By Topic

Communications, IEEE Transactions on

Issue 9 • Date September 1980

Filter Results

Displaying Results 1 - 25 of 45
  • [Front cover and table of contents]

    Publication Year: 1980 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (327 KB)  
    Freely Available from IEEE
  • Preface: Military communications - An overview of the special issue

    Publication Year: 1980 , Page(s): 1441 - 1444
    Save to Project icon | Request Permissions | PDF file iconPDF (533 KB)  
    Freely Available from IEEE
  • [Back cover]

    Publication Year: 1980 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (391 KB)  
    Freely Available from IEEE
  • Cost Implications for Survivability of Terrestrial Networks Under Malicious Failure

    Publication Year: 1980 , Page(s): 1668 - 1674
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB)  

    Protection against malicious failure is a very important issue in many network applications. While no general theory is easily developed, the following general statement emerges from any analysis: the combined link cost (topology) to guard against such failure is much higher than to protect against random failure. In this paper we first define precisely the concept of malicious failure and immediately show the severe cost implications. To constrast this a summary of the major results in random failure is provided. We then manually carry out some survivability computations on networks on a small number of nodes; we also address the issue of partial knowledge. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Integrated Distributed Control Structure for Global Communications

    Publication Year: 1980 , Page(s): 1505 - 1515
    Cited by:  Papers (5)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1064 KB)  

    The worldwide communications resources of the Defense Communications System (DCS) are controlled by a multilevel control complex, with distribution of control functions among many control facilities. The control structure is going through substantial changes, driven by considerations of reliability, survivability, crisis management capability, and of course, cost. This paper introduces the control structure, the ongoing and programmed improvements for the control capabilities, and how the Automated Technical Control (ATEC) equipments will form the basis of a distributed, processor based communications control utility. Finally, the unique features of the Real Time Adaptive Control System (RTACS) for the third generation Defense Satellite Communications System (DSCS) will be described, along with the integration of RTACS into the distributed global control structure. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Capacity Allocation and Reservation in Common-User Satellite Communications Systems with a Reconfigurable Multiple-Beam Antenna and a Nonlinear Repeater

    Publication Year: 1980 , Page(s): 1681 - 1692
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1088 KB)  

    The use of a flexible transmit multiple-beam antenna (MBA) connected to a nonlinear satellite repeater is investigated as a means of adaptive resource allocation in a common-user communications network comprising different types and deployments of earth terminals. Such a general-purpose network is typically encountered in hybrid systems architectures supporting international command and control functions, e.g., in defense alliances or in maritime mobile services shared by several national administrations. A priori strategies for the adjustment of MBA gains and carrier powers are determined such that the performance of an FDMA or CDMA network is optimized (in terms of the chosen strategy), taking account of realistic uplink, repeater, and downlink noise contributions. Simple formulas are derived for evaluation and comparison of different repeater and antenna designs in the various possible operational scenarios; these formulas obviate the need for detailed a priori allocation of all link parameters in the assessment of network traffic capacity, fading margins, etc. Numerical studies of three hypothetical network scenarios are included to illustrate the increased significance of nonlinear effects (such as intermodulation noise) in any satellite system in which a flexible transmit MBA can enhance the performance. This emphasizes the need for careful planning and operational control of such flexible systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Analysis of Meteor Burst Communications for Military Applications

    Publication Year: 1980 , Page(s): 1591 - 1601
    Cited by:  Papers (41)  |  Patents (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1128 KB)  

    This paper presents a methodology for the design and analysis of meteor burst communication systems, with special emphasis on system characteristics of importance to military applications (intercept resistance, jam resistance, nuclear survivability, and encryption considerations). Using stochastic models for the meteor burst process, expressions for the average throughput and average message waiting time are derived. These equations are used to estimate the anticipated performance of several kinds of meteor burst communications systems m a number of military applications ranging from data collection from unattended sensors to facsimile transmission. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Error Performance Measurements on an Experimental 12/14 GHz Satellite Link

    Publication Year: 1980 , Page(s): 1779 - 1784
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (600 KB)  

    This correspondence presents results related to measurmg the error performance of an experimental 12/14 GHz satellite link established between Carleton University, Ottawa, Canada, and NASA Ames Research Center, California, in 1976-1977. The measurements were performed on a 9.6 kbit/s voiceband data channel which supported the continuous synchronous transmission of fixed length frames (composite packets). The results include measurements of packet error rate versus uplink power settings under various atmospheric conditions, densities of packet error-free interval lengths, within-packet error statistics, and propagation delay variations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some Aspects of the Fast Karhunen-Loeve Transform

    Publication Year: 1980 , Page(s): 1773 - 1776
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    A few important properties of the fast Karhunen-Loeve transform (FKLT) proposed by Jain [3] are discussed. The purpose here is to emphasize the role of the boundary conditions upon which the entire theory is based. The effects of the zero boundary conditions are also discussed. It is argued that the transform is not as efficient as it might appear when used in bit rate reduction. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Three Typical Blocking Aspects of Access Area Teletraffic

    Publication Year: 1980 , Page(s): 1662 - 1667
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (664 KB)  

    In this paper, an effort is made to represent the military access area grade of service (i.e., probability of blocking) in a more realistic way than before. The circuit switching process is structured into three representative contention phases. The three phases are analytically tractable and are rather typical in existing military networks. All three phases apparently have service properties not accurately described by the conventional Engset, Erlang, and other classical models. Their blocking probabilities also differ from those predicted by the classical models. Given an access area network, the three blocking models may be applied individually or in a variety of combinations. The paper demonstrates several applications to typical access area telephony. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Application of Charge-Coupled Devices to Spread-Spectrum Systems

    Publication Year: 1980 , Page(s): 1693 - 1705
    Cited by:  Papers (9)  |  Patents (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1120 KB)  

    The application of charge-coupled device (CCD) technology to spread-spectrum systems is presented. In particular, CCD pseudonoise matched filters and recursive integrators are described functionally and as semiconductor devices. Then, applications to various modulation formats are considered in terms of integrated circuit architecture. Acquisition and synchronization for directsequence and hybrid frequency-hopping spread-spectrum systems are also covered. Finally, random time-division multiple-access acquisition and data demodulation are considered. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computer Security and Networking Protocols: Technical Issues in Military Data Communications Networks

    Publication Year: 1980 , Page(s): 1472 - 1477
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    Two problems which limit information sharing among computers are fear of compromise of sensitive data (through accidental disclosure or theft), and designing networking protocols which support effective interconnection of heterogeneous systems. These problems are presented in the context of defense systemsapproaches to their solution are discussed-and issues and open questions which must be addressed in the future are identified. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Survivable Network of Ground Relays for Tactical Data Communications

    Publication Year: 1980 , Page(s): 1616 - 1624
    Cited by:  Papers (2)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1056 KB)  

    The rationale and a preliminary design concept are presented for a new mobile ground-to-ground communications system to support tactical command and control. Survivability is attained through high connectivity, antenna directivity, and spread-spectrum signals. Each node of the proposed network is equipped with a circular cylindrical array antenna capable of steering a narrow beam in the direction of one of its several neighbors. A single transceiver operates half-duplex m a flexible time-division format among the multiple links at a node. Each link uses a unique pseudonoise code, and the network as a whole employs code-division multiple access. Mobility and survivability are enhanced because a single equipment supports multiple links while providing the benefits of high antenna gain and directivity. Network entry and synchronization schemes are considered. System parameters are defined and link power budgets for signal-to-jammer and signal-to-noise ratios are calculated. Implementation prospects are addressed drawing on technology developments in antenna arrays, surface-acoustic wave signal processing, and adaptive routing in packet networks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimum Deployment of Communications Relays in an Interference Environment

    Publication Year: 1980 , Page(s): 1608 - 1615
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (736 KB)  

    The use of communications relays is examined as a means of improving the operation of line-sight-links in an interference or jamming environment. Expressions are derived that define optimum relay locations and the number of relays. These relationships are functions of the system and interference parameters, as well as of the link and interference source geometry. Bounds on flight path orbits of airborne relays are also defined. Backlink operation with and without relays is considered, and the condition for identical relay locations for both forward link and backlink data flow is derived. The results obtained can be used to evaluate tradeoffs among the different options for reducing vulnerability to external interference. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Error Recovery Technique for a Satellite Channel Assignment System with Distributed Control

    Publication Year: 1980 , Page(s): 1766 - 1771
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    A distributed control system for a set of earth stations sharing satellite communication channels is studied. The stations communicate by messages which may be corrupted by errors. A sufficient set of message types are defined to allow stations to enter and leave the system, to arbitrate for communication channels, and to recover from error situations. The errorprocesses assumed are of a transient nature, mainly existing on the interstation control channels. The signaling communication protocols are informally described in a Pascal-like language. The protocols are simulated in Simula and are found to work correctly in all cases studied. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A New Wide-Band System Architecture for Mobile High Frequency Communication Networks

    Publication Year: 1980 , Page(s): 1580 - 1590
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1240 KB)  

    A new wide-band HF communication system architecture for a multiple, mobile terminal network has been proposed and analyzed. This architecture embodies the complete removal of high power switching and tuning and achieves control of unwanted radiation by the use of highly linear power amplifiers and adaptive interference cancellation methods. To provide maximum flexibility in system operation, provision is made for transmitting and receiving subsystem assets to be shared among users to the greatest degree possible. The transmitter is simply a power bank into which all exciters are connected, and each receiver has access to a selection of antennas through power dividers, diversity combiners, and adaptive array processors. The implementation of this architecture will permit rapid and flexibile frequency selection and channel configuration to accommodate the complex network relaying strategy that will be necessary in modern warfare environment. Research is being conducted by the U.S. Navy on the technologies that require advancement if this architecture is to be brought to fruition for intratask-force communication. A system engineering analysis, substantial measurements and simulations of adaptive cancellation system performance, and development of critical system components have been conducted to validate the architectural concept. View full abstract»

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

    Publication Year: 1980 , Page(s): 1573 - 1579
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (976 KB)  

    The history of communications in the Navy has shown the importance of the role it plays in conducting military operations. A general overview of Navy communications is discussed, providing the framework for the new developments for the 1980's. Discussion focuses on three major areas: strategic, long-haul two-way, and tactical communications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Integrated Voice/Data Packet Switching Techniques for Future Military Networks

    Publication Year: 1980 , Page(s): 1655 - 1662
    Cited by:  Papers (5)  |  Patents (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    Virtual circuit and pure packet (datagram) based switching techniques are studied for future application to the integrated voice/data telecommunications. The coexistence of voice with both interactive and bulk data in an integrated network suggests the desirability of a mixed switching technique to allow the efficient sharing of both the switching and communications resources. Such a mixed packet switching scheme is also evaluated. It uses virtual circuit for regular traffic (voice and bulk data), and uses pure packet (datagram) for bursty traffic (interactive and query/response). It also adapts to changes in voice/ data input traffic mixture. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Conceptual Approaches to Switching in Future Military Networks

    Publication Year: 1980 , Page(s): 1491 - 1498
    Cited by:  Papers (2)  |  Patents (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (952 KB)  

    This paper presents conceptual approaches to the synthesis of switching functions in future military networks. The special requirements of military communications are shown to favor the implementation of integrated networks which provide all services (voice, data, imagery) within a single unified network structure. Transparent and transactional methods are defined as contrasting approaches to the realization of the required switching functions. The conceptual approaches to switching in future military networks are presented in the context of cultural differences which appear to exist between the differing perceptions of the adherents of circuit switching and packet switching. Special consideration is devoted to the issue of software engineering and the impact of current trends in DoD procurement policy. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance Analysis of a Majority Logic Multiplex System

    Publication Year: 1980 , Page(s): 1675 - 1680
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (584 KB)  

    The code division multiplexing (CDM) of digitally modulated baseband signals is normally referred to as majority logic multiplexing (MLM). The employment of MLM techniques in spread spectrum multiple access (SSMA) systems is especially attractive because it allows many different types of baseband channels to be easily combined. The traffic level can be gradually reduced to obtain a desired increase in processing gain, without affecting the active channels' share of the transmitter power. The code integrity and the processing gain of the SSMA equipment can be preserved by suitable design. This paper contains a general performance analysis of an MLM system that uses random codes. The basic MLM principle is extended to handle the combining of traffic channels with different bit rates. Calculated values of performance deterioration due to noise are compared with experimental results and found to be m close agreement. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Two-Level Coarse Code Acquisition Scheme for Spread Spectrum Radio

    Publication Year: 1980 , Page(s): 1734 - 1742
    Cited by:  Papers (27)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (808 KB)  

    A scheme for coarse acquisition of spread spectrum signals is described. It is characterized by a two-level acquisition process employing a passive correlator in tandem with a bank of active correlators. A threshold exceedance of the passive correlator initiates an interval of active correlation if any of the active correlators is idle. The scheme combines the rapid search capability of passive correlation with the decision reliability of (long) active correlation. An analytical model based on queuing and detection theory results is developed, and optimization of the scheme is treated. Performance in the presence of background noise with noise jamming and/or CW jamming is analyzed. Theoretical performance curves and a discussion of results are presented for each type of jamming. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • DSCS III--Becoming an Operational System

    Publication Year: 1980 , Page(s): 1499 - 1504
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    This paper addresses the progress of the Defense Satellite Communications System, Phase III (DSCS III), related developmental efforts directed toward facilitating operational employment of the new generation spacecraft, and an overview is provided illustrating how some of the innovations of the DSCS III will be used in the operational environment. The major features of the DSCS III are reviewed and a status report is provided on the development of the spacecraft. Special emphasis is given to those areas judged to be significantly different from other satellite systems-dynamic control of the multibeam antenna (MBA) systems, and its ability to detect and reduce the impact of interfering signals. Support software to expedite and optimize responses to changing operational requirements, including jamming, is addressed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Voice Communication in Integrated Digital Voice and Data Networks

    Publication Year: 1980 , Page(s): 1478 - 1490
    Cited by:  Papers (22)  |  Patents (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1400 KB)  

    Voice communication networks have traditionally been designed to provide either analog signal paths or fixed-rate synchronous digital connections between individual subscribers. These designs were aimed at accommodating the "streamlike" character of speech, which has traditionally been considered to flow from source to destination at a more or less constant rate. By way of contrast, interactive and computer-to-computer data transactions tend to be "bursty" in nature, and this has given rise to the development of packet-switching methods for data communications. The dichotomous nature of these two major traffic classes and the apparent conflict between the types of network services they require has resulted in the deployment of separate military communications facilities for voice and data. A challenge in the design of future systems is to achieve overall economy and flexibility in the allocation of resources via the efficient integration of both traffic types in common network facilities. This paper summarizes a number of advanced concepts for switching and flow control of combined voice and data traffic in integrated environments. Performance characteristics are described based on analysis results and computer simulation studies for both multilink terrestrial and broadcast satellite network topologies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Future Air Force Tactical Communications

    Publication Year: 1980 , Page(s): 1551 - 1572
    Cited by:  Papers (10)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2600 KB)  

    During the 1980's, many improvements will be made in the Air Force's ability to communicate in a battlefield environment. Programs like JTIDS, SEEK TALK, TRI-TAC, and the Ground Mobile Forces satellite communications terminals will improve the security, jam resistance, connectivity, and capacity of today's Air Force tactical communications. Even after these programs have been implemented, however, some important problem areas will remain, especially in our ability to resist a determined enemy's electronic warfare and physical attacks. This paper first describes today's Air Force tactical communications requirements and capabilities, and then summarizes the current problem areas. Currently planned programs to solve these problems are described for aircraft voice, aircraft data, ground-to-ground interconnections, and sensor/weapon data links. The problem areas that will remain after the implementation of these programs are then discussed. Some important technological opportunities are identified that hold promise for overcoming some of the projected problem areas in the 1990's. In addition, some system approaches are suggested for exploiting these technological opportunities, and for improving our use of older technologies. These system approaches emphasize reduced-information-rate operation, adaptive network techniques, network management/control, packet switching, and joint-Service, interoperable, common-user systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of Tactical Communications Jamming Problems

    Publication Year: 1980 , Page(s): 1625 - 1630
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB)  

    This paper reviews the technical disciplines needed to analyze technical communications jamming problems. Such problems rarely involve pure free-space propagation so that careful attention is needed to propagation characteristics. The various sources that contribute uncertainty to the problem are enumerated and estimates are given of their magnitude. View full abstract»

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

Aims & Scope

IEEE Transactions on Communications focuses on all telecommunications including telephone, telegraphy, facsimile, and point-to-point television by electromagnetic propagation.

 

 

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Robert Schober
University of British Columbia