Exhibit C Interference Analysis

0158-EX-CN-2019 Text Documents

Swarm Technologies, Inc.

2019-03-08ELS_224989

Swarm Technologies Inc. Exhibit C to FCC Form 442 March 8, 2019 Exhibit C - Interference Study Interference and Electromagnetic Compatibility Study The experimental Swarm satellite network, which includes 3 satellites and 2 US earth stations1, employs the 137-138 MHz band for space to earth and 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, the report includes: 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 at the operational orbit altitude. 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 three satellites for which an authorization is sought will transmit only when within line of sight of two US earth stations, one in Los Altos CA, and one in Atlanta GA, when commanded by the ground station. No other earth stations will transmit to the three 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 March 8, 2019 Figure 1. PFD at Earth’s surface produced by a satellite transmission In summary, the power flux density (PFD) at the Earth’s surface produced by the Swarm satellites will not exceed -145 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 (R or OR) and therefore​ does not trigger a coordination requirement. Statement of Satellite ServiceSystem Compatibility From the ITU Space Network Systems Online (SNS), a list of satellite systems using the 137-138 MHz band was collected and shown in Table 1. 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 have no apparent earth stations in the USA. In addition, a search of the FCC IBFS for the 137-138 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, and NOAA N require some form of coordination for operations in the USA. Swarm will seek consent from both the NTIA and Orbcomm regarding those systems.

Swarm Technologies Inc. Exhibit C to FCC Form 442 March 8, 2019 The Interference Protection Criteria (IPC) for meteorological satellites3 in the 137-138 MHz band is -136 dBW per 150 kHz. This IPC is applicable for the NOAA N and NOAA KLM satellites. 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 dBi4 and in this case the signal power from a Swarm satellite into a NOAA N ground receiver could reach -132.8 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 0.00037% of the time which meets the IPC limit of less than 0.0063% of the time (as specified by the previously referenced ITU recommendation.) This is estimated as follows5: The Swarm transmissions will occur less than 0.069% 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 0.00037% of the time. Therefore the experimental Swarm satellite system meets the IPC for 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. There are two other satellite systems shown in the tables below deserving additional attention, IMDC and SI-SAT-BILIKIKI. In each of these two 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 no US licenses or applications were submitted to 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 is a planned large Mobile Satellite Service constellation by Pangea Networks LLC. Pangea Networks is a US based company but filed their satellite system notification through the Solomon Islands administration. the status of their launch authorization licensing and construction progress is unknown by Swarm, and Pangea has no space system licensing within the United States. 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 NOAA N shows receive antenna type ND with up to 10 dBi isotropic gain. 5 Swarm transmissions: 2 second duration * 10 contacts * 3 satellites / 1440 minutes/day = 0.069%, 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 March 8, 2019 In these tables, red-colored boxes indicate frequency overlap between the respective system in the row and the Swarm satellites. 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 ...137.1 None No frequency overlap 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 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

Swarm Technologies Inc. Exhibit C to FCC Form 442 March 8, 2019 Radio AstronomyService Protection Pursuant to the ITU Radio Regulations 5.208A, Swarm's satellites meet the ITU recommendations6 to avoid interference with the nearby Radio Astronomy Service (RAS) band (150.05-153 MHz). The satellites 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 7 at 150 MHz resulting in a power flux density (pfd) at Earth’s surface not exceeding -265 dB(W/(m​2​ · Hz)) thereby meeting the RAS protection criteria of -259 dB(W/(m​2​ · Hz))8. The experimental ground stations share the same frequency and out of band suppression characteristics. Ground stations will be positioned at a distance or otherwise obstructed such to prevent line-of-sight observations by a Radio Astronomy site using the 150.05-153 MHz band9 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 than 2% of the time10 which also meets the RAS protection criteria11. 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. 6 ​ITU Radio Regulations, Resolution 739 (Rev. WRC-15) and Recommendation ITU-R M.1583. 7 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. 8 ​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. 9 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”. 10 The experimental transmissions are at a maximum of 2 second durations 30 times per day (~0.069% of the time). This accounts for 3 satellites with up to 10 contacts each per day. 11 ITU RR 2016, Resolution 739, article g, and ITU-R RA.1513-2, article 2.


Document Created: 2019-03-07 14:05:06
Document Modified: 2019-03-07 14:05:06
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