change problem is determining how to modify the load on a component so that it can make further use of its low-power modes. The adaptation problem is determining how to create software that allows components to be used in novel, power-saving ways. We survey implemented and proposed solutions to software energy management issues created by existing and suggested hardware innovations View full abstract»

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  • Radio frequency integrated circuit technology for low-power wireless communications

    Page(s): 11 - 19
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    The radio frequency portion of a handheld wireless communications device represents a significant fraction of the battery drain of the overall unit. As a result, an intensive effort is underway on a worldwide basis to minimize the overall radio frequency power requirements. This effort has proceeded on many fronts, with the best work drawing on the multidisciplinary efforts of researchers in the communications systems, circuit design, and semiconductor technology areas. This article summarizes the significant technological challenges to the realization of low-power radio frequency circuits, and follows with a discussion of the research programs that have been put in place to address these challenges. RF transceiver architectures are discussed in particular together with performance aspects View full abstract»

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  • Coding and modulation under power constraints

    Page(s): 32 - 39
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    An issue arising at the physical layer in digital wireless transmission is the choice of the coding/modulation scheme taking into account the availability of a limited energy source. This article is devoted to a description of the rationales behind this choice. As the latter depends on the channel model, we examine four of these, namely, the Gaussian channel, the independent-fading channel, the block-fading channel, and a channel where the transmission quality is limited by interference rather than by noise. Code selection and power-allocation strategies are discussed View full abstract»

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  • Wireless local loop: architecture, technologies and services

    Page(s): 74 - 80
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    Wireless local loop (WLL) provides two-way calling services to the stationary or “fixed” users, which is intended to replace its wireline counterpart. Today, there are almost 100 WLL systems (either trials or commercial systems). This article describes the WLL architecture, the WLL technologies, WLL service descriptions, and some examples of WLL products View full abstract»

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  • Toward power-sensitive network architectures in wireless communications: concepts, issues, and design aspects

    Page(s): 50 - 59
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    Transmitter power control can be used to concurrently achieve several key objectives in wireless networking, including minimizing power consumption and prolonging the battery life of mobile nodes, mitigating interference and increasing the network capacity, and maintaining the required link QoS by adapting to node movements, fluctuating interference, channel impairments, and so on. Moreover, power control can be used as a vehicle for implementing on-line several basic network operations, including admission control, channel selection and switching, and handoff control. We consider issues associated with the design of power-sensitive wireless network architectures, which utilize power efficiently in establishing user communication at required QoS levels. Our focus is mainly on the network layer and less on the physical one. Besides reviewing some of the developments in power control, we also formulate some general associated concepts which have wide applicability to wireless network design. A synthesis of these concepts into a framework for power-sensitive network architectures is done, based on some key justifiable points. Various important relevant issues are highlighted and discussed, as well as several directions for further research in this area. Overall, a first step is taken toward the design of power-sensitive network architectures for next-generation wireless networks View full abstract»

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  • Low-power signal processing system design for wireless applications

    Page(s): 20 - 31
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    Our ability to work with most multimedia data has been confined to a wired environment, requiring both the data source and the receiver to be physically connected to a power supply and a wired communication link. This article describes the design principles applicable to wireless signal processing systems, using a portable video-on-demand system as an example. The discussion focuses on both the algorithm and circuit design techniques developed for implementing a low-power video compression/decompression system at power levels that are two orders of magnitude below existing solutions. This low-power video compression system not only provides a compression efficiency similar to industry standards, but also maintains a high degree of error tolerance to guard against the transmission errors often encountered in wireless communication View full abstract»

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  • Power-saving mechanisms in emerging standards for wireless LANs: the MAC level perspective

    Page(s): 40 - 48
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    This article provides an overview of mechanisms used for power saving in the upcoming standards for wireless LANs: IEEE 802.11 and ETSI RES 10 HIPERLAN. Power saving on the MAC level is addressed by these standards in a quite different way. We outline the main features of the mechanisms in both standards in terms of power saving. In addition we present simulation studies of the power-saving mechanism in ad hoc configurations of IEEE 802.11 networks, which demonstrate the optimization potential and some performance trade-offs quantitatively View full abstract»

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Aims & Scope

This Magazine ceased publication in 2001. The current retitled publication is IEEE Wireless Communications.

Full Aims & Scope