Exhibit C Interference Study

0026-EX-ST-2018 Text Documents

Swarm Technologies, Inc.

2018-01-08ELS_203075

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 Exhibit C - Interference Study Interference and Electromagnetic Compatibility Study The experimental Swarm satellite network, which includes 4 satellites and 2 US earth stations1, employs the 137-138 MHz band for space to earth, and 148-149.9 MHz band for earth to space links, consistent with the US and International table of frequency allocations. To demonstrate compliance with an experimental systems obligation to operate on a non-interference basis with other authorized operators in the bands, this report provides a three part electromagnetic compatibility study with the existing authorized users. Specifically, 1) a study of compatibility with terrestrial services, 2) a study of compatibility with other satellite systems, and 3) a study of compatibility with radio astronomy services. Statement for Terrestrial and Aeronautical Mobile system compatibility ITU Radio Regulations impose power flux density (PFD) limits that trigger coordination for certain terrestrial (fixed and mobile) and aeronautical mobile systems 2 in the 137-138 MHz band and adjacent 138-143.6 MHz band . In summary the PFD thresholds that trigger coordination are as follows: ● Terrestrial Services: -125 dBW/m​2​/4KHz ● Aeronautical Mobile (R): -125 dBW/m​2​/4KHz ● Aeronautical Mobile (OR): -140 dBW/m​2​/4KHz Figure 1 shows a plot of the expected PFD at Earth’s surface for all angles of arrival over the range of possible operational orbit altitudes. Note that due to the antenna gain pattern, the PFD at ​Earth’s surface diminishes significantly as the satellite elevation increases towards 90 degrees. The gain pattern is optimal for communications at elevations 10 to 60 degrees where the majority of ground access time occurs. 1 ​The four satellites for which an authorization is sought will transmit only when within line of sight of two US earth stations, one in Palo Alto CA, and one in Atlanta GA, when commanded by the ground station. No other earth stations will transmit to the four satellites. 2 ITU RR Appendix 5, Annex 1, article 1.1.1 and 1.1.2

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 Figure 1. PFD at Earth’s surface produced by a space BEE transmission In summary, the power flux density (PFD) at the Earth’s surface produced by the Swarm satellites will not exceed -151.5 dB(W/m²) in any 4 kHz band at any angle of arrival, which is under the threshold for coordination with both terrestrial services and aeronautical mobile (OR) and therefore​ does not trigger a coordination requirement. Statement of Satellite Service system compatibility. From the ITU Space Network Systems Online (SNS), a list of satellite systems using the 137-138 MHz band and 148-150.05 MHz band was collected and shown in Table 1 and Table 2 respectively below. For each satellite system, the table indicates the administrative jurisdiction, service areas, frequency overlaps, and ultimately a disposition for a coordination requirement. Most satellites have either no frequency overlap with Swarm satellites, have no area coverage overlap, or earth stations in the USA. In addition, a search of the FCC IBFS for the 137-138 MHz band and 148-150.05 MHz band show that only Orbcomm is licensed for a space system using these space services links within the United states. In summary, only Orbcomm Satellites, NOAA N, GOES West, and the METOP satellites require some form of coordination for operations in the USA. Swarm will seek consent from both the NTIA and Orbcomm regarding those systems. It should be noted that the European METOP satellite system is a partner with

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 NOAA and presumed to be coordinated through the NTIA. However, the Swarm satellite transmissions meet the Interference Protection Criteria (IPC) for meteorological satellites3 in the 137-138 MHz band, where the total signal power from a Swarm satellite into a METOP ground receiver is never greater than -140.8 dBW for any angle of arrival and assuming a non-directional earth receive antenna with 0 dBi gain4, which is less than the IPC of -136 dBW per 150 kHz. This same IPC is applicable for the NOAA N and NOAA KLM satellites, however those systems may employ higher gain earth stations. There is no frequency overlap with NOAA KLM and therefore no interference is expected. The NOAA N earth stations may have an isotropic gain as high as 10 dBi5 and in this case the signal power from a Swarm satellite into a NOAA N ground receiver could reach -130.8 dBW exceeding the IPC. This however will be a rare situation where a Swarm satellite is transmitting at the same time the NOAA N earth station is pointed in the direction of the Swarm satellite (given a 10 dBi antenna has some directionality). In fact, potential interference conjunctions above -136 dBW/150 kHz IPC is estimated to occur less than 0.0059% of the time which just meets the IPC limit of less than 0.0063% of the time (as specified by the previously referenced ITU recommendation.) This is estimated as follows6: The Swarm transmissions will occur up to about 1.1% of the time daily over each ground station. The NOAA N satellite may transmit up to 3.3% of the time daily in the same area. A 10 dBi earth station antenna has a 6 dB beamwidth of approximately 72 degrees, which is about 16% sky coverage. This results in a potential interference conjunction exceeding -136 dBW into the earth station receiver no more than 0.0059% of the time. Therefore the experimental Swarm satellite system meets the IPC for both the METOP and NOAA N and coordination should not actually be required. Note that this estimate assumes the worst case scenario that the satellites share a similar orbit and equatorial crossing time and anything otherwise would yield a smaller conjunction percentage. The GOES WEST satellite is a Geosynchronous system with a 148.545 MHz receiver and there is no potential for interference from a Swarm earth station due to its low transmit power and path loss. The Swarm earth station transmits with a maximum EIRP density of -56 dBW/Hz and with path loss the receivable power at the Geosynchronous orbit is -224 dBW/Hz. A GOES earth station transmits with an EIRP density of about 1.7 dBW/Hz and with path loss the receivable power at the GOES satellite is -165 dBW/Hz which is 59 dB higher than a Swarm signal and interference is very unlikely. 3 ITU R-REC-SA.1027-5, Table 1, Sharing Criteria at 137-138 MHz, Interfering signal power (dBW) should not exceed –136 dBW per 150 kHz more than 0.0063% of the time. 4 The ITU SNS for METOP shows receive antenna type ND with 0 dBi isotropic gain. 5 ​The ITU SNS for NOAA N shows receive antenna type ND with up to 10 dBi isotropic gain. 6 Swarm transmissions: 1 minute duration * 4 contacts * 4 satellites / 1440 minutes/day = 1.11%, NOAA transmissions: 12 minute duration * 4 contacts * 1 satellite / 1440 minutes/day = 3.3%, NOAA earth station antenna sky coverage: PI*(72 deg beamwidth / 2)^2 / PI*(90 deg)^2 = 16%

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 There are three other satellite systems shown in the tables below deserving additional attention, IMDC, SI-SAT-BILIKIKI, and HOL-MG-A006. In all three cases there is potential frequency overlap and the USA is a designated coverage area in the ITU notices, however none of these systems have launched yet and have no US licenses or applications in at the FCC as of December 2017. The IMDC system is a single satellite by the company Innovative Solutions In Space in the Netherlands. It appears there will only be an earth station in the Netherlands. The SI-SAT-BILIKIKI and HOL-MG-A006 are both planned large Mobile Satellite Service constellations by Pangea Networks LLC and Hiber (formerly Magnitude Space) respectively. Pangea Networks is a US based company but filed their satellite system notification through the Solomon Islands administration. Hiber is a Netherlands based company and filed their satellite system notification through the Netherlands administration. In both cases, it is unknown by Swarm the status of their launch authorization licensing and construction progress. Neither entity has any space system licensing within the United States. In these tables, red colored boxes indicate frequency overlap between the respective system in the row and the Swarm BEE system. Green rows indicate some level of coordination or additional consideration is required for the system. Table 1: List of Satellite Systems in the ITU SNS, transmitting 137 - 138 MHz Satellite Country Service Area Freq Overlap Coordination Notes (max freq requirement shown) AGILE Italy XVE 138 None Equatorial NGSO, Kenya ES no orbital access to USA. ATS-5 USA GEO ...137.365 None GEO, no frequency overlap NC ES EUTELSAT-48E France GEO ...137.230 None GEO, no frequency overlap Belgium ES IMDC Nether XAA, 137.9-138 None Not launched yet? lands Netherland ES E-S, S-E No US license/stations Innovative Solutions In Space IMP-J USA AK, NC ES ...137.995 None Inactive, 1970’s LEOTELCOM-1 USA XAX ...137.325 Orbcomm No frequency overlap (world) Consent LEOTELCOM-2 USA XAX ...137.928 Orbcomm To be coordinated with Consent Orbcomm LEOTELCOM-5 USA XAA ...137.655 Orbcomm No frequency overlap Consent MCSCS China XAA (world) ...137.525 None No frequency overlap METEOR-3M Russia XAA ...137.975 None deactivated March 2006 METOP France XAA ...137.988 None To be coordinated w/ NTIA? IPC met IPC met NOAA N USA XAA ...137.932 NTIA consent To be coordinated w/ NTIA IPC met IPC met NOAA-KLM USA XAA ...137.793 None No frequency overlap RS-D2 India IND (India) ...137.550 None No area or frequency overlap

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 SAUDISAT-1C Saudi ARS ...137.525 None No area or frequency overlap Arabia (Saudi Arabia) SAUDISAT-2 Saudi ARS ...137.513 None No area or frequency overlap Arabia SEO India IND ...137.990 None No area overlap, 1980’s BHASKARA-1 SEO India IND ...137.990 None No area overlap, 1980’s BHASKARA-2 SI-SAT-BILIKIK Solomon XAA 137-138 None Not launched yet I Island (1 MHz) No US license/stations (300 satellites) Pangea Networks SROSS-1 India IND ...137.690 None No area or frequency overlap 1990’s Table 2: List of Satellite Systems in the ITU SNS, receiving 148 - 150.05 MHz Satellite Country Service Area Freq Overlap Coordinatio Notes (closest freq n shown) requirement AGILE Italy XVE 149.0 None No area overlap space to 2 MHz Equatorial orbit space link Leotelcom-1 space link ATS-5 USA GEO 148.26 None No frequency overlap NC ES 30 kHz CASSIOPE-1A Canada XAA 150.005... Tx None No frequency overlap GOES West USA GEO 148.545 NTIA To be coordinated w/ NTIA Wallops VA 30 KHz Consent IPC met IPC met HOL-MG-A006 Nether XAA 148-149.9 None Not launched yet (140 satellites) lands 12 kHz No US license/stations Magnitude Space (Hiber) IMP-J USA AK, NC ES 148.98 None No frequency overlap 30 kHz Inactive, 1970’s IPS Nether HOL ...148.118 None No area or frequency overlap lands IRS-1B, 1E India India 149.522 None No area overlap 12 kHz KITSAT-3 Korea Korea 148.025,148.9 None No area or frequency overlap 20 kHz LEOTELCOM-1 USA XAX 148-150.05 Orbcomm To be coordinated with (world) Consent Orbcomm LEOTELCOM-2 USA XAX 148-148.905 Orbcomm To be coordinated with Consent Orbcomm LEOTELCOM-3 USA XAX 149.81-149.9 None No frequency overlap (world) LEOTELCOM-5 USA XAA 148-150.05 Orbcomm To be coordinated with Consent Orbcomm LUX-NGSO Luxemb XAA 149.0-151.0 None No frequency overlap -1/2/3 ourg MCSCS China XAA (world) 149.025 None No frequency overlap 44 kHz No US stations

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 RS-D2 India IND (India) ...148.265 None No area or frequency overlap S4P Swiss HOL, SUI 148.2635 None No area overlap -148.5865 SAUDISAT-1C Saudi ARS 149.025 None No area or frequency overlap Arabia (Saudi Arabia) 44 kHz SEO India IND ...148.265, None No area or frequency overlap BHASKARA-1 148.595... 1980’s SEO India IND ...148.265, None No area or frequency overlap BHASKARA-2 148.595... 1980’s SI-SAT-BILIKIK Solomon XAA 149.025 None No frequency overlap I Island 100 kHz No US license/stations SROSS-1,-3 India IND 149.272... None No area or frequency overlap TELEOS-1 SNG SNG 148.6875... None No area or frequency overlap TSYKADA Russia XAA 149.903... None No frequency overlap YOUTHSAT India XAX 149.995... None No frequency overlap Radio Astronomy Service protection Pursuant to the ITU Radio Regulations 5.208A, Swarm BEE’s meet the ITU 7 recommendations to avoid interference with the nearby Radio Astronomy Service (RAS) band (150.05-153 MHz). The space BEE’s transmit only in the 137-138 MHz band and out of band emissions are minimized by digital modulation techniques and filtering with at least 85 dB spectral roll-off 8 at 150 MHz resulting in a power flux density (pfd) at Earth’s surface not exceeding -272.5 dB(W/(m​2​ · Hz)) thereby meeting the RAS 9 protection criteria of -259 dB(W/(m​2​ ·Hz)) . Ground BEE’s transmit in the adjacent band 148-149.9 MHz and employ the same digital modulation techniques and filtering as Space BEE’s with at least 70 dB spectral rolloff at 150.05 MHz from a transmit frequency at 148.5 MHz. Nevertheless Ground BEE’s will be positioned at a distance or otherwise obstructed such to prevent line-of-site observations by a Radio Astronomy site using the 150.05-153 MHz band10 and resulting in a signal attenuation that meets the RAS interference protection criteria. In addition, the frequency of transmissions from the Swarm earth stations is much less 7 ​ITU Radio Regulations, Resolution 739 (Rev. WRC-15) and Recommendation ITU-R M.1583. 8 Measured performance at 150 Mhz is -86 dBc within the limits of the test equipment and likely exceeds this performance in the RAS bands. -80 dBc occurs at 3 Mhz from the carrier. 9 ​As specified in ITU-R M.1583, the protection criteria is -238 dB(W/m​2​) in a 2.95 MHz reference bandwidth and as recommended in ITU-R RA.769-2 Table 1, the threshold for harmful interference is -259 dB(W/(m​2​ · Hz)) at a center frequency 151.525 MHz. 10 Recommendation ITU-R RA.769-1 specifies “above about 40 MHz sharing may be practicable with services in which the transmitters are not in direct line-of-sight of the observatories”.

Swarm Technologies Inc. Exhibit C to FCC Form 442 Jan 04, 2018 than 2% of the time11 which also meets the RAS protection criteria12. Conclusion The experimental satellites and US earth stations pose no risk of creating harmful interference with any known system with the exception of Orbcomm. As represented above, Swarm satellite transmissions are compliant with the frequency allocation tables and meet PFD based protection criteria for terrestrial systems and RAS as well as meteorological satellite systems. Swarm will seek specific consent from Orbcomm to mitigate any potential for interference with their system. 11 The experimental transmissions are at a maximum of 1 minute durations 16 times per day (~1.1% of the time). This accounts for 4 satellites with up to 4 contacts each per day. 12 ITU RR 2016, Resolution 739, article g, and ITU-R RA.1513-2, article 2.


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Document Modified: 2019-04-24 11:04:24
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