ATNGNSS Seminar Varadero, Cuba 6 to 9 May 2002

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ATN/GNSS SeminarVaradero, Cuba6 to 9 May 2002

• GNSS spectrum and signal vulnerability issues
• Presentation 5.2 by
• V. Iatsouk, GNSS Panel Secretary
• ANB/ICAO

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GNSS spectrum allocations

• Current allocations
• New allocations to support system
  enhancements and expansion
• Compatibility issues

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FREQUENCY BAND 1559 1610 MHz (ARNS/RNSS)

• GNSS F1 signals (GPS L1, GLONASS L1, GALILEO
  E1/2)
• Total band 1559-1610 MHz is required for current
  and future GNSS
• Sharing with other services will cause
  unacceptable degradation and restrictions on GNSS
  elements
• Additional allocation to Fixed Service (some
  States in Europe, Middle East, Asia and Africa)
  continue to exist
• On a primary basis until 2005 (or 2010)
• On a secondary basis until 2015

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Frequency Band 960 1215 MHz (ARNS, RNSS)

• RNSS allocation as of WRC-2000
• GNSS F2 frequencies
• Sharing with DME on 1164 1215 MHz frequencies
• Compatibility issues
• DME to be protected
• GNSS F2 signals to operate in DME environment
• Out-of-band (Radiolocation above 1 215 MHz)
  interference

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Frequency band 1215 1300 MHz (Radiolocation,
RNSS)

• No aeronautical allocation
• GPS L2, GLONASS L2, GALILEO E6
• Used by SBAS reference receivers
• Compatibility issues
• Radiolocation to be protected
• No protection for RNSS on a global basis

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Frequency band 108 117.975 MHz (ARNS)

• GBAS VDL Broadcast
• Sharing with VOR and ILS
• Compatibility issues
• VOR, ILS to be protected
• VDL Broadcast
• To operate in VOR, ILS environment
• Not to impose additional restrictions in adjacent
  bands (FM Broadcast below 108 MHz, Aeronautical
  Mobile above 117.975 MHz)

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GNSS vulnerability aspects

• GNSS signals vulnerability is generally
  recognized
• Issues to be addressed
• Interference cases and resulting threats
• Operational impact
• Mitigations

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Interference cases

• Unintentional vs intentional
• In-band vs out-of-band
• On-board sources
• Natural phenomena

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Intentional interference

• Jamming
• Threat is valid
• Risks and impacts vary significantly
• Most mitigation options are suitable
• Spoofing
• Extent of threat appears to be low
• Airborne collision avoidance, situation awareness
  and separation assurance capabilities are
  potential mitigation aids
• Other mitigation options are also suitable

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Unintentional interference

• GNSS F1 signals in 1 559 1 610 MHz band
• Fixed service (not compatible)
• Mobile satellite communications (compatibility
  standards exist)
• GPS, GLONASS, GALILEO signals above 1 215 MHz
• RNSS/Radiolocation Service compatibility
  (studies under way)

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Unintentional interference (contd)

• GNSS GBAS in 108 117.975 MHz band
• VOR (compatibility criteria available)
• ILS (compatibility criteria being developed)
• Aeronautical VHF Communications (compatibility
  criteria being developed)
• FM broadcast (compatibility criteria available)
• Envisaged VDL Mode 4, if allocated by
  WRC-2003 (compatibility studies under way)

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Unintentional interference (contd)

• GNSS F2 signals in 1 164 1 215 MHz band
• Designed to be compatible with ARNS
• Compatibility problems in DME high density areas
  (core Europe, US, Japan)
• On-board compatibility
• Compatibility standards exist
• Addressed through aircraft systems integration

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Natural interference sources

• Ionospheric effects
• Storms
• Model anomalities
• Scintillations impacts
• Other (heavy rainfalls?)

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Operational Impacts

• Effects of interference to be assessed taking
  account of
• Traffic density
• Navigation infrastructure
• Surveillance system

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Mitigations

• Spectrum management, coordination and
  interference monitoring
• Use of alternative navigation means
• Procedural methods
• Contingency planning

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Work towards WRC - 2003

• Promote cessation of fixed services in the
  1559-1610 MHz band as early as possible
• Finalize compatibility criteria and assessment
  methodology for RNSS in the 1164-1215 MHz band
• Formalize GBAS operation in 108 117.975 MHz
  band

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Conclusions

• Global coverage and performance to support all
  phases of flight are dependent upon resolution of
  spectrum issues
• States to ensure freedom of RF interference when
  approving GNSS operations
• Interference threats to be assessed and
  mitigation strategy to be developed as a part of
  GNSS implementation planning

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(No Transcript)