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NASA Man-Made Noise Floor Study Summary Program Results

NASA Man-Made Noise Floor Study Summary Program Results. National Spectrum Managers Association May 25, 2005 James E. Hollansworth NASA Headquarters. Measurements of Man Made Spectrum Noise Floor. Rationale & Objective:

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NASA Man-Made Noise Floor Study Summary Program Results

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  1. NASA Man-Made Noise Floor StudySummary Program Results National Spectrum Managers Association May 25, 2005 James E. Hollansworth NASA Headquarters

  2. Measurements of Man Made Spectrum Noise Floor • Rationale & Objective: • In many instances new wireless technologies support applications in unlicensed bands or “underlay” existing services on an unlicensed basis. • This could result in a degradation of the noise-floor environment. • There is a need to examine whether the observed noise floor results are consistent with applicable regulations governing those bands • NASA is particularly concerned with noise floor in bands used for crucial safety and scientific purposes • NASA Partnership with the Department of Transportation, Clemson University, & Stanford University • Funding by NASA and DOT • Published as NASA CR-2004-213551, available at http://ntrs.nasa.gov/

  3. Stanford University conducted a survey in the L1-Band (1563.42 - 1587.42 MHz), Unified S-Band (2025-2110 MHz), and Industrial Scientific and Medical Band (2400 - 2482.5 MHz) Clemson University conducted a survey in the Passive Sensing Band (23.6 – 24.0 GHz) L1 - Band S - Band 2.4 ISM -Band Passive Sensor Band Measurements of Man Made Spectrum Noise Floor

  4. Measurements of Man Made Spectrum Noise Sample Survey: San Jose Downtown, CA GPS L1 Band Measurements Equipment and Location GPS L1-Band Temporal, Spectral, Angular, & Statistical Analysis

  5. Key Significantly greater than natural noise power Slightly above the natural noise power Indistinguishable from the natural noise power Stanford Measurement Results • Stanford University Survey Results • The GPS L1 Band is relatively pristine and quiet • The Unified S Band has emissions due to non-Government services • The 2.4 GHz ISM Band is discernibly noisier than regulated bands • Urban areas are noisier than rural environments • Airports and harbors are generally similar to urban areas Average Received Power (in dBm/MHz)

  6. Clemson Measurement Results • Clemson University Survey Results at 24 GHz • Overall no appreciable levels of man-made radiation • Nineteen spectral peaks were, however, detected at two airport sites • 3 in a single frequency at Hartsfield Jackson Airport • 10 at the Oconee County Airport • Anomalies possibly related to satellite service to commercial trucks

  7. Conclusions • In bands open to public utilization, the power spectrum is far above the thermal noise floor • In restricted bands the power spectrum is close to the thermal noise floor • Current rules appear to be effective in determining the radio environment • Future regulations should be sensitive to the function of each band: • Each band supports different types of applications • Some bands support critical systems and cannot tolerate operational failure and need to be protected from any interference • Other bands can tolerate a certain level of interference while requiring more bandwidth • Restricted bands should not be considered for operations of unlicensed and unregulated services

  8. For additional information contact: James E. Hollansworth (Jim) NASA Headquarters (202) 358-4675 jhollans@hq.nasa.gov

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