Response to Request for Further Information

1076-EX-ST-2018 Text Documents

O3b Limited

2018-08-13ELS_214056

August 10, 2018 VIA ELECTRONIC FILING Anthony Serafini Experimental Licensing Branch Chief, Office of Engineering and Technology Federal Communications Commission 445 12th Street, SW Washington, D.C. 20554 Re: Request for Further Information; Call Sign WN9XBH; File No. SAT- 1076-EX-ST-2018 Dear Mr. Serafini: O3b Limited (“O3b”) files this letter in response to a request for further information regarding its pending application for special temporary authority to conduct tests of a new GetSat MicroSat terminal at the SES facility in Manassas, VA. SES has provided its answers to the Commission’s inquiries below: 1) Please submit a radiation hazard for the proposed antennas Please see attached Annex A for a radiation hazard report for the proposed antenna. 2) Please demonstrate that your proposed operations in the 27.5-30 GHz will meet the equivalent power Flux-density (epfd) levels in the Table 22-2 of Article 22, Section II, and Resolution 76 of the ITU Radio Regulations. Please see Annex B for a demonstration that the proposed operations will meet the EPFD levels in Table 22-2 of Article 22, Section II, and Resolution 76 of the ITU Radio Regulations. 3) Please certify that your proposed operations are in compliance with all existing or future coordination agreements between O3b and other GSO and NGSO satellite networks, or demonstrate that your proposed operations will not cause interference to terrestrial, iridium NGSO, and GSO satellite networks. O3b certifies that its proposed operations will comply with all existing or future coordination agreements between O3b and other satellite operators and will abide by all the 1/2 SES société anonyme Tel. +352 710 725 1 Company Register No. B 81 267 Château de Betzdorf Fax +352 710 725 227 Identification No. LU18953352 L-6815 Betzdorf Enter sender e-mail Luxembourg www.ses.com

terms and conditions of the O3b Market Access Grant.1 In addition, as stated in its application, O3b will coordinate with local terrestrial operators prior to transmitting in any bands that are shared with terrestrial services. Respectfully submitted, SES Networks /s/ Will Lewis Will Lewis Senior Legal Counsel 900 17th Street NW Suite 300 Washington D.C. 20006 (202) 813-4033 cc: Paul Blais Attachment 1O3b Limited, Order and Declaratory Ruling, Call Sign S2935, FCC 18-70 at ¶ 20 (rel. June 6, 2018). 2/2 SES société anonyme Tel. +352 710 725 1 Company Register No. B 81 267 Château de Betzdorf Fax +352 710 725 227 Identification No. LU18953352 L-6815 Betzdorf Enter sender e-mail Luxembourg www.ses.com

Annex A – Radiation Hazard Report

Radiation Hazard Analysis 0.24 Meter - Manassas, Virginia 20136 Introduction A radiation hazard anaylsis is presented for a 0.24 meter Ka band aperture antenna to be installed in Manassas, Virginia at the SES Networks SES Facility. This Radiation Analysis calculates the non-ionizing radiation levels expected to be emitted from the earth station on a worse cases basis and is performed in accordance with the Federal Communications Commissions Office of Engineering and Technology (OET) Bulletin, No. 65. Requirements OET 65 outlines the maximum permissible exposure limits in two cases for operation in this frequency range. 1. The first case is the maximum level that a person may be exposed to in the general population. The exposure limit is defined as a non-ionizing power level equal to 1 milliwatt per centimeter squared averaged over a thirty minute period. 2. The second case is a controlled environment where the maximum permissible exposure limit must not exceed 5 milliwatts per centimeter squared averaged over any six minute period. Summary The results indicate that no significant hazard will be presented to the general population and will be fully mitigated in the controlled area by the use of procedures that require the removal of transmit power before accessing the area around the main reflector. Analysis This analysis was performed on seven zones. The results of this is shown in Radiation Hazard Zones. The Table labeled Input Values provides the input data used to perform the analysis. The table labeled OET 65 Calculated Values provides the intermediate calculation used to perform the assessment in accordance with OET 65. The Analysis is performed for each of the seven radiation zones as shown in figure 1 – Analysis Zones. These zones are: 1. Point between the feed and the sub-reflector 2. The power at the surface of the antenna 3. The power level between the main reflector and ground 4. The near-field or Fresnel region in which the maxima can be reached before the field starts to diminish with distance 5. The Transition region where power begins to decrease inversely with distance from the antenna 6. The Far Field or Fraunhofer region where power decreases inversely with the square of the distance. This is the point at which the antenna beam is fully collimated 7. The off axis level in the near field. This is defined as the area outside of the main beam removed and at least one antenna diameter removed from the main beam 2. Main Reflector 1.Subreflector 4.Near Field 5. Transition 6. Far Field 3. Main Reflector Ground 7.Off Axis Near Field Figure 1 – Analysis Zones Generated 8/9/2018 Page 1 of 1 Rad Haz GetSat Final

Radiation Hazard Analysis Operator: SES Networks Location Designation: SES Facility FCC ID: County: Prince William SES ID: Town: Manassas, STA: State/Zip: Virginia 20136 Input Values Value Unit Band Frequency GHz D = Aperture Diameter 0.24 Meters L 1000-2000 d = Subreflector Diameter 0 Meters S 2000-4000 60% percentage C 4000-8000 FCC Designation Ka Band X 8000-12500 F = Frequency 29500 MHz Ku 12500-18000 P = Transmitter Power Watts: 25 Watts K 18000-25500 p = Number Transmitters: 1 Ka 26500-40000 R ua = closest point to uncontrolled area 10 meters O 40000-50000 Elevation angle at closest point R ua 20 Degrees V 50000-75000 OET 65 Calculated Values Formula Value Unit λ= Wavelength c/F 0.0102 meters P 1 = Total Antenna Input Power P*p 25 watts G = Antenna Gain 3294.84169 linear Antenna Gain dB 35.17834552 dBi A = Area of reflector 0.045216 meters 2 a = area of subreflector 0 meters 2 R nf = Near-Field Region 1.42 meters 1.416 >meters Transition Region 3.3984 <meters 3.3984 meters R ff = Far Field Region 1 Meters AGL Exposure Limits Radiation Analysis Zone Formula Level Value General Public Occupational 2 2 <1mW/cm <5mW/cm 1 Power Subreflector N/A mW/cm 2 N/A N/A 2 >FCC MPE See 2 Antenna Surface 221.161 mW/cm >FCC MPE See Note 2 Note 1 >FCC MPE See 3 Main Reflector Ground 55.290 mW/cm 2 Note 1 >FCC MPE See Note 2 >FCC MPE See 4 Snf =Near-Field Power Density 265.393 mW/cm 2 Note 1 >FCC MPE See Note 2 >FCC MPE See 5 Max Transition Power Density 265.393 mW/cm 2 Note 1 >FCC MPE See Note 2 >FCC MPE See 6 Max Far field Power Density 56.785 mW/cm 2 Note 3 >FCC MPE See Note 2 7 Off Access Level Near Field 2.65393 mW/cm 2 >FCC MPE See Note 1 <FCC MPE Notes 1. The antenna is installed in a controlled location access is restricted to authorized personnel only. The area is marked with RF Radiation Hazard signage. Area not accessible to the general public. 2. Inside the controlled area, MPE levels exceed the MPE exposure for occupational levels. The levels will be reduced to safe MPE by removing power to the transmitters when work is performed on or around the antenna. This area can only be accessed by qualified personnel. 3. The far field develops 1 meters above ground level at the minimum elevation angle which is not accessable to the general public. Generated 8/9/2018 Page 1 of 2 Rad Haz GetSat Final

Annex B – Demonstration of Compliance with EPFD Limits

The following plot illustrates the GETSAT antenna pattern in azimuth and elevation dimensions. The below analysis shows the GSO arc, as it appears from the location where the GETSAT antenna will be operating, is superimposed on to the antenna pattern. There are multiple instances of the GSO arc shown because the GETSAT antenna will be moving to follow O3b satellites. At each increment along the O3b orbit, the GSO arc is correspondingly superimposed onto the GETSAT antenna pattern. This analysis determines the GETSAT antenna gain in the direction of the GSO arc as the antenna moves to follow the O3b satellite. The EPFD ↑ limit is −162 dBW/m2/40 kHz. The spreading loss determined by the equation 𝑠𝑝𝑟𝑒𝑎𝑑𝑖𝑛𝑔 𝑙𝑜𝑠𝑠 (𝑑𝐵) = 10𝑙𝑜𝑔 (4𝜋𝑑 ) where d is the distance to a point on the GSO arc from the location on the Earth of the transmitting earth station, in one instance it is around 37,422 km. The resulting spreading loss is 162.4 dB-m2. From this, the allowed off-axis EIRP from the GETSAT antenna can be determined by adding the spreading loss to the EPFD limit. The following plot illustrates both the EPFD limit in the form of an off-axis EIRP density limit and the corresponding EIRP density from the GETSAT antenna that, when controlling the input power spectral density, is below the limit.

EIRP density dBW/40 kHz As seen by the plot above, the GETSAT operations are compliant with the EPFD↑ limits.


Document Created: 2018-08-13 08:22:51
Document Modified: 2018-08-13 08:22:51
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