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Communications Magazine, IEEE

Issue 2 • Date Feb. 2005

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Displaying Results 1 - 25 of 31
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  • Meetings and conferences

    Page(s): 6 - 7
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  • IEEE Optical Communications

    Page(s): S1 - S2
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  • Mobile IPv6: mobility in a wireless internet [Book Review]

    Page(s): 8
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    Freely Available from IEEE
  • IEEE Communications Magazine

    Page(s): 1
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    Freely Available from IEEE
  • Table of contents

    Page(s): 2 - 4
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    Freely Available from IEEE
  • Approaches to spectrum sharing

    Page(s): 10 - 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB) |  | HTML iconHTML  

    Many complain about severe spectrum shortage. The shortage comes from outdated spectrum policies that allows for little sharing. Regulators have granted licenses that offer exclusive access to the spectrum. When these licensees are not transmitting, the spectrum sits idle. A new technology regarding spectrum shortage enables more spectrum sharing that unleashes innovative products and services, provided that we adopt the appropriate spectrum policies. Two camps are pushing for extreme reform, one for "property rights" and the other for "spectrum commons". This article presents concepts underlying the "property" and "commons" debate, clarifies options for spectrum reform, and describes the trade-offs of spectrum sharing View full abstract»

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  • Conference calendar

    Page(s): 14 - 16
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    Freely Available from IEEE
  • New products

    Page(s): 20
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    Freely Available from IEEE
  • CommuniCrostic puzzle

    Page(s): 22
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    Freely Available from IEEE
  • OFC/NFOEC 2005 (Reaching the Entire Spectrum of Optical Communications)

    Page(s): S6 - S8
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    Freely Available from IEEE
  • Bandwidth allocation for multiservice access on EPONs

    Page(s): S16 - S21
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (542 KB) |  | HTML iconHTML  

    Ethernet passive optical networks are a low-cost high-speed solution to the bottleneck problem of the broadband access network. A major characteristic of EPONs is the shared upstream channel among end users, mandating efficient medium access control to facilitate statistical multiplexing and provision multiple services for different types of traffic. This article addresses and provides an overview of the upstream bandwidth allocation issue for multiservice access provisioning over EPONs, and proposes an algorithm for dynamic bandwidth allocation with service differentiation. Based on the multipoint control protocol (MPCP) and bursty traffic prediction, our algorithm enhances QoS metrics such as average frame delay, average queue length, and frame loss probability over other existing protocols View full abstract»

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  • Addressing challenges in serial 10 Gb/s multimode fiber enterprise networks

    Page(s): S22 - S28
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (536 KB) |  | HTML iconHTML  

    As the number of networked computer devices connected within local area networks increases, the aggregation requirements of the optical fiber backbone within these networks are also increased. This article highlights the challenges - and a possible solution - to migrating data communications networks to higher data rate capability, while in parallel cost effectively supporting the existing fiber infrastructure View full abstract»

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  • The first hot pluggable 2.5 Gb/s DWDM transceiver in an SFP form factor

    Page(s): S29 - S31
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (705 KB) |  | HTML iconHTML  

    For the first time, a hot pluggable 2.5 Gb/s DWDM transceiver with 100 GHz spacing in an SFP form factor has been presented. We demonstrate transmit wavelength drift of plusmn9 pm and optical output power stability of 0.2 dB over an operating case temperature range of -5degC to 70 degC. The minimum receive sensitivity was -33.2 dBm for back-to-back, -32.6 dBm after transmission over 80 km of standard SMF, and -28 dBm for an OSNR level of 16 dB at a BER of 1 times 10-10 View full abstract»

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  • Interference-free broadband single- and multicarrier DS-CDMA

    Page(s): 68 - 73
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (593 KB) |  | HTML iconHTML  

    The choice of the direct sequence spreading code in DS-CDMA predetermines the properties of the system. This contribution demonstrates that the family of codes exhibiting an interference-free window (IFW) outperforms classic spreading codes, provided that the interfering multi-user and multipath components arrive within this IFW, which may be ensured with the aid of quasi-synchronous adaptive timing advance control. It is demonstrated that the IFW duration may be extended with the advent of multicarrier DS-CDMA proportionately to the number of subcarriers. Hence, the resultant MC DS-CDMA system is capable of exhibiting near-single-user performance without employing a multi-user detector. A limitation of the system is that the number of spreading codes exhibiting a certain IFW is limited, although this problem may be mitigated with the aid of novel code design principles View full abstract»

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  • CS-OFDMA: a new wireless CDD physical layer scheme

    Page(s): 74 - 79
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (518 KB) |  | HTML iconHTML  

    A proposed new innovative wireless CDD physical layer scheme for 4G called CS-OFDMA is introduced. Code spreading uses a set of smart codes with its meritorious properties, which can eliminate multipath and multiuser interferences. The same number of smart codes applied repeatedly in each subcarrier of OFDMA is used to increase the number of traffic channels. It takes advantage of attributes of both CDMA and OFDMA toward a simpler and more spectrally efficient system applied in a CDD system [(W.C.Y. Lee, Mar 2002), (W.C.Y. Lee, 2003)] View full abstract»

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  • Ultra-wideband for multiple access communications

    Page(s): 80 - 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (524 KB) |  | HTML iconHTML  

    Ultra-wideband wireless communications techniques have many merits, including an extremely simple radio that inherently leads to low-cost design, large processing gain for robust operations in the presence of narrowband interference, covert operations, and fine time resolution for accurate position sensing. However, there are a number of challenges in UWB receiver design, such as capturing multipath energy, intersymbol interference especially in a non-line-of-sight environment, and the need for high-sampling-rate analog-to-digital converters. In this article, we provide a comprehensive review of UWB multiple access and modulation schemes, and their comparison with narrowband radios. We also outline the issues with UWB signal reception and detection, and explore various suboptimal low-complexity receiving schemes View full abstract»

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  • A time-orthogonal CDMA high-speed uplink data transmission scheme for 3G and beyond

    Page(s): 88 - 94
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (509 KB) |  | HTML iconHTML  

    In 3G systems, the achievable data rates and capacity on the uplink are much smaller than the downlink data rates and capacity due to the nonorthogonal nature of the CDMA uplink. In this article, we present a new time-orthogonal CDMA approach called high-speed uplink data burst transmission mode. The concept is based on slot-synchronized slot-orthogonal transmissions whereby high-speed data transmissions take place in slots orthogonal to the slots used for physical layer control signaling and low-data-rate transmission such as resource requests. Using this approach, very high data rates and capacity are achieved during data burst transmission because of the availability of high signal-to-interference-plus-noise ratio, resulting from the orthogonal nature of the transmissions. Simulation results show that the uplink spectral efficiency of the proposed scheme is approximately four times better than that achieved with the existing 3G systems View full abstract»

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  • Perspectives for present and future CDMA-based communications systems

    Page(s): 95 - 100
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB) |  | HTML iconHTML  

    In this article the main boosters of future CDMA communication systems are presented and described in order to highlight the ways to cope with the more challenging requirements of future systems and services. Particular attention is devoted to the inherent weak points of CDMA systems and detection techniques that can be used to overcome their impairments. Moreover, high-data-rate transmissions in wireless channels require proper link adaptation techniques; these are thoroughly described as well. Finally, the last part of this article focuses on the design of suitable protocol strategies for new heterogeneous multimedia packet services characterized by strict QoS requirements View full abstract»

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  • A high-performance MIMO OFDM wireless LAN

    Page(s): 101 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (564 KB) |  | HTML iconHTML  

    Tremendous consumer interest in multimedia applications is fueling the need for successively higher data rates in wireless networks. Data rates in wireless wide area networks are limited by the need to address wide coverage, vehicular mobility, and the limitations of licensed spectrum. Thus, data rates in WWANs continue to lag advances in wireless local area networks by orders of magnitude. There are valuable lessons to be learned from the design of WLANs that provide data rates in excess of hundreds of megabits per second. Several technologies are instrumental in enabling the future of high-performance WWANs, including multiple transmit and receive antennas, OFDM, closed loop transmission control, and low-latency MAC operation. We describe a MIMO WLAN design and prototype that exploits these attributes to provide data rates in excess of 200 Mb/s above the MAC View full abstract»

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  • A tutorial on multiple access technologies for beyond 3G mobile networks

    Page(s): 110 - 117
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (543 KB) |  | HTML iconHTML  

    In this article, some fundamental technical concepts of the main multiple access schemes for wireless mobile systems are reviewed, and a path for the development of appropriate multiple access technologies for next-generation mobile networks, or so-called beyond 3G (B3G), is established. We first review the multiple access technologies in second- and third-generation wireless cellular systems from historical and technical points of view. This review is followed by a novel formulization of the multiple access schemes through mathematical expressions that could simplify the process of development of new multiple access schemes for B3G wireless cellular systems. We then list the most important features of multiple access schemes in 3G mobile systems. Finally, we conclude the article by reviewing the most promising multiple access technologies for B3G mobile cellular systems View full abstract»

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  • MIMO MC-CDMA communications for future cellular systems

    Page(s): 118 - 124
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (531 KB) |  | HTML iconHTML  

    We propose an efficient multiple-input multiple-output concept based on space-time turbo coded modulation and layered spatial multiplexing architectures for cellular multicarrier code-division multiple access systems. We design appropriate receiver algorithms, and compare their performance to competing schemes in a single-cell system. We then evaluate the performance of the scheme in a seven-cell system with universal frequency reuse. The proposed MIMO scheme improves throughput significantly compared to the corresponding single-antenna communications even in the presence of spatial correlation 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