832 research outputs found

    On-board congestion control for satellite packet switching networks

    Get PDF
    It is desirable to incorporate packet switching capability on-board for future communication satellites. Because of the statistical nature of packet communication, incoming traffic fluctuates and may cause congestion. Thus, it is necessary to incorporate a congestion control mechanism as part of the on-board processing to smooth and regulate the bursty traffic. Although there are extensive studies on congestion control for both baseband and broadband terrestrial networks, these schemes are not feasible for space based switching networks because of the unique characteristics of satellite link. Here, we propose a new congestion control method for on-board satellite packet switching. This scheme takes into consideration the long propagation delay in satellite link and takes advantage of the the satellite's broadcasting capability. It divides the control between the ground terminals and satellite, but distributes the primary responsibility to ground terminals and only requires minimal hardware resource on-board satellite

    Forecasting international bandwidth capacity using linear and ANN methods

    Get PDF
    An artificial neural network (ANN) can improve forecasts through pattern recognition of historical data. This article evaluates the reliability of ANN methods, as opposed to simple extrapolation techniques, to forecast Internet bandwidth index data that is bursty in nature. A simple feedforward ANN model is selected as a nonlinear alternative, as it is flexible enough to model complex linear or nonlinear relationships without any prior assumptions about the data generating process. These data are virtually white noise and provides a challenge to forecasters. Using standard forecast error statistics, the ANN and the simple exponential smoothing model provide modestly better forecasts than other extrapolation methodsForecasting; international bandwidth capacity

    ISDN at NASA Lewis Research Center

    Get PDF
    An expository investigation of the potential impact of the Integrated Services Digital Network (ISDN) at NASA Lewis Research Center is described. To properly frame the subject, the paper contains a detailed survey of the components of Narrowband ISDN. The principles and objectives are presented as decreed by the Consultative Committee for International Telephone and Telegraph (CCITT). The various channel types are delineated and their associated service combinations are described. The subscriber-access network functions are explained pictorially via the ISDN reference configuration. A section on switching techniques is presented to enable the reader to understand the emergence of the concept of fast packet switching. This new technology is designed to operate over the high bandwidth, low error rate transmission media that characterizes the LeRC environment. A brief introduction to the next generation of networks is covered with sections on Broadband ISDM (B-ISDN), Asynchronous Transfer Mode (ATM), and Synchronous Optical Networks (SONET). Applications at LeRC are presented, first in terms of targets of opportunity, then in light of compatibility constraints. In-place pilot projects and testing are described that demonstrate actual usage at LeRC

    Architecture, design, and modeling of the OPSnet asynchronous optical packet switching node

    Get PDF
    An all-optical packet-switched network supporting multiple services represents a long-term goal for network operators and service providers alike. The EPSRC-funded OPSnet project partnership addresses this issue from device through to network architecture perspectives with the key objective of the design, development, and demonstration of a fully operational asynchronous optical packet switch (OPS) suitable for 100 Gb/s dense-wavelength-division multiplexing (DWDM) operation. The OPS is built around a novel buffer and control architecture that has been shown to be highly flexible and to offer the promise of fair and consistent packet delivery at high load conditions with full support for quality of service (QoS) based on differentiated services over generalized multiprotocol label switching

    TV-Centric technologies to provide remote areas with two-way satellite broadband access

    Get PDF
    October 1-2, 2007, Rome, Italy TV-Centric Technologies To Provide Remote Areas With Two-Way Satellite Broadband Acces
    • 

    corecore