574 research outputs found

    Allocation of Orbit and Spectrum Resources for Regional Communications: What's at Stake?

    Get PDF
    Contentious debate surrounds allocation of the geostationary orbit and electromagnetic spectrum, two resources used by communications satellites. An extensive economics literature alleges that the nonmarket administrative allocative procedures now in place are highly inefficient, but no research has empirically estimated the welfare loss. This paper develops a conceptual framework and a computerized model to estimate the economic value of the resources, the size and distribution of welfare costs associated with the present regulatory regime, and the potential gains from more market-like allocation.

    Communications satellite systems capacity analysis

    Get PDF
    Analog and digital modulation techniques are compared with regard to efficient use of the geostationary orbit by communications satellites. Included is the definition of the baseline systems (both space and ground segments), determination of interference susceptibility, calculation of orbit spacing, and evaluation of relative costs. It is assumed that voice or TV is communicated at 14/11 GHz using either FM or QPSK modulation. Both the Fixed-Satellite Service and the Broadcasting-Satellite Service are considered. For most of the cases examined the digital approach requires a satellite spacing less than or equal to that required by the analog approach

    Numerical arc segmentation algorithm for a radio conference-NASARC (version 2.0) technical manual

    Get PDF
    The information contained in the NASARC (Version 2.0) Technical Manual (NASA TM-100160) and NASARC (Version 2.0) User's Manual (NASA TM-100161) relates to the state of NASARC software development through October 16, 1987. The Technical Manual describes the Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) concept and the algorithms used to implement the concept. The User's Manual provides information on computer system considerations, installation instructions, description of input files, and program operating instructions. Significant revisions have been incorporated in the Version 2.0 software. These revisions have enhanced the modeling capabilities of the NASARC procedure while greatly reducing the computer run time and memory requirements. Array dimensions within the software have been structured to fit within the currently available 6-megabyte memory capacity of the International Frequency Registration Board (IFRB) computer facility. A piecewise approach to predetermined arc generation in NASARC (Version 2.0) allows worldwide scenarios to be accommodated within these memory constraints while at the same time effecting an overall reduction in computer run time

    Useful applications of earth-oriented satellites - Point-to-point communications

    Get PDF
    Existing and future developments for worldwide commercial or common carrier point to point communication satellite system

    NASA and the challenge of ISDN: The role of satellites in an ISDN world

    Get PDF
    To understand what role satellites may play in Integrated Services Digital Network (ISDN), it is necessary to understand the concept of ISDN, including key organizations involved, the current status of key standards recommendations, and domestic and international progress implementation of ISDN. Each of these areas are explained. A summary of the technical performance criteria for ISDN, current standards for satellites in ISDN, key players in the ISDN environment, and what steps can be taken to encourage application of satellites in ISDN are also covered

    Orbit-spectrum sharing between the fixed-satellite and broadcasting-satellite services with applications to 12 GHz domestic systems

    Get PDF
    A systematic, tutorial analysis of the general problem of orbit-spectrum sharing among inhomogeneous satellite system is presented. Emphasis is placed on extrapolating and applying the available data on rain attenuation and on reconciling differences in the results of various measurements of the subjective effects of interference on television picture quality. An analytic method is presented for determining the approximate values of the intersatellite spacings required to keep mutual interference levels within prescribed limits when many dissimilar satellites share the orbit. A computer model was developed for assessing the interference compatibility of arbitrary configurations of large numbers of geostationary satellite systems. It is concluded that the band from 11.7 c GHz can be shared effectively by broadcasting-satellite and fixed-satellite systems. Recommendations for future study are included

    Communication satellite systems for Alaska

    Get PDF
    Technical and cost factors for implementation of Alaskan communication satellite syste

    Geostationary platform systems concepts definition study. Volume 2: Technical, book 2

    Get PDF
    A selected concept for a geostationary platform is defined in sufficient detail to identify requirements for supporting research and technology, space demonstrations, GFE interfaces, costs, and schedules. This system consists of six platforms in geostationary orbit (GEO) over the Western Hemisphere and six over the Atlantic, to satisfy the total payload set associated with the nominal traffic model. Each platform is delivered to low Earth orbit (LEO) in a single shuttle flight, already mated to its LEO to GEO transfer vehicle and ready for deployment and transfer to GEO. An alternative concept is looked at briefly for comparison of configuration and technology requirements. This alternative consists of two large platforms, one over the Western Hemisphere consisting of three docked modules, and one over the Atlantic (two docked modules), to satisfy a high traffic model. The modules are full length orbiter cargo bay payloads, mated at LEO to orbital transfer vehicles (OTVs) delivered in other shuttle flights, for transfer to GEO, rendezvous, and docking. A preliminary feasibility study of an experimental platform is also performed to demonstrate communications and platform technologies required for the operational platforms of the 1990s

    Numerical Arc Segmentation Algorithm for a Radio Conference-NASARC (version 4.0) technical manual

    Get PDF
    The information contained in the NASARC (Version 4.0) Technical Manual and NASARC (Version 4.0) User's Manual relates to the Numerical Arc Segmentation Algorithm for a Radio Conference (NASARC) software development through November 1, 1988. The Technical Manual describes the NASARC concept and the algorithms used to implement the concept. The User's Manual provides information on computer system considerations, installation instructions, description of input files, and program operation instructions. Significant revisions were incorporated in the Version 4.0 software over prior versions. These revisions have further enhanced the modeling capabilities of the NASARC procedure and provide improved arrangements of predetermined arcs within the geostationary orbits. Array dimensions within the software were structured to fit within the currently available 12 megabyte memory capacity of the International Frequency Registration Board (IFRB) computer facility. A piecewise approach to predetermined arc generation in NASARC (Version 4.0) allows worldwide planning problem scenarios to be accommodated within computer run time and memory constraints with enhanced likelihood and ease of solution

    The Right Stuff in Geospace: Using Mutual Coercion to Avoid an Inevitable Prison for Humanity

    Get PDF
    Even though you cannot see it, catastrophe is brewing in near-Earth orbit. As a product of the Cold War, the legal regime governing geospace and beyond has presented mankind with a paradox. Though we are free to utilize space through peaceful means, the inability to appropriate space by any sovereign claim of right has triggered a modern-day tragedy of the commons, with the only restriction being the constraints of radio frequency interference. The destructive domino effect of space debris collisions threatens the invaluable communicative and scientific utility derived from satellites in geospace. International and domestic space jurisprudence encourage space debris mitigation, but without binding provisions, spacefarers will continue to favor economic incentives over conservation. Any workable reimagining of the Corpus Juris Spatialis requires balancing the equities between capital investors and beneficiaries on Earth. Proposals for market share liability regimes, salvage law amendments, and environmental protocols can fill in existing gaps. Yet each of these solutions places inequitable burdens on those with a pre-existing presence in space. Using Garrett Hardin’s solutions to alleviate the negative utility of space activity, a coercive protocol to the Outer Space Treaty can moderate behavior while still permitting satellite acquisitions and exploration of the cosmos. By following the historical trend of airspace delimitation, jurists must first define the boundaries of geospace. Thereafter, applying a separate legal regime with a mutually coercive global liability provision in the geospace commons can save us from an otherwise inevitable prison for humanity
    • …
    corecore