1. Aircraft 60 GHz BRAN 20-22 April 2016 Prepared by Steven H. Rines,
Staff Systems Engineer
20-22 April 2016

2. 60 GHz BRAN in Aircraft Cabins
60 GHz BRAN can be used in aircraft cabins without interfering with existing scientific or environmental endeavors.
Concerns
Radio Astronomy interference
Weather radar (EESS) interference
Approach
RAS interference study
Aircraft fuselage attenuation study and verification testing
Aircraft cabin to be defined as an indoor environment based on fuselage attenuation
Limiting of frequency range considered
Remaining Issues
International Regulation/Operation

3. Regulatory Standards for RAS

4. ITU-R REC M.2238 Attenuation

5. Project Status
Link budget modeling for radio astronomy is complete based on ITU Methodology for Interference calculation
Channels 2 and 3 have dB interference margin using fuselage attenuation values given in ITU-R REC M.2238.
Aircraft measurement campaign planned with Airbus and Technische Universität Braunschweig to verify fuselage attenuation values from ITU-R REC M.2238 apply at 60 GHz
Cabin BRAN coverage analysis and verification complete.
Stated attenuation for aircraft window was biggest concern. Theoretical modeling of windows is now complete.
A study by the Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut state windows are metallized and have a permittivity of 2.25.* This has yet to be confirmed.
Attenuation model verification will be done with actual window hardware. *

6. Slant Range Attenuation
Atmospheric attenuation in dB
Frequency in GHz
Atmospheric Slant Path Attenuation (terrestrial receive antenna altitude 2.2 km, aircraft altitude 13.7 km)

7. Aircraft Window Assembly
Typical Aircraft Window Assembly
B787

8. Transmit Source Perpendicular to Window
Assumptions:
Single source tx at normal incidence
ηair = 1.0
ηacrylic =
One reflection accounted for at each dielectric interface
No reflective film or coatings on any of the surfaces

9. Transmit Source at Oblique Angle Window
15.6 dB attenuation due to reflective loss at 79 degree critical angle.
100% internal reflection at angles greater than 79 degrees.
Assumptions:
Single source tx at TIR derived corner case oblique incidence
nair = 1.0
nacrylic =
One reflection accounted for at each dielectric interface
No reflective film or coatings on any of the surfaces

10. Aircraft Window Attenuation
ITU-R REC M.2238 attenuation values did not account for attenuation due to reflection.
Window Power Loss = Reflective Loss + Material Absorption Loss
Power Loss at Normal Incidence:
1.4 dB + (1.695cm)x(6.03dB/cm) = dB
Power Loss at Maximum Oblique Incidence:
15.6 dB + (1.695cm)x(6.03dB/cm) = dB
Power losses above should be taken as worst case as calculations do not take coatings or metallization into account.

11. IFE Seat Transmitter Positioning (vertical)
Entertainment display height typically aligns with window height.

12. Example Beam Steering Antenna Pattern
Example 30 degree main lobe with 20 dB attenuation in Horizontal and vertical sidelobes and 38 dB attenuation beyond 100 degrees from target.

13. Additional Windows Attenuation Details
Windows fore and aft of current seat row are typically blocked from a seat display by other seat backs.
Signal from seat back transmitters presented to window will not be primary lobe.
Any signal from access point presented to window will always be an oblique angle.
Half duplex nature of WiGig limits the number of simultaneous transmitters to the number of access points on the aircraft.
If necessary, available RF film technologies can be applied to windows to add an additional 10 dB attenuation.

14. WRC-2000 Footnote 5.558
In the bands GHz, GHz, GHz, GHz, GHz, GHz and GHz, stations in the aeronautical mobile service may be operated subject to not causing harmful interference to the inter-satellite service (see No. 5.43).

15. Directive 1999/5/EC [2] (R&TTE Directive), article 3.2
"….. radio equipment shall be so constructed that it effectively uses the spectrum allocated to terrestrial/space radio communications and orbital resources so as to avoid harmful interference“
In the case of aeronautical BRAN, radio astronomy and weather satellite are the systems which we must avoid interference with.

16. CEPT ERC 70-03
"The CEPT has considered the use of SRD devices on board aircraft and it has concluded that, from the CEPT regulatory perspective, such use is allowed under the same conditions provided in the relevant Annex of Recommendation For aviation safety aspects, the CEPT is not the right body to address this matter which remains the responsibility of aircraft manufacturers or aircraft owners who should consult with the relevant national or regional aviation bodies before the installation and use of such devices on board aircraft.“
CEPT ERC has no specific prohibitions for use on aircraft from GHz
However,
32 EU countries prohibit aeronautical mobile from GHz
27 EU countries prohibit aeronautical mobile from GHz

17. International Regulatory status
Numerous aeronautical restrictions outside EU including USA
FCC NPRM A1 proposes expansion of 60 GHz band from to GHz and removal of aeronautical prohibition

18. Boeing response to FCC NPRM
“… Boeing also supports expanding the spectrum that is available for Part 15 unlicensed operations. Permitting Part 15 operations in the GHz band by non-federal users will provide more opportunities for the development and marketing of industrial and consumer equipment that utilize unlicensed wireless communications for function and user control.
Likewise, authorizing Part 15 operations in the GHz band on board aircraft can benefit airline passengers and aircraft operators while continuing to protect radio astronomy services.”

19. Airbus response to FCC NPRM
“As a leading company that designs and manufactures transport airplanes in facilities worldwide including the United States, Airbus sees much interest in the use of equipment of the next WiFi generation (WiGig), in industrial facilities as well as on board aircraft. The extension of the unlicensed band and the possibility to use it on board aircraft would respond to a real increasing need and can be achieved in safe conditions. Airbus has carefully read the comments and reply comments regarding the possible extension of unlicensed operations in higher frequency bands. In particular, Airbus concurs with the analysis and conclusions provided in The Boeing Company's comments dated January 28, 2016 (section II A & B) and reply comments dated February 26, 2016 (section V A & B). In conclusion, Airbus supports the extension of unlicensed operations to the GHz band and the lift of the ban on unlicensed operations in the GHz band on board aircraft.”

20. CORF Latest Response to FCC NPRM
Comments Filed Supporting Unlicensed Airborne Use of 60 GHz Devices Did Not Address the Negative Impact on Critical EESS Observations.
In CORF’s opening comments (hereafter, “CORF’s opening comments”) in this proceeding (at pages 11-16), in light of the Commission’s proposal to unify rules in the GHz band with those for operations at GHz, CORF noted that the GHz sub-band is vitally important for weather forecasting from satellite remote sensing instruments, which cannot be moved to another frequency. CORF strongly urges the Commission to use great caution before authorizing aeronautical transmissions at GHz and recommends further study of real-world transmission scenarios in aircraft prior to authorizing unlicensed airborne use of this band.
… the Commission should consider (1) making any service at GHz licensed and requiring aircraft operator licensees to retain responsibility for ensuring that RF leakage levels are below required threshold levels (for the aggregate transmissions from the aircraft) if aeronautical operations are permitted or (2) in the absence of better data, prohibiting airborne use of WiGig Channel 1 ( GHz).

21. Need to Limit Spectrum Use on Aircraft?
The goal is to establish a common frequency band that is usable internationally and will not interfere with scientific or environmental activities.
CORF/NAS strongly recommends prohibiting BRAN use on aircraft from GHz due to potential EESS interference.
Further, CORF/NAS voiced concerns of harmonics of GHz use affecting radio astronomy
Many countries still prohibit aeronautical mobile from GHz.
Modeling and analysis indicates that GHz will meet interference margins.

22. International Standards for Airborne BRAN
Where should aeronautical BRAN system constraints reside to ensure international adoption?
How will aeronautical BRAN installers be monitored to ensure systems will comply for non-interference with EESS and radio astronomy?
Aviation Maintenance Repair Organizations (MROs) must submit system certification documentation that includes safety assessment, design criteria and system test results to demonstrate non-interference with other aircraft systems.
Is an SRDoc required to capture the constraints for international aviation telecommunications installations?

23. ETSI TR 102 555 v 1.1.1 7 Requested ECC actions
It is proposed that ECC considers the proposed regulation in clause 6 and identifies the final frequency tuning band for
59 GHz to 66 GHz license-exempt operation. It is proposed that National Authorities implement the full MHz
frequency designation
Changes required to TR to enable aeronautical use

24. EN v1.2.1
No specific aeronautical usage constraints
40 dBm Maximum power level indoor and outdoor
-30 dB Maximum transmit spurious
-47 dB Maximum Receiver spurious emissions

25. How can aircraft systems be introduced considering the international regulatory environment?
Every wide body aircraft installation will potentially operate across one or more country borders
CEPT Short Range Device concept works well for devices carried from one country to another and operated within regulatory constraints in each country.
CEPT Short Range Device concept works on aircraft installations using radio certification in aircraft country of registration and using visitor device status for countries being overflown.
CEPT Short Range Device concept does not address airborne operation over countries that do not have harmonized regulations in place.
Aircraft BRAN design and installation is extremely expensive and can only be undertaken by airlines once the international regulatory situation has been clearly established.

26. Thank you for your attention
Please direct any questions or comments to:
Zodiac Inflight Innovations
2929 E. Imperial Hwy
Brea, CA USA
Steven H. Rines
Staff Systems Engineer
Ph: