Iridium PTD.pdf

PETITION submitted by Iridium Constellation LLC

Petition to Deny of Iridium Constellation LLC

2017-06-26

This document pretains to SAT-LOA-20161115-00117 for Application to Launch and Operate on a Satellite Space Stations filing.

IBFS_SATLOA2016111500117_1241532

Before the Federal Communications Commission Washington, D.C. 20554 In the Matter of File No. Audacy Corporation SAT−LOA−20161115−00117 Application for Satellite Space Station Authorizations PETITION TO DENY OF IRIDIUM CONSTELLATION LLC INTRODUCTION In response to the FCC’s processing round opened on July 15, 2016, 1 Audacy Corporation (“Audacy”) applied for authority to launch and operate a non-geostationary satellite orbit (“NGSO”) system in the fixed satellite service (“FSS”) and inter-satellite service (“ISS”). 2 The proposed system would use three medium Earth orbit (“MEO”) satellites and three gateway earth stations to provide bidirectional inter-satellite relay services to other spacecraft 3 On May 26, 2017, the Commission accepted Audacy’s application for filing with respect to certain frequencies, including all 1,300 MHz of K-band spectrum Audacy seeks to use for ISS operations. 4 Iridium Constellation LLC (“Iridium”) hereby petitions to deny Audacy’s application because it appears that Audacy will be unable to coordinate its inter-satellite links 1 Cut-Off Established for Additional NGSO-Like Satellite Applications or Petitions for Operations in the 10.7- 12.7 GHz, 14.0- 14.5 GHz, 17.8-18.6 GHz, 18.8-19.3 GHz, 27.5-28.35 GHz, 28.35-29.1 GHz, and 29.5-30.0 GHz Bands, Public Notice, DA 16-804 (rel. July 15, 2016). 2 Application for Satellite Space Station Authorizations of Audacy Corporation, IBFS File No. SAT−LOA−20161115−00117 (filed Nov. 15, 2016). 3 See id. at Attachment “Narrative Exhibit,” pp. 11-13 (“Audacy Narrative”). 4 Applications Accepted for Filing, Cut-Off Established for Additional NGSO-Like Satellite Applications or Petitions for Operations in the 12.75-13.25 GHz, 13.85-14.0 GHz, 18.6-18.8 GHz, 19.3-20.2 GHz, and 29.1- 29.5 GHz Bands, Public Notice, DA 17-254 (rel. May 26, 2017). On June 16, 2017, the Commission accepted Audacy’s application for filing with respect to the remaining frequencies. See Satellite Space Applications Accepted for Filing, Public Notice, Report No. SAT-01245 (rel. June 16, 2017). 1

with Iridium’s inter-satellite links as required by the Commission’s rules, and as Audacy promised in its application. I. BACKGROUND Under the architecture proposed in the application, the Audacy network would relay data from multiple customers’ satellite networks through ground infrastructure operated by Audacy. 5 In the return direction, low Earth orbit (“LEO”) spacecraft operated by an Audacy customer would transmit data to the nearest satellite in the Audacy constellation using K-band spectrum designated for ISS, including the 22.55-23.55 GHz band. 6 The Audacy satellite then would route the data to an Audacy gateway either directly, or indirectly by first transmitting the communication to another Audacy satellite over V-band ISS spectrum, before delivering it to the customer’s terrestrial point-of-presence. 7 Forward-link communications would follow the same path in reverse. 8 Iridium operates an NGSO constellation of sixty-six cross-linked LEO satellites, and is now in the midst of launching its second-generation constellation, Iridium NEXT. 9 Both the current and the new Iridium constellations use 23.18-23.38 GHz for inter-satellite links. 10 Audacy’s proposed ISS frequencies include the 200 MHz of ISS spectrum used by Iridium. Unimpeded access to this 200 MHz of ISS spectrum is essential to the operation of the Iridium network. Using the 23.18-23.38 GHz band segment, Iridium’s crosslinks complete a 5 Audacy Narrative at 11-21. 6 Id. at 22. 7 Id. 8 Id. at 24-28. 9 See Iridium Constellation LLC, Application for Modification of License to Authorize a Second-Generation NGSO MSS Constellation, Order and Authorization, 31 FCC Rcd. 8675 (2016). 10 Id. ¶¶ 3, 45(f). 2

large, fully meshed network, providing space-based backhaul connections that can route user communications efficiently to and from nearly any destination in the world. This allows Iridium to provide secure, reliable, and low latency service over a footprint unmatched by other mobile satellite systems—and to deliver mission-critical commercial, public safety, and U.S. military communications all across the globe. II. THE COMMISSION SHOULD DENY AUDACY’S APPLICATION TO OPERATE IN THE 22.55-23.55 GHZ BAND. Under the Commission’s rules, ISS systems “must operate in accordance with conditions” specified in 47 C.F.R. § 25.279(b). 11 One such condition provides that applicants for authority in the ISS “coordinate their proposed frequency usage with existing permittees and licensees in the inter-satellite service whose facilities could be affected by the new proposal in terms of frequency interference or restricted system capacity.” 12 Existing licensees “being coordinated with [are] not obligated to suggest changes or re-engineer an applicant’s proposal in cases involving conflicts.” 13 Consistent with its obligations as an ISS applicant, Audacy committed in its application to “coordinate with incumbent and planned operators on a case-by- case basis to ensure spectrum sharing and compatibility.” 14 Audacy is an applicant for authority in the ISS. Iridium is an ISS licensee whose facilities could be affected by Audacy’s proposal in terms of frequency interference. It is incumbent on Audacy, therefore, to coordinate with Iridium, and Iridium is not obligated to suggest changes or to re-engineer Audacy’s proposal. 11 47 C.F.R. § 25.279(b). 12 Id. § 25.279(b)(2). 13 Id. 14 Audacy Narrative at 78. 3

The problem is that Audacy’s proposal appears to make co-frequency coordination with Iridium’s inter-satellite links infeasible. As an initial matter, the risk to Iridium’s network from Audacy’s non-traditional use of inter-satellite links would be substantial. Audacy’s network concept is to relay, from MEO, backhaul communications to and from multiple LEO spacecraft over the entire globe. Moreover, Audacy’s application makes clear that it aspires to use K-band inter-satellite links on a continuous basis to communicate with the large number of customer satellites to whom Audacy hopes to provide service. This creates substantial likelihood of harmful interference at the Iridium receiver. When satellite systems have limited territorial overlap, it may be possible to avoid interference through geographic isolation. In this case, however, geographic isolation between Iridium’s and Audacy’s inter-satellite links would be impossible to achieve. Audacy proposes to provide full global coverage with its MEO satellites. Iridium’s LEO satellite constellation also provides global coverage. With global coverage on both sides, there is no geography to isolate. The potentially large number of unidentified client LEO systems creates an additional challenge to coordinating with Iridium. Because the size, location, and operating parameters of the client LEO systems are unknown, Audacy cannot determine that communications with client satellites would not interfere with Iridium. At a minimum, Audacy would not be able to communicate with client satellites until the client applies for and receives corresponding authority to operate in the ISS, and each client coordinates with Iridium together with Audacy. Even after Audacy clients are identified, however, coordination between Iridium and each operator and Audacy would be perhaps incurably complex given the large number of spacecraft that may be involved. 4

These irreconcilable conflicts with Iridium’s existing system provide enough reason for the Commission to deny Audacy’s application to operate in the 22.55-23.55 GHz band. But Audacy’s flawed technical analysis, which severely understates the potential for interference, provides an additional and independent reason for the Commission to do so. First, Audacy’s narrative only addresses the potential of interference in the forward direction, i.e., from the Audacy relay satellite to the client LEO spacecraft. It simply ignores the return link when the client LEO spacecraft transmits to the Audacy relay satellite. But these return links are at least as likely to produce unacceptable interference to Iridium’s crosslinks as the forward link from Audacy’s relay satellites. Second, Audacy’s incomplete analysis seems to have been performed incorrectly. In Audacy’s Table 9, entitled “Relay  NGSO interference analysis,” Audacy conducts a representative analysis of interference levels from forward-link operations. 15 Iridium was not able to replicate the notional interference calculations in Audacy’s narrative, because it appears that Audacy’s interference results were calculated improperly, resulting in a severe underestimation of the actual interference level. More specifically, it appears that Audacy may have converted received PFD to power density incorrectly, by subtracting the victim LEO satellite receiver antenna gain, instead of adding it, and by neglecting to take into account the signal wavelength. Audacy’s original table and values, along with the values Iridium believes are correct, are shown below. 15 See id. at 75-78. 5

Corrected Audacy Table 9 Audacy Analysis with Incorrect Values Analysis with Corrected Values Comment Parameter Units Worst-Case Go Rx Noise Figure dB 4 (Estimated) 4 (Estimated) Go Rx Noise Density dBW/MHz -146.8 (To = 60 K) -146.8 (To = 60 K) Go Rx Gain dBi 35.0 (Estimated) 35.0 (Estimated) Go Rx Isolation dB 0.0 0.0 This PFD is valid, given Audacy Relay satellite transmit EIRP and separation distance from Relay 2 Relay PFD at Go dBW/m /MHz -129.4 -129.4 satellite and victim LEO satellite To convert PFD to Power Density, PD: 2 =-129.4 +35+10*LOG(1.35E-05) = Pd = PFD (dBW/m /MHz) + Go Rx Gain Power Received at Go dBW/MHz -164.4 -143.1 (dBi) + 10*log(λ /4π) (dB-m2) 2 Correctly calculated interference Interference : Noise dB (%) -17.6 (0.02) +3.7 (234) level exceeds receiver noise density Interference Degradation dB 0.07 +5.2 CONCLUSION For these reasons, the Commission – based on the current record – must deny Audacy’s application to operate in the 22.55-23.55 GHz band. Respectfully submitted, _______________________________ Maureen C. McLaughlin Scott Blake Harris Vice President, Public Policy V. Shiva Goel IRIDIUM CONSTELLATION LLC HARRIS, WILTSHIRE & GRANNIS LLP 1750 Tysons Boulevard, Suite 1400 1919 M Street, NW, 8th Floor McLean, VA 22102 Washington, DC 20036 (703) 287-7518 (202) 730-1313 June 26, 2017 6

Before the Federal Communications Commission Washington, D.C. 20554 In the Matter of File No. Audacy Corporation SAT−LOA−20161115−00117 Application for Satellite Space Station Authorizations DECLARATION OF SCOTT BLAKE HARRIS IN SUPPORT OF PETITION TO DENY OF IRIDIUM CONSTELLATION LLC I, Scott Blake Harris, declare under penalty of perjury that the following is true and correct: 1. I am outside counsel to Iridium Constellation LLC. 2. I have read the foregoing “Petition to Deny of Iridium Constellation LLC.” I have personal knowledge of any facts alleged therein of which the Federal Communications Commission may not take official notice, and those facts are true and correct to the best of my knowledge, information, and belief. Executed on June 26, 2017 7

CERTIFICATE OF SERVICE I hereby certify that a true and correct copy of the foregoing Comments of Iridium Constellation LLC was sent by mail on this 26th day of June 2017, to the following: Ulises R. Pin Timothy Bransford Denise Wood Morgan, Lewis & Bockius LLP 2020 K Street, N.W. Washington, D.C. 20006 Counsel for Audacy Corporation /s/ Elizabeth Marley Elizabeth Marley


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Document Modified: 2019-04-14 01:15:41
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