By Topic

Telecommunications Symposium, 1990. ITS '90 Symposium Record., SBT/IEEE International

Date 3-6 Sept. 1990

Filter Results

Displaying Results 1 - 25 of 117
  • SBT/IEEE International Telecommunications Symposium. ITS '90 Symposium Record (Cat. No.90CH2901-7)

    Publication Year: 1990
    Request permission for commercial reuse | PDF file iconPDF (588 KB)
    Freely Available from IEEE
  • Adaptive error control based on type-I hybrid-ARQ protocols

    Publication Year: 1990, Page(s):176 - 180
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    An adaptive error control technique based on the use of type-I hybrid-ARQ protocols is presented. Nonstationary channels are modeled as finite-state Markov chains. The system counts the number of retransmission requests during an observation interval called a frame and, together with knowledge of the code in use and a set of thresholds, estimates the state of the channel. The code which maximizes ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A game theory approach to cooperative and non-cooperative routing problems

    Publication Year: 1990, Page(s):597 - 601
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    Previous work on multiobjective routing takes a system optimization approach to minimize some global objective function. An approach using a game-theoretic formulation is taken. The authors focus on a simple example of two classes which minimize a delay objective. Three cases are considered. The first case (baseline) does global optimization where the routing policies for the two classes are force... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The design of multiplierless digital data transmission filters with powers-of-two coefficients

    Publication Year: 1990, Page(s):425 - 429
    Cited by:  Papers (21)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    An efficient search technique is presented for the design of FIR (finite impulse response) digital transmit and receive matched filters whose coefficients are represented by sums and/or differences of powers-of-two. These filters are ideally suited for custom VLSI implementation since power-of-two multipliers are obtained for free in a dedicated hardware implementation. Thus only a few adders or s... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An approximation algorithm for irregular-ripple filters

    Publication Year: 1990, Page(s):430 - 433
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    A simple formulation is presented for the approximation of low-pass filters with specified number and level of ripples in the passband and stopband. The order of any finite attenuation or transmission zero can be specified as simple or double, and these zeros are not restricted to the jw axis. The method can be used to numerically obtain the characteristic functions of approximations rang... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fairness in network optimal flow control

    Publication Year: 1990, Page(s):590 - 596
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    The authors consider the problem of optimal flow control in a multiclass telecommunications environment where each user (or class) desires to optimize its performance while being `fair' to the other users (classes). The Nash arbitration scheme from game theory is shown to be a suitable candidate for a fair, optimal operation point in the sense that it satisfies certain axioms of fairness and is Pa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multidimensional signaling for intersymbol interference channels

    Publication Year: 1990, Page(s):302 - 306
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    The authors consider the use of multidimensional signaling and block demodulation for digital transmission over intersymbol interference (ISI) channels. As an example, the theory is developed for the unit-memory 1+αz-1 channel. The authors first explain why multidimensional signals should be used over ISI channels by showing how the minimum Euclidean distance and the cuto... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Configuration management for distributed object-oriented applications

    Publication Year: 1990, Page(s):577 - 581
    Cited by:  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB)

    A separate configuration language with associated management mechanisms has been developed. The approach supports the initial structure and placement description of a distributed object-oriented application as well as dynamic configuration changes. Moreover, configuration conditions can be stated and are checked against an actual configuration. The authors describe the configuration language, the ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The double-slot slotted ring protocol (DSR)

    Publication Year: 1990, Page(s):238 - 242
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    The DSR protocol combines a multilevel priority and fairness guarantee mechanism over a destination-release slotted ring. The fairness mechanism ensures fair bandwidth division within each priority level and operates through a distributed reservations algorithm entirely within the media-access control layer. In common with other destination-release slotted rings, the DSR protocol can offer network... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Complexity reduction of CELP coders

    Publication Year: 1990, Page(s):181 - 185
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    The authors propose a modification of the classical CELP (code-excited linear predictive) algorithm in order to reduce its computational complexity and required memory size, while preserving the quality of the reconstructed speech. Rather than performing the individual weighting of each candidate sequence, the authors suggest a global implementation of the vocal tract weighting function at the cod... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance comparison of four MAC protocols for integrated MANs

    Publication Year: 1990, Page(s):104 - 112
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (644 KB)

    The performance of four different MAC (medi access control) sublayer protocols proposed for applications in extended local area networks and/or metropolitan area network (MANs) integrating different types of traffic are compared. The four protocols are Expressnet, Fasnet, QPSX (or distributed queue dual bus-DQDB), and FDDI-II (fiber distributed data interface II). Performance results in terms of a... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An assessment of the performance of slant-path attenuation prediction methods in tropical and equatorial regions

    Publication Year: 1990, Page(s):233 - 237
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    As the demands for larger capacity and new satellite services increase, so does the importance of the problem of slant-path attenuation prediction at frequencies above 10 GHz. The authors present a comparison between the attenuation predicted by nine of the currently available methods, using point rainfall data measured at four Brazilian locations, and the attenuations actually obtained from concu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of the quantization effects of LMS complex algorithm in digital adaptive filters

    Publication Year: 1990, Page(s):307 - 311
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB)

    A novel theoretical formulation is developed for the errors due to the digital implementation of the LMS algorithm in adaptive filters. An analytic expression is determined for the mean-square error at the output of the adaptive filter. This expression is valid both for transient conditions and for the steady state. The convergence conditions of the algorithm are studied and a very simple and usef... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of the bit error probability in a direct sequence spread spectrum system with code division multiple access

    Publication Year: 1990, Page(s):282 - 286
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    After a short introduction to the direct-sequence spread-spectrum system under study and a description of the model used for reception, the code sequences are selected. These sequences, obtained from Gold code sequences with m=9, are selected using an empirical method which tries to minimize the influence of one code sequence upon others. After selecting the code sequences the bit error p... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance analysis of all-digital PSK carrier tracking loops

    Publication Year: 1990, Page(s):529 - 534
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    The performance of PSK (phase shift keying) carrier-tracking loops having a structure suitable for an all-digital implementation is analyzed. The analysis is based on the stochastic difference equation that governs the evolution of the loop phase error sequence. General expressions for the phase error variance, obtained through a linear analysis of the loop difference equation, are derived. An app... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new approach for enhancing the throughput capability of a synchronous bus LAN

    Publication Year: 1990, Page(s):243 - 249
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    An original media access protocol called CAST (counting access to synchronous time slots) is proposed. This protocol can be implemented over a synchronous bus local area network (LAN). CAST uses a simple algorithm by which each station can recognize its turn of access by counting either the number of data packets or the number of idle pulses sent from all preceding stations. The throughput versus ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A comparison between experimentally observed and simulated behaviors of XPD in frequency-reuse LOS links

    Publication Year: 1990, Page(s):217 - 221
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    A simulation model of multipath propagation is used to characterize the relationship between the cross-polarization discrimination and the co-polar attenuation in frequency-reuse line-of-sight links. The behavior of several links are then simulated, and the results are compared with measurements, to test the prediction capability of the model View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fiber optics use in digital integrated telecommunication systems in mining works

    Publication Year: 1990, Page(s):468 - 472
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (268 KB)

    The advantages of fiber optic applications in mining works are examined, the main specific transmission applications are studied, and an integrated digital network project is presented. The integrated digital network permits the transmission of a great variety of signals such as telephony, data, and video from and to the mining processes. The network uses optical fibers as the medium of transmissi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Vector quantization with size-constrained codebooks

    Publication Year: 1990, Page(s):186 - 190
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    An algorithm for calculating lower bounds to the performance of all size-constrained vector quantizers has been derived earlier. Applications to the AR(1) source have shown that these lower bounds are very close to the actual rate-distortion curves, even for small sizes of the output alphabet. In this algorithm, however, the codebook changes with rate. In a number of applications it is desirable t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parallel protocol implementations for high speed networks

    Publication Year: 1990, Page(s):260 - 264
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    The development of high speed networks with data rates of 100 Mbit/s and more as well as the design of advanced applications imposes new requirements on the performance of network nodes. The author describes an approach to overcome the upcoming processing bottlenecks of communication protocols. The approach is based on the use of multiprocessor architectures. Several parallel concepts inside netwo... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the design of a high performance ATM metropolitan area network

    Publication Year: 1990, Page(s):503 - 508
    Cited by:  Papers (1)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (580 KB)

    Some aspects of the design of high-performance ATM (asynchronous transfer mode)-compatible MANs (metropolitan area networks) are discussed. In particular, throughput and fairness parameters are examined. As far as fairness is concerned, a merit figure is proposed, and an evaluation procedure is presented. A general approach to cope with the above-mentioned aspects is discussed and, as a proposed s... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance evaluation of a distributed reservation TDMA to access an ATM user-oriented satellite system

    Publication Year: 1990, Page(s):82 - 86
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    The authors examine a distributed reservation TDMA (time division multiple access) algorithm for dynamic handling of bursty traffic in an ATM (asynchronous transfer mode) multiservice user-oriented satellite network. Major aspects associated with the achievement of efficiency, robustness, and fairness are high-lighted. A performance evaluation carried out by means of an accurate simulation model i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • PC workstation for Ethernet monitoring and management

    Publication Year: 1990, Page(s):568 - 570
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    The authors present a monitoring and management workstation for IEEE 802.3 networks (Ethernet) based on a PC-AT. The monitor performs traffic analysis, detects active machines in the network, maintains a network database with information regarding network topology and machines, filters specific packets or protocols, and can also work as a traffic generator. The system has a user friendly interface... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Major performance characteristics of the DQDB MAC protocol

    Publication Year: 1990, Page(s):113 - 120
    Cited by:  Papers (6)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (588 KB)

    Major performance characteristics of the DQDB (distributed queue dual bus) MAC (medium access control) protocol in different traffic environments are shown. First, the author addresses throughput unfairness in the default protocol during heavy load periods, and the fact that under such a condition the vital priority mechanism cannot be guaranteed to be effective. He then focuses on the optional ba... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Queuing analysis of a shared buffer strategy for transport-layer connections

    Publication Year: 1990, Page(s):166 - 171
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    The performance of transport-layer connections with buffer sharing is investigated. The authors consider the scenario of multiple sender hosts and a single receiver host which are connected through a transport network. Application-layer processes in the sender hosts generate messages which are transferred to a peer process in the receiver host. Messages are transferred over window flow-controlled ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.