International Journal of Satellite Communications and Networking

Cover image for Vol. 30 Issue 4

July/August 2012

Volume 30, Issue 4

Pages 147–191

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. On the interference from space research service uplink transmissions into the inter-satellite links of a non-GSO system operating in the 22-GHz band (pages 147–162)

      José Mauro P. Fortes and Juan Otalora Goicochea

      Version of Record online: 7 MAR 2012 | DOI: 10.1002/sat.1009

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      This paper presents a compatibility analysis involving space research service lunar mission uplink transmissions and the inter-satellite links of non-GSO systems operating in the 22-GHz band. Besides the usual unconditional interference cumulative distribution functions, the analysis also considers the conditional cumulative distribution functions given that the victim satellite is receiving interference, which are important to characterize the interference affecting users that, owing to their location, are most of the time using satellites, which are under interference.

    2. On the quality of VoIP with DCCP for satellite communications (pages 163–180)

      Golam Sarwar, Roksana Boreli and Emmanuel Lochin

      Version of Record online: 10 MAY 2012 | DOI: 10.1002/sat.1010

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      We present experimental results for the performance of selected voice codecs using DCCP with CCID4 congestion control over a satellite link. We evaluate the performance of both constant and variable data rate speech codecs using the ITU E-model. We identify the additional benefit of DCCP when used in VoIP admission control mechanisms and draw conclusions about the advantages and disadvantages of the proposed DCCP/CCID4 congestion control mechanism for use with VoIP applications.

    3. GPS spoofer countermeasure effectiveness based on signal strength, noise power, and C/N0 measurements (pages 181–191)

      Ali Jafarnia Jahromi, Ali Broumandan, John Nielsen and Gérard Lachapelle

      Version of Record online: 18 JUN 2012 | DOI: 10.1002/sat.1012

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      Spoofing signals can effectively mislead the GNSS receivers into generating false position and navigation solution. This paper analyses the effectiveness of C/N0 monitoring versus absolute power monitoring in the context of GPS spoofing countermeasure. As shown, whereas the C/N0 based spoofing discrimination is of limited effectiveness, with a modest circuit modification, the GPS receiver can measure the absolute power of the received signals, which is an effective means of detecting spoofer sources.