Garmin International

LETTER submitted by Garmin International, Inc.

Garmin International Letter (7-17-2018)

2018-07-17

This document pretains to SAT-AMD-20180531-00045 for Amended Filing on a Satellite Space Stations filing.

IBFS_SATAMD2018053100045_1464006

Wirkinson) Barxer) KNaurR ) uur qee0 i gomeesn w Sure soon wasumoros, oc 20052 Te rnesen fax a0ares.s8e1 w waniam con us Anne Seanson se2.s89.000 Asmintougnercen cou July 17, 2018 Marlene H. Dortch, Secretary Federal Communications Commission 445 12"Street SW Washington, DC 20554 Re: Amendment to Ligado Modificd Applications, TB Docket Nos. 11—109 and 12—340; TBES File Nos, SAT—MOD—20120928—00160; SAT MOD— Dear Ms. Dontch: On behalfofGarmin International, Inc.1 subsnit the aftached lettr forthe record in the above—requested dockets and files Pursuant to Seetion 1.1206(bY2) of the Commission‘s rules, an electronic copy ofthis fetter is being filed for inclusion in each of the above—zeferenced dockets/fles. If you have any questions about this filing, please contact me. Veryfily yours, M. Anne Swan Enclosure

Witamwson) Barker) Knaver ) cur 1900 m avncer mw ) Suire acon Hasnmoron. o0 zons rer ms.oc bac rorrscass wmcoms sn cou 11 nuwe Swanton ana o oane ASmansongmanian cou July 16, 2018 via Haxp prtivery Gorard J. Waldron Covington & Burling LLP One CityCenter 850 Tenth Street, NW Washington, DC 20001—4956 Re: Amendment io Ligado Modified Applications, JB Docket Nos. 11—109 and 12—340; IBES File SAT—MOD—20720928—00160; SAT—MOD— 20120928—00161; SAT—MOD—20101118—00239; SES—MOD—20121001— 00872; SAT—AMD—20180531—00044; $AT—AMD—20180% Dear Geny: As the FCC‘s electronic system shows, on Tuly 9, 2018, Garmin Interational, nc. ied comments in the above—referenced FCC electronic dockets and files. Out of an abundance of caution, we are also providing youwith a hand—delivered copyof these comments Please let us know if you have any questions. Sincopely, PA M. Anne Swanson Enclosure

Before the FEDERAL COMMUNICATIONS COMMISSION Washington, DC 20554 Tn the Mater of ) 18 DocketNo. 12340 ) LightSquared Request to Modify Its ATC ) IBFS File Nos. SAT—MOD—20120028— Authorization ) 00160; SAT—MOD—20120928—00161; ) SAT—MOD—20101118—00239; SEs—MOD— ) 20121001—00872; SaT—AMD—20180531— ) 0004é; SAT—AMD—20180531—00045 ) LightSquared Technical Working Group ;) 1B Docket No. 11—109 Report ) CcommMENTS ARM TIONAL NC GARMIN INTERNATIONAL, INC. M. Anne Swanson of Wilkinson Barker Knauer, LLP 1800 M Street, NW, Suite 800N Washington, DC 20036 2023833342 Jis Attorneys Dated: July 9, 2018

TABLE OF CONTENTS SUMMARY. L INTRODUCTION 2 IL THE LIGADO MODIEICATION APPLICATIONS, AS AMENDED, DO NOT FULLY ADDRESS IMPORTANT CONSIDERATIONS AND RECOMMENDATIONS RAISED BY EXPERT AVIATION REGULATORY BODIES AND AVIATION PARTIES 3 HL CONCERNS ABOUT HARMPUL INTERFERENCE To HELICOPTER USE OF CERTIFIED AVIATION DEVICES, ALREADY DOCUMENTED IN THE RECORD, REMAIN UNADDRESSED .. 6 Iv. THE UNIVERSALLY RECOGNIZED 1 dB STANDARD 18 THE PROPER METRIC FOR ASSESSING INTERFERENCE «$ CONCLUSION.. L13

mmary Garmin does not oppose the Ligndo Modification Applications and recently filed Amendment, consistent with its settlement agreement with Ligedo. The aviation—related changes in the Amendment represent a positive advance on these issues. Ligndo‘s proposed adoption ofa9.8 dBW power level, as suggested recently by the U.S. Department of Transportation, is a frst step toward protecting eertifedaviation GPS devices. The proposal, however, does need to be accompanied with consideration and commitments regarding corollary restrctions on the spacing of towers/transmitters, as well as regarding certain antenna parameters — such as height, downti, and polarization. Dcereasing the power of individual ancillary terrestrial component base stations is only effective in lowering aggregate power levelsifsite spacing or tower density remains consistent with assumptions made in the original analysis. Antenna height, downtit, and polarization are also critical variables in any power calculation. Veriations from the Depertment of Transportation‘s assumptions must be considered in evaluation of a power level proposal. Without consideration and commitments regarding these issues, protection of Garmin‘s certified aviation GPS devices is not assured. The effect of Ligedo‘s proposals also needs to be considered with respect to helicopter operators‘ reliance on certified aviation GPS devices. Maximizing public availability of information about Ligndo‘s proposed ‘standoff cylinders‘" is parsmount to ensure safe implementation with respect to certified aviation GPS devices. Garmin respects the PAA‘s jursdiction and expertise regarding certified aviation issues, and grant of Ligado‘s Modified Applications and Amendment should be preceded by explicit

FAA determination and acknowledgement that operationof the proposed network is compatible with certified aviation devices. Finally, Garmin remains a strong supporter of application of a 1 dB decrease in a GPS deviee‘s carrier—to—noise density ratio ("C/N»") (the "1 dB Standard®) as a threshold determinant of harmfulinterference to the device‘s operations. Use of any elternative measure based on only user experience will failto consider the vast number of devices, uses, and environments in which GPS devices are deployed. The 1 d Standard is very relevant and appropriate to this proceeding because the design changes ongoing at Garmin in comection with the settlement agreementitself are based on ensuring thatits GPS products are not degraded by more than 1 dB C/No in the presence of Ligndo signals. Garmin agreed not to oppose the Ligado Modification Applications precisely because, speaking only for Garmin‘s devices, the technical parameters to which it agreed in the Settlement Agreement were based on its own testing using the 1 dB Standard. The 1 dB Stendard is also relevant to Garmin‘s certified aviation devices. As discussed in these comments, t receiver‘s C/Nlink budget, used in the Radio Frequency Interference analysis that underpins receiver performance standards, at imes has less than 1 dB ofmargin. As also discussed, these considerations are relevant as well to ensuring certified avistion devices‘ ability to process information from GPS augmentation systems. GPS manufacturers in the U.S. need a consistent, universal, and quantifable metrc to incorporate into their product designs and testing. Absent that, futuro product development, innovation, and the country‘s GPS and GNSS technology lead will be adversely affected. The 1 dB Standard is vitel to ensure such continued development and to ensure U.3. devices are interationally compatible and competitive.

Before the FEDERALCOMMUNICATIONS COMMISSION Washington, DC 20554 In the Matter of ) ) LightSquared Request to Modify Its ATC ) 1B DocketNo. 12340 Authorization ) ) IBFS File Nos. SAT—MOD—20120928— ) 60160; SAT—MOD—20120928—00161; ) SAT—MOD—20101118—00230; SES—MOD— ) 20121001—00872; SAT—AMD—20180531— ) 00044;SAT—AVMD.20igos31—00048 ) LightSquared Technical Working Group ) 1B DocketNo. 11—109 Report ) COMMENTS OF GARMIN INTERNATIONAL, INC. Garmzin Intemational, Inc. (*Garmin") files these comments in response to Ligado Networks LLC‘s ("Ligado‘s") amended applications for modification of ts Mobile Satellite Service (*MSS") licenses." As discussed in detail below, Garmin submits these comments to supplement the record on two points; () consideration of recommendations from aviation regulatory parties and aviation stakeholders related to contined safe operation ofGarmin‘s certified avietion products; and (i} use of a 1 dB3 decrease in the Carier—to—Noise Power Density Ratio (°C/N,") as a metric to measure interference to an affected GPS receiver (the "I dB Standard"). In processing the Modification Applications and Amendment, it is important that the FCC take both points into account. ‘ See Applications of LightSquared Subsidiary LLC, Narative, IBFS File Nos. SAT—MOD— 20151231—00000, SAT—MOD—20151231—00091, and SE8—MOD—20151231—00081 (*Modification Applications"); Ligado Networks LLC Amendment License Modification Applications, IBFS File Nos. SAT—AMD—20180531—00044 and SAT—AMD—20180531—00045 (*Amendment®), See also FCC, Satellite Policy Branch Information, Space Station Applications Accepted for Filing, Public Notice, Report No. SAT—O1321, at1 (rel. June 8, 2018). In these comments, Garmin uses the term "Ligado" to refer to Ligada‘s predecessors

L. INTRODUCTION Garmin, along with ts afflistes, is leading, worldwide provider of navigation exquipment, committed to making superior products for automotive, aviation, marine, outdoor, fitness, and sports uses that are an essential part of its customers‘ lives. Gatmin has a long history of innovation and of working with the Pederal Communications Commission("PCC" or "Commission‘), other agencies, and communications and navigation stakeholders on vita issues concerning spectrum use. Since its founding almost 30 years ago, Germin has evolved into a leading, worldwide provider of certified aviation devices, almost all of which are enabled by Global Positioning System ("GPS") technology. Garmin‘s broad, overall product portfolio serves a wide range of customers and brings critieal safety—oflife applications to the global macketplace. Garmin has long supported the development of newbroadband services in this country;it believes, however, that broadband deployment generally should not come at the expense ofharm to the nation‘s well—functioning, innovative, and economically important GPS service. With respect to the particuler service pat forward by Ligedo, Garmin entered into a settlement agreement with Ligado in which Garmin agreed not to object to Ligndo‘s proposals regarding Garmin‘s non—certified aviation and general location/navigation lines of business as long as certaintechnical parameters were met." At the same time, Garmin reserved the right to comment on issues related to certified aviation devices." n addition, Garmin and Ligado id not reach en agreement about whether the 1 dB Standard was an appropriate metric to use to evaluate * See Settlement Agreement and Releases, by and between Garmin International, I. and New LightSquared LLC and LightSquared Subsidiary LLC, t Paragraphs 9(2) & 10(2)(dated Dec. 16, 2015) ("Seitlement Agreement"),atlache to Letter from Gerard J. Waldron to Marlene H. Dortch, IB Docket Nos. 12—340 er al. (iled Dec. 17, 2015). * Settlement Agreement at Paragraphs 7(d) & 9(0).

interference, and Garmin continues to participate actively in discussions ofthe issue.* Finally, the parties to the settlement agreed that Garmin‘s execution ofthe agreement did not constitute an endorsement by Garmin of Ligado‘s proposal, and Ligado greed not to make any statement or representation to that effect." Garmin‘s agreement with Ligedo addresses its own GPS devices and does not speak to protection for all GPS devices. iL THE LIGADO MODIFICATION APPLICATIONS, AS AMENDED, DO NOT FULLY ADDRESS IMPORTANT CONSIDERATIONS AND RECOMMENDATIONS RAISED BY EXPERT AVIATION REGULATORY BOpIES AND AVIATION PArrnes The aviation industry overall has been one of the primary beneficiaries of the development of GPS, and the FOC must vigilantly continue to consider concems regarding the potential impact of Ligedo‘s proposed service on certified aviation devices. Given the essentiality of GPS for aviation, where safety—of—life is ofparemount concern, certified aviation devices must continue to operate on an interference—free basis. As Ligado has recognized, evaluation ofany interference must be based upon technical determinations by aviation safety experts at the Federal Aviation Administration (*PAA") and RTCA, Inc. Their expertise will help ensure interference—free operation. Ligado‘s latest filing proposes several aviation—related changes o its proposals and represents a positive advance on these issues." Specifically, Ligado suggests the following three changes: () lowering the power level ofis ancillary terrestrial component (*ATC®) base stations operating in the 1526—1536 MHz band to 9.8 dBW (10 W) with a +/45 degree cross—polarized * Id at Paragraph 6(). 5 1d. at Paregraph12. * See Letter from Gerard J. Waldron er al. to Marlene I1. Dortch, IB Docket No. 11—109 er at, (filed May 31, 2018), with atteched Amendment.

base station antenna; (ii) prohibiting any Ligado ATC base station anterna in this band from operating at a location less than 250 feet laterally or less than 30 fect below an obstacle clearance surface established by the FAA; and (ii) requiring Ligado to comply with reporting, notification, and monitoring obligations discussed in the Amendment." Ligado‘s proposed adoption ofthe 9.8 dBW power limit follows a recent recommendation to that effect put forward by the U.. Department of Transportation in its "Final Report"issued after a multi—year "GPS Adjacent Band Compatibilty Assessment."" This decrease in power is a first step toward protecting certified aviation receivers; however, such a step by itself,absent consideration and commitments regarding corollary restrietions on the spacing of towers and trunsmiters — inter—sit distances ("ISD‘s") between such lacations —is insufficient to protect Garmin‘s certified aviation receivers. Similarly, without consideration and commitments regarding antenna parameters —such as height, downtlt, and polasization — protection of Garmin‘s certified aviation receivers is not assured." Fizst, decreasing the power of individual ATC base stations, as Ligado has proposed, is only effective in lowering uggregate power levels ifsite spacing or tower density remins consistent with assurmptions made in the original analysis."" Changes in cell site density necessitate compensating adjustments in power levels. For instance, if tower density were to * 1d. at 1—2 & Amendment. * U.S. Department of Transportation, Globaf Positioning System (GPS) Adjacent Band Compatibility Assessment, Final Repot, at VI, 149 (Apr. 2018) (DOT/ABC Final Report"), https://www transportationgov/sites/dot gov/files/does!subdoc!86/dot—gps—adacent—bandfinal— reportapril2018.00f. * As the DOT/ARC Final Report notes, the 9.8 dBWpower level it recommended is highly dependent upon and sensitive to these antenna parameters. 74. at 148. ‘* DOT assumed ATC base stations arranged in a hexagonal grid formation with 433 meter and 693 meter ISDs. /. at Tables 5—5 & 5—9; 192—153.

increase beyond the level assumed in the DOT/ABC Final Report without sny compensating adjustment to the power level, certified aviationdevices would likely experience harmful interference. Second, antenna height and antenna downtilt are critical variables in any power calculation, and variations from DOTFAA assumptions must be considered in evaluation of a power level restriction. Ligado‘s publicly discussed proposals for it network include providing communications and data connectivity for unmanned aerial vehicles (UAVs") or drones."" Tilting or tuming antennas skyward to provide such comnectivity for UAVs would likely cause harmful interference to certified aviation devices, without compensating changes, and must be taken into account in evaluating the Modification Applications and Amendment. Accordingly, FAA—senctioned limits should be captured explicitly in PCC processing of the Modification Applications and Amendment In like manner, the polarization of transmitted signals must be expliciy addressed in evaluation ofproposed power levels. Ligado‘s Amendment is insufficiently specific with respect to the issue ofpolarization. For instance, if its ATC base stations will only be cross—polarized at the degreo specified in the Amendment, it needs to commit to that on the record. The 9.8 dBW power level recommended by the DOT/ABC Final Report only pertains to an analysis utlizing eross—polarized signals.!". Because ofthe greater sensitivity of certified aviation devices to "‘ John Crof, LightSquared Successor Fuses Space and Ground Networks for UAS, Aviation Week (Ape. 18, 2017), hitp=/avietionweek.com/eonnected—serospace/lightsquered—successor— fuses—space—and—ground—networks—uas; see also Press Relcase, Ligndo Networks, Remarks of Ligado Networks CEO Doug Smith at Politico Live "Spectrin, Innovation, and Infrastructure in the Trump Era," (June 15, 2017), bitps:/ligado.com/oress/remarks—ligado—networks—ceo—dous smith—politico—live—spectrum—innovation—infrastructure—trump—ecs/. " DOT/ABC Final Report at 149. As the DOT/ABC Final Report itsclf recommends, "a requirement for cross—polarization emissions from the base stations must be captured in any 5

vertical polarization, Ligado needs to be explicit about ts plans with respect to polarization, so power levels can be assessed accurately. T1. CONCERNS ABOUT HARMFUL INTERFERENCE To HELICOPTER USE OF CERTIFIED AVIATION DEVICES, ALREADY DOCUMENTED IN TBE RECORD, REMAIN UNADDRESSED Various parties have raised concorns, in perticuler, about the effect of Ligndo‘s proposed ATC base stations on the sefety of helicopter operations that rely upon certified aviation devices for navigational guidance."" In the Amendment, Ligado assumes aireraft will be 250 fect from one of its ATC base stations — a "standoff eylinder® of that redius."* Yet, elicopter operators have raised concems about their ability, when operating near such proposed standofeylinders, to rely on GPS—based navigation and GPS—enabled capabilitis for obstacleAertmin avoidance and position reporting with other air bound operations."" Hieense application or issuance. A vertical polarization (only) based limit must be significantly lower than 9.8 dBW." 14 " See, eg., Letter from Capt. Tim Canoll, President, Air Line Pilots Association,Interational (CALPA®), er al.to Daniel K. Elwel, IB Docket Nos. 12—340 eral, at 2 (filed June 18, 2018) ("Aviation Parties‘ June 2018 Letter®) (The leter was filed on behalfofALPA, AirbornePublic Snfety Association, Aireraft Owners and Pilots Association, Airlines for America, Association of Air Medical Services, Helicopter Association International, Helicopter Safety Advisory Conference, National Agricultural Aviation Association, Nationa! Business Aviation Association, National EMS Pilots Association, and Professional Helicapter Pilats Association}; Letter from Edward A. YorkgitisJ., Counse! for Avistion Spectrum Resources, Inc. ("ASRI®), to Marlene H. Dortch, 1B Docket Nos. 12—340 er al, at 2:3 & Attachment B (filed June 20, 2017) (*ASRI June 20, 2017 Leter®) (The letter reflected participation also by Airlines for America, Helicopter Association International, and Acrospace Industries Association) "* Amendment at 1—3. ‘* Aviation Partics‘ June 2018 Letter at 2; RTCA, Inc., "Operational Review of Ligado Networks Proposal for Standaff Cylinders (Approved by the Tactical Operation Committee December 2016)," Dee. 2016 (‘RTCA TOC Report®), at , available at hltpsorodche.rtea.ore.373elwb! blackmesh.comsites/defaultfiles/to_dec 2016 summary,pf ("Attachment 4*); ASRI June 20, 2017 Letter at 23.

These concerns about aviation safety arise for a number ofreasons. First, there currently is no codified aviation prohibition on rotorwing aireraft eatering such standoffcylinders."" Second, contrary to support for the concept in RTCA participants‘ review of Ligado‘s proposls, there is noindication that information on the location of Ligndo‘s ATC base station towers and their related standoff cylinders wl be made publicly available."" As aviation parties have recommended, "if such information is provided in a database to the operational community, and the obstacle data was {sic} incorporated into equipment performing TAWS/ETAWS function, this would begin to help ensure safery.""* Without publicly available information, a large question remains as to how helicopter pilots using certified aviation equipment will know whether or not they are operating within a standoff cylinder." On the other hand, making standoTcylinders part ofthe FAA‘s Digital Obstacle File database or other publicly available sources would go a long way to support compliance with flight planning requirements, help operators avoid standoff oylinders, and reduce the potential for inadvertent flights across or io cylinders with the attendant possibility of fight accidents."" "* See, e., 14 C.F.R § 91.119, setting forth a helicopter exemption related to minimum safe altitdes, which relies on publicly available FAA information and parameters in the rule,but makes no reference to standards uin to Ligado‘s proposal. *‘ Exhibit 1 to the Amendment provides for base station data to be submitted to the FCC and FAA with public aveilability oft information allowed only through the FCC‘s codified confidentialty procedures, which permit very limited access to confidential information "* RTCA TOC Report at 6. 1. tors remain concemed that 10,000 —20,000 StendoffCylinders may be in the (National Airspace System] and pilots may not know where they are. There is interest in understanding how operators may know where these eylinders are, and operators should be engaged to provide input into how this information would be made available to aviation stakeholders." Id ®" See FAA, Digital Obstacle Pile (DOF), httpsowww faa.gov/air trafficilightinfofaeronav (digital products/daf! (last visited July 9, 2018), which includes the following description: ("The Digital Obstacle Pile (updated every56 days) describes all known obstacles ofinterest to 7

Meximizing publicly available information is paramount because, asthe DOT/ABC Final Report noted, avi jon community concemns include the possibility that, even with full public access, "piot workload, confusion, or error could lead to airereft inadvertently entering an assessment zone [or Standoff Cylinder] and losing needed GPS functionality."*" The PCC, working closcly with the FAA, needs to focus on, and exhaustively review, these safety—related concerns. Not only did the DOT/ABC Final Report catalog them, but, as recently as several weeks ago, large number of aviation industry stakebolders, having had an opportunity to review the DOT/ABC Final Report and Ligndo‘s latest z. concluded that "the concems and safety issues of the industry have NOT been addressed.""" Similarly, the DOT/ABC Final Report itselfacknowledged that "[{Jhe FAA has not completed an exhaustive evaluation ofthe operational seenarios in developing the assessment zone(s]" or standoff eylinders."" n addition, the Report noted that "the current analyses do not include an operational avistion users in the United Stetes, with limited coverage of the Pacific, the Caribbean, Canade, and Mexico....") FAA helicopter air ambulance flight planning regulations require considezation oftermin and obstacles, and similar steps could be taken with regard to this information to ensure aviation safety. See 14 C.RR § 135.615(a), which with respect to visual fight miles (°VER®) flight planning provides for a number ofrequirements, including the following: ~Prior to conducting VER operations, the pilot in command must (1) Determine the minimum safe cruise altitude by evalusting the terrain and obstacles along the planned route of fight;(2) dentify and document the highest obstacle along the planned route of flight." "" DOT/ABC Final Report at VII.‘The DOT/ABC Final Report summarized the following additional concemns regarding stindoff cylinders: "technical and human factors issucs associated with re—initialization of GPS after loss of the signal or when the signal reception is intermittent; workload and human factors impacts on pilots to monitor and track assessment zone locations; ... and impacts to onboard and ground systems that are dependent upon GPS, such as Automatio Dependent Surveillance (ADS) Broadcast/Contract (B/C), or fixed—wing and helioopter terrain awareness warning system including obstacle alerting."14 ** Aviation Partics‘ June 2018 Leter at2. ® DOT/ABC Final Report at VIL

assessment ofthe impact ofthe assessment zone{s} in densely populated arees, which may present edditional variables, including the risk posed to people and property for operations such as UAS using certified avionies which may be required to operate within the assessment zone.""* Garmin respects the PAA‘sjurisdiction and expertise regarding certified aviation issues and related safety concerns and reiterates that grant of Ligado‘s Modified Applications and Amendment should be preceded by explicit FAA determination and acknowledgement that aperation of the propased network is compatible with certified aviation devices. TV. THE UNIVERSALLY RECOGNIZED 1 dB STANDARD IS THE PROPER METRIC FOR ASSESSING INTERFERENCE In its Amendment, Ligado again criticizes the use ofa standard metric—a 1 dB decrease in a GPS device‘s carrier—to—noise—density rati ("C/N,") (the "I dB Standard") — as a threshold determinant of harmful interference to a GPS receiver‘s operation."" Ligado‘s position overlooks the eritical differences between navigation and communication systems and the underlying engineering concepts that gover their operation. As Garmin has documented extensively in the record, the 1 dB Standard is the long—established and appropriate determinant of hermiul interference to GPS and other Redio Navigation Satelite Service ("RNSS®) receivers. As Garmin also recently highlighted, this is the case whether the 1 dB Standard is applied to out—ofband emissions (*OOBE")that emanate from services in adjecent bands but fall within the RNSS band or overload intererence that emanates from services in adjacent bands and overpowers receivers in the RNSS band."" This metric is the "n * Amendment at n.9. * Letter from M. Anne Swanson to Marlene H. Dortch, IB Docket Nos, 11—109 er af, at 2.3 (Rled May 16, 2018) ("Garmin May2018 Letter®), efring U.S. Air Porce, SMC/GP (GPS Directorate), Background Paper on Use of1—dB decrease in C/Nig as GPS Interference Protection Criterion, at 9

appropriate standard for evaluating harmful interference from adjacent band services because it suecessfully agregates increases in the noise floor from OOBE alongside degradation from overload interference, and it does so in a manner even more generous than some existing recommendations cited by the Air Force analysis endorsing use of the 1 dB Standard."" As Garmin has noted, a holistic approach is a more effective and reasonable regulatory approach to resolving this isue than a piccemeal regime, which focuses separately on different types of interference affecting the same devices."* As noted above, Garmin‘s Settlement Agreement with Ligedo specifically provides that the parties did not reach an agreement about whether the 1 dB Standard was an sppropriate metric to use to evaluate interference. That agreement also provides for specified temporal periods during which Ligedo will operate its network at reduced power levels to permit time for the design and development ofhardened receivers that will be able to tolerate interference atthe levels specified in the Settlement Agroement. The 1 dB Standard is very relevant and appropriate to this proceeding because that design change, which is ongoing at Garmin,is tself based on ensuring that its GPS products are not degraded by more than 1 dB C/No n the presence of Ligado signals. Garmin agreed not to oppose the Ligado Modification Applications precisely because, speaking only for Garmin‘s devices, the technieal parameters to which it agreed in the Settlement Agreement were based onits own testing using the 1 dB Standard 2, 6—9 (June 2017), wirw aps gov/spectrum/ABC/1 dB—background—paper.pdf and also citing Ircary & Karcan Ens., Understanding GPS, Principles and Applications, Section 5.11 .1 (Artech House, Boston, 2nd Ed. 2006) *" Garmin May 2018 Letter ut 4. "* Id; see also Letterfrom F. Micheel Swick to Marlene I1. Dortch, 1B Docket Nos, 12—340 er . at 2—11 (filed July 13, 2017); Comments of Garmin International, nc.,1B Docket Nos, 12—340 er al. at $—19 (filed May 23, 2016). 10

Without use of the universal and objective 1 dB Standard, Garmin‘s testing to cnsure compliance with the Settlement Agreement would devolve into an administratively unproductive and ineffective exercise. The same is true for testing interference to GPS devices in other contexts: without use of the 1 dB Standard, individual and vnique test scenarios would need to be developed for thousands ofuse cases — whether in automotive, aviation, marine, outdoor, fitness, or sports applications. The extensive volume of testing required across a host of subjective measurements of user—experienced "accuracy," when multiplied by the plethora oftest scenatios, would yield a vast amount ofdata that would simply be adeministratively staggering — and unlikely to demonstrate any universal trend or establishment of any other reliable metric. Regulators who reject use of the 1 dB Standard would face a daunting task and likely one that would prove inconclusive and unproductive in the end. Indeed, the volume of data accumulated in the NASCTN testing ofjusta select few devices, which relied on an approach other than the 1 dB Standard, was extensive."" As Garmin has previously discussed, these results actually provide direct and indirect support for use ofthe 1 4B metric "direct" support because the NASCTN test data showed a direct correlation between a 1 dB drop in C/MNo and degradation of the key performance indicators that were analyzed; "indirect" support by highlighting the extreme complexity olan approach like NASCTN‘s, which focused only on measuring the effect of interfering signals on selected key performance indicators of the GPS devices under test"" ® William F. Young, er al, ETE Impacts on GPS; Final Test Report, National Advanced Spectrum and Communications Test Network ("NASCTN®) (Feb. 15, 2017), bttps=npubs— «nist gou/nistpubsTechnicalNotes/NIST. TN.1952.pdf. "° Garmin May2018 Letter at 4—5. u

The 1 dB Standard is also relevant to Garmin‘s certified avietion devices, and Ligedo‘s implication to the contraryin its Amendmentis overly simplistic, There are numerous instances in which use ofthe 1 dB Standard is very relevant to designing and assessing the performance of Garmin‘s certified aviation devices. The 1 dB Standard is relevant to certiied aviation devices precisely because the receiver‘s C/No link budget is used in the Radio Frequency Interference analysis that underpins the receiver performance standards considered by RTCA and the FAA."" For instance, in the Wide Arca Augmentation System ("WAAS"), there is less than a 1 dB of margin available for additional interference beyond that which was envisioned in the existing standard."". With WAAS, Seven small changes in the C/N; ink margin can have significant adverse consequences on receiver and ultimately navigation system performance."". As litle as "a 0.4 to 0.6 dB difference in link margin, under certain seenarios, can change the WAAS word error rate by an order ofmagnitude. Loss of continulty probability is closely tied tothis and certain other key "‘ The link budget is a foundationa! equation amalgamating all system gains and fosses (including interference) from the GPS satellite to the receiver. The link budget allows system designers to ensure sufficient link margin (and safety margin) exists to accommodate the known. losses the system will encounter (2.g., path loss, interference, etc.). "" WAAS is a regional space—based augmentation system operated bythe FAA to provide extremely accurate navigation information for civilaireraf operating throughout North America. See FAA, Satellite Navigation — Wide Area Augmentation System (WAAS), hitpsy/wwwfis— .coulsboutoffice orgfheadquarters._offices/ato/service unitotechops/navservices/enss/wars (last visited July 9, 2018); see also GPS, Augmentation Systems... Wide Area Augmentation System (WAAS), epsgou/systems/auementations (last visited July 9, 2018). (Although WAAS is "designed primarily for aviation users, WAAS is widely available in receivers used by other positioning, navigation, and timing communities."). * RTCA, Inc., Assessment ofRadio Frequency Interference Relevant to the GNSS L1 Prequency Band, RTCA/DO—235B, prepared by RTCA SC—159, Mar. 13, 2008 at §2.6.3, t 23. 12

reeciver performance measures (e.g. carrier phase errar).""" Contrary to Ligedo‘s contention, the 1 dStandard is relevant to certified aviation safetyconserns as well GPS manufacturers in the U.S. need a consistent, universal, and quantifiable metric to incorporate into their product designs and testing. Without that, fature product development, innovation, and the U.S. lead in GPS and other Global Navigation Satellte System (*GNSS®) technologies will be adversely affected. The 1 dB Standard is vital to ensure such continued development and to ensure U.S. devices are internationally compatible and competiive. v. concuusion Garmin does not object to the Modification Applications and Amendment, consistent with the terms of its Settlement Agreement, which permititto make comments on issues related to certified aviation devices and the 1 dB Standard. Garmin respectfully requests that these comments be taken into account as the FCC reviews the Modification Applications and Amendment Respectfully submitted, GARMIN INTERNATIONAL, NC. By _ Mfifi__\ M. Anne Swanson of Wilkinson Barker Knauer, LLP 1800 M Street, NW, Suite 800N Washington, DC 20036 202.383.3342 Ts Attorneys Dated: July 9, 2018 " 14 13


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