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Communications Magazine, IEEE

Issue 12 • Date Dec. 1997

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Displaying Results 1 - 13 of 13
  • 1997 Index IEEE Communications Magazine Vol. 35

    Publication Year: 1997 , Page(s): 150 - 168
    Cited by:  Papers (2)
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    Freely Available from IEEE
  • Hardware implementation of fair queuing algorithms for asynchronous transfer mode networks

    Publication Year: 1997 , Page(s): 54 - 68
    Cited by:  Papers (29)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2048 KB)  

    Providing quality-of-service guarantees in both cell- and packet-based networks requires the use of a scheduling algorithm in the switches and network interfaces. These algorithms need to be implemented in hardware in a high-speed switch. The authors present a number of approaches to implement scheduling algorithms in hardware. They begin by presenting a general methodology for the design of timestamp-based fair queuing algorithms that provide the same bounds on end-to-end delay and fairness as those of weighted fair queuing, yet have efficient hardware implementations. Based on this general methodology, the authors describe two specific algorithms, frame-based fair queuing and starting potential-based fair queuing, and discuss illustrative implementations in hardware. These algorithms may be used in both cell switches and packet switches with variable-size packets. A methodology for combining a traffic shaper with this class of fair queuing schedulers is also presented for use in network interface devices, such as an ATM segmentation and reassembly device View full abstract»

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  • Digital signal processors in cellular radio communications

    Publication Year: 1997 , Page(s): 22 - 35
    Cited by:  Papers (13)  |  Patents (4)
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    Contemporary wireless communications are based on digital communications technologies. The recent commercial success of mobile cellular communications has been enabled in part by successful designs of digital signal processors with appropriate on-chip memories and specialized accelerators for digital transceiver operations. This article provides an overview of fixed point digital signal processors and ways in which they are used in cellular communications. Directions for future wireless-focused DSP technology developments are discussed View full abstract»

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  • Evolution phases to an ultra broadband access network: results from ACTS-PLANET

    Publication Year: 1997 , Page(s): 72 - 77
    Cited by:  Papers (9)
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    This article presents a new systematic approach to network evolution, considering access and core network evolution as a whole. The evolution phases are designed to fulfill the following evolution requirements. Each phase provides an incentive to the operator and the customer by providing more functionality, higher bit rates, or reduced cost. The phases are realistic for low penetration and match the growth of infrastructure to the gradual growth of the demand. Technologies are independently introduced in the access and core networks depending on demand. The evolution scenario starts with ADSL and evolves toward ultra-broadband access networks based on SuperPON architectures. The new enhanced APON architecture is introduced as a practical intermediate evolution phase. For the first time, the principle of segmentation is applied to APONs/SuperPONs to enable gradual growth in number of subscribers and network capacity. Optical channels and wavelength-division multiplexing are introduced in the core network View full abstract»

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  • Wavelet and subband transforms: fundamentals and communication applications

    Publication Year: 1997 , Page(s): 104 - 115
    Cited by:  Papers (17)  |  Patents (3)
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    Subband and wavelet transforms have been a subject of great interest, especially in the fields of signal processing and applied mathematics. This article presents a tutorial on this subject, emphasizing the fundamentals and the reason for its success, importance, and potential. Subband and wavelet transform applications in communications are also reviewed. These application areas include interference excision, spread spectrum codes based on subband transform bases, CDMA, and discrete multitone transceivers View full abstract»

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  • Broadbandloop: a full-service access network for residential and small business users

    Publication Year: 1997 , Page(s): 88 - 93
    Cited by:  Papers (10)  |  Patents (2)
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    There is a worldwide effort to define a full-service access network. The Broadbandloop project was formed by a European consortium funded by the European Union with the objective of defining a strategy for evolution from a narrowband voice and data network to a broadband network. The project is defining a system concept based on new innovative PON technology, which enables fiber to cost effectively penetrate close to the customer, and VDSL technology for transmission over twisted copper pairs. The system concept is validated in field trials in Denmark, Portugal, and Poland. The article describes the different requirements for a full-service access network, the system concept, and technologies developed. Results from modeling of broadband traffic and the corresponding bandwidth are given. The cost effectiveness of using new optical fiber vs. reusing existing telephone copper plant has been evaluated, and results from these studies are presented View full abstract»

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  • Recent advances in RF integrated circuits

    Publication Year: 1997 , Page(s): 36 - 43
    Cited by:  Papers (11)  |  Patents (1)
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    This article describes recent activities in the area of RF integrated circuits. First, transceiver architectures developed for cellular and cordless telephone standards are presented. Next, the choice of device technology is discussed, and the design of building blocks such as low-noise amplifiers and mixers, oscillators, and power amplifiers is described. Last, some of the emerging applications of RF circuits and their implications for the design are considered View full abstract»

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  • The Pan American Cable System

    Publication Year: 1997 , Page(s): 134 - 140
    Cited by:  Papers (1)  |  Patents (1)
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    The Pan American Cable System, when completed in September 1998, will provide high capacity international telecommunication services between South America and the rest of the world. Pan American will be a cost effective 7300 km trunk and branch undersea cable system with landings in Chile, Peru, Ecuador, Panama, Colombia, Venezuela, Aruba, and the United States. It will be configured into four logical rings that will automatically protect traffic in the rest of the network should a fault occur in any branch. Initially planned to operate at 2.5 Gb/s on a single wavelength, the rings can be stacked using wavelength division multiplexing to increase capacity as demand for international services to the region grows. A highly sophisticated network management system will operate, administer, and maintain the entire network from a centralized, secure location View full abstract»

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  • Low-cost scalable switching solutions for broadband networking: the ATLANTA architecture and chipset

    Publication Year: 1997 , Page(s): 44 - 53
    Cited by:  Papers (45)  |  Patents (9)
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    The ATLANTATM switching architecture has the following distinguishing characteristics: (1) is nonblocking, (2) scales modularly over a wide range of switching and buffering capacities using commonly available implementation technology, (3) achieves high buffer utilization while using distributed buffers, (4) has low complexity, and (5) provides a clear path for future growth in features. The ATLANTA architecture uses an innovative structure with ingress and egress buffers, where selective backpressure is applied from the fabric to the ingress cards. Selective backpressure makes the buffers in the ingress cards act as an extension of the output buffers in the fabric, achieving "sharing" of the distributed buffers and buffer utilization comparable with a centralized shared-memory switch. The advantage is that the majority of the buffers are in the ingress and egress port cards, and are implemented using low-cost off-the-shelf memories regardless of the total switching capacity. Different arrangements are possible for the switch fabric. In the smallest configuration, the fabric consists of a single standalone switching module; for larger switching capacities, the fabric is a modular three-stage memory/space/memory (MSM) arrangement. The ATLANTA architecture provides optimal support of multicast traffic. The ATLANTA chipset provides the complete set of building blocks for implementing ATM switches ranging in capacity from 622 Mb/s to 25 Gb/s. The chipset consists of four chips, two devices to be used in the fabric and two in the port cards. The port devices provide full-duplex ingress and egress functionality at 622 Mb/s port rate (plus the overhead due to the local header used internally to the switch). The physical interface to the incoming/outgoing lines supports the UTOPIA II multiplexing standard, and the port devices manage multiplexing/demultiplexing from/to a maximum of 30 subports per port. Although our current implementation of the architecture is targeted primarily to ATM, the principles behind the architecture are more general, and apply to IP switching and routing technologies. View full abstract»

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  • Assessment of alternative transport options for video distribution and retrieval over ATM in residential broadband

    Publication Year: 1997 , Page(s): 78 - 82, 87
    Cited by:  Papers (1)  |  Patents (1)
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    This article analyzes options for transporting CATV distribution, pay-per-view, and video-on-demand over a residential broadband network. It provides clearly tabulated evaluations of video coding alternatives, ATM service category alternatives, ATM adaptation layer alternatives, and methods for dealing with errors and delay. Conclusions are drawn regarding buffer requirements, congestion control, and error control View full abstract»

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  • A primer on turbo code concepts

    Publication Year: 1997 , Page(s): 94 - 102
    Cited by:  Papers (52)  |  Patents (15)
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    The goal of this article is to describe the main ideas behind the new class of codes called turbo codes, whose performance in terms of bit error probability has been shown to be very close to the Shannon limit. In this article, the mathematical measures of a posteriori probability and likelihood are reviewed, and the benefits of turbo codes are explained in this context. Since the algorithms needed to implement the decoders have been well documented by others, they are only referenced here, not described in detail. A numerical example, using a simple concatenated coding scheme, provides a vehicle for illustrating how error performance can be improved when soft outputs from the decoders are used in an iterative decoding process View full abstract»

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  • Overview of multicarrier CDMA

    Publication Year: 1997 , Page(s): 126 - 133
    Cited by:  Papers (721)  |  Patents (91)
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    The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarrier direct sequence CDMA (multicarrier DS-CDMA), and multitone CDMA (MT-CDMA) View full abstract»

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  • Broadband service creation and operations

    Publication Year: 1997 , Page(s): 116 - 124
    Cited by:  Papers (4)
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    Three challenges for deploying broadband services are the time-consuming process of service creation, the interoperability over heterogeneous platforms, and the gap between the needs of service management and the functionalities of network management. We describe a methodology to attack the first two challenges, namely, to simplify the process of service creation and provide a platform-independent framework for service operations. A set of broadband service-independent building blocks (SIBs) are designed and used to create and customize SIB graphs for broadband services. During service running time, the service agent interprets a SIB graph and executes SIB procedures which are all downloaded from the service provider. Web, Java, and CORBA are the technological elements of this methodology. Two examples, video conferencing and video on demand, are given to demonstrate the feasibility of this approach 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
Osman Gebizlioglu
Huawei Technologies