Attachment April 12 2006 SUPP

This document pretains to SES-LIC-20051028-01494 for License on a Satellite Earth Station filing.

IBFS_SESLIC2005102801494_536516

118 en oven tic, tm tove \maegan o. ssoserine o asn en—zms rae aon esnz o nen LATHAMeWATKINS« Ts..on dnage mverime REeceIveD — FC mdns hoon An April 12, 2006 arR 1 2 2006 Ts Soies oooms: Save By HAND pELIVERywnloomaerebees > hoctopmitial hoalilien NerJeney vimnegen 05 Marlene H. Dortch Secretary Federal Communications Commission 445 12th Street, N.W. Washington, D.C. 20554 Attn: Scott Kotler, International Bureau Trang Ngtiyen, International Bureau Re: ViaSat, Inc. Supplemental Fili Call Sign E05031 File Nos. SES—L1C—2005102 SES—AMD—2 Dear Ms. Dortch: ViaSat, Inc. hereby submits the enclosed coordination agreement with National Science Foundation to supplement the above—referenced pending application. 1fyou have any questions regarding this submission, please contact the undersigned at (202) 637—1056. Respectfully submitted, Enclosure nowsier

eariirznes. rais res—asz—s02« astronow orviston mce on Dmvision or AstRonomicat Sciences Nationat. Science Founbation 4201 WiLson Bourevaro AruiNaTon, Vircinia 22230 USA FAX Cover Shoot Telefax Number: (703) 292—9034 Date: April 12, 2006 Number of pages (including cover shoet: 16 To: Elizabeth Park, 202—637—2201 From: Dr. Tomas Gergely, NSF Phone: Tos—202—4896 FAX: 7os—202—0034 E—mail: tgergoly@nef.gov

earrzrzens xsise res—ass—sess ssteowmy orviston mage ez EXECUTION COPY A Coordination Agreement Between the National Science Foundation (bereinafter "NSE") and ViaSat, Inc. (bereinafter "ViaSat") for Operation of the ViaSat Arclight AMSS and Radio Astronomy Sites Jointly Sharing the 14.0 — 14.5 GHz—Band ViaSat secks to cense and operate aeronantical mobile—satelitestations (AMSS) over the Continental United States (CONUS) on a secondary basis in the 14.0 to 14.5 GHz FSS band: "The AMSS terminals are part ofthe Arclight® satellte communications system aboard general aviation and commercial aireraft using transponders in the Geostationary Satelite Orbit (GSO) arc. This Coordination Agreement has been prepared in complianee with the rules ofthe Rederal Communications Commission (FGC) and the recommendations ofthe Intemnational Telecommunication Union (FTU) in effect following the World Radiocommunication Conference WRC—03. 1. Overview 1.1 The 140 — 14.5 GHz—band has been allocated to mobile—satelie service, now including seronautical mobile—satellte service, on a secondarybasis, provided thatairbomne earth stations (ABS) include specific protection to the radio astronomy service within the 14.47 —14.50 GBtz—band 1.2 The 14.47 — 14.50 GHz—band is allocated to radio astronomy service on a secondary basis. 1.3 ViaSat filed an application forlcense authorization with the FCC on October 28, 2005, File Number SES—LIC—20051028—01492, to operate up to 1000 technically identical AES units n the 11.7—~ 12.2 and 14.0—14.5 GHz—bands. 1.4 These ABSs receive from, and transmit t, the sametransponder under control ofa Ground Barth Station (GES) and Network Operations Center (NOC). They, and the terrestril network to which they are connected, comprise the ViaSat Arclight system. 1.5 This Coordination Agreement has been prepared to ensure that operation ofthe Arclight AESs conform to the requirements othe FCC and the recommendations ofthe TTU for radioastronomy protection. 1.6 ViaSat has th authority to negotiate and sign this Coordination Agreement for the Arclight system and the Electromagnetic Spectrum Unit ofthe NSF has the authority to negotiate and sign this agreement for the Radio Astronomy sites listed in Section 2.1. NSF Coordination Agreement 1

ew/ra/zens raise res—ass—seme sstrowow prviston mrce es EXECUTION COPY 2. National Science Foundation Radio Astronomy Observatork 2.1 Site Table Following is a listofNSF supported Radio Astronomy sites within the United States and itsterritories which may make observations in the 14.47 —— 14.50 GHz—band. Two differentlevels ofprotection aze provided for ts sites during periods when they are performing observations, as detiled in Section 3. Obsmatay Tadude Longids oms) Oms) ' Green Bank, WV (National Radio Quiet Zone) 3e 2s 5o 795024 Socorro, NM se 0643 1073704 National Astronomy and Tonosphere Conter site: Arecibo, PR (tentative addition to site Ti 182046 6645 11 * ArayCONUS: Kitt Pesk, AZ 3157221113642 Owens Valley, CA sriese 181634 N. Liberty, TA a1de 17 913426 Hancock, NH 425601 71 59 12 Los Alamos, NM ss 4630 106 1442 Pie Town, NM 34 18 04— 1080707 Fr. Davis, TX 3038 06 1035639 Brewster, WA as o7 ss 1194055 VeryLon sites. offs « Mauna Kea, HI 1948 161552720 St Croie, VI 17asa1 etss s 2.2 Additional Radio Astronomy Sites Additional Radio Astronomy sites may be added to the s in 2.1 above. NSF shall give ViaSat t last two months notice oadditional sites which may be using the 14.47 — 14.50 GHz—band for observations or of changes in statusto the existing sites. NSF Coordination Agreement 2

eafrz/zons rarss resass—sese astrowom prviston reoe. o« EXECUTION COPY 3. Operational Coordination Agrecment NSF and VIASAT agree to the following: 3.1 The purpose ofthis Coordination Agreement is to provide protection to the Radio Astronomy sites listed in th site Table of2.1 during periods ofobservations in the 1447 —14,50 GHz—band to h following aggregate power flux density (pFd) levels within that band: a.. ~221 dBWim‘FHz, for the Green Bank, Socotro and Arecibo sites b. —189 dBW/m‘/Hz, for the VLBA sites 3.2 This Coordination Agreement should be reviewed periodically by all signstories tothe agreement beginning within a year fllowing commensement of service by ViaSat under an operational Hiease from the FCC. The purpose ofthe review is to assess the effectiveness ofthis agreement as well as to update his, or successor operational agreements, as applicable. 3.3 Each party shall inform the other party in a timely manner ofchanges in the points of contact as defined in Section 5. ViaSat agrees to: 3.4 Cease transmissions fom AESs in the 14.47 — 14.50 GHz—band, within line—ofsight of Radio Astronomy siteslited in the site Table of2.1, during periods of notified radio astronomy observations. 3.5 Control the ABS transmitters so that the pfd levels in the 14.47—— 14.50 GHz—band, produced by individual ABS, measured at the radio astronomy sites during periods of notified observation, do not exeeed the following levels: . pd (dBWin!/MHz)=—182+0.5 * 0. ford <10° pid (CBWinPMH® 177 for 10° <0 =90° where 0 is the angle ofarival atthe receiving site "This will be accomplished by operating on transponders that are sufficiently removed from the RA frequencies and by reducing or ceasing AES transmissions in the vicnity of Radio Astronomy sites during periods ofnotified radio astronomy obscrvations. 3.6 Respond expeditiously to an NSF request for protection in accordance with Sections 344 and .5 ofany sit listed in ste Table 2.1, for observations of specialtransient celestial objests (comets,supemovae and other celestial objects ofheretofore unknown type) that are not anticipated by the observation schedule in Section 3.7, and that may need to be sccommodated on shorter notice. Requests for such observations are not expected to exceed 40 hours per calendar year. NSF Coondination Agreement 3

ea/zz/zo0s. rnice 7os—asz—s024 sstroway piviston mcz os NSF agrees to: 3.7 Maintain an observation schedule in the 14.47 — 14.50 GHz—band for the siteslited in the site Table2.1 and provide this schedule via both e—mail and fix to the designated points of contact isted in Section 5.2 below at least 7 days prior tothe scheduled observations. 3.8 Provide through NAIC and NRAO full access to ViaSat representatives to data relating to interference in the 14.47 — 14.50 GHz—band that may be collected during observations thatfill within the scope ofthis Coordination Agreement. 4. Astignme and 4.1 This Coontination Agreement shall be binding upon the parties hereto and thei respective suecessors and assigns. 4.2 This Coontination Agreement may be terminated by either party upon 6 months of 5. of 5.1 Points of contact conserning this Coordination Agreement: Contact: Dr. Tomas E. Gergely Name: Keven Lippert "Title: Electromagnetic Spectrum Manager ‘Tite: Associate General Counsel Organization: National Science Foundation Organization: VisSat, Inc. Address: 4201 Wilson Boulevard, Room 1030 Address: 6155 El Camino Real Artington VA 22230 USA Curlsbed, CA 92009—1699 Telephone: (703) 29244896 Telephone: (760) 476—2214 Facsimile: (703) 292—9034 Facsimile: (760) 929—3926 email: e—mail: kevenlipper@viasatcom 5.2 Points of contact for Radio Astronomy observation schedules: Contact: Dr. Harvey Liset Name: Dary! T. Hunter, PE. "Title: Director, Spectrum Management Title: Sr.Sysiems Engineer Organization: NRAO Organization: VieSat, Inc. Address: 520 Edgemont Rd. Address: 6155 El Camino Real Charlottesville, Va. 22903 Carished, CA 92009 Telephone: (434) 296—0344 Telephone: (760) 476—2583 Facsimile: (434) 296—0278 Facsimile: (760) 929—3941 e—mail: blis@@nrao.edu e—mail:dary|hunter@iasst.com NSF Coordination Agreement

ea/r3/zeas raisa res—2s0—sese astronomy orvzszon mae. oo EXECUTION CoPY & Sinatures This Coordination Agreement is being made in good faith by both parties and is effective on the date on which the later part signs t. It may be executed in one or more counterparts, each ofwhich will be deemed an original, and all ofwhich together will constitute one and the same instrument. For the National Science Foundation: For ViaSat, nc. By: /\nLC"A,/? ‘sw%/‘zfi Name: Dr. Tomas Gergely Name: Keven Lippert Tite: Electromagnetic Spectrum Manager Title: Associate General Counsel Date: q/aj/,oé Date: 2/12/0g NSF Coontination Agreement 5

evazizems usces res—ner—sese astronow prviston rece. or ExEcurion cory Attachment A The ViaSat, Inc. AMSS Plan To Protect Radio Astronomy Overview There are three methods that willbe employed to provide protection to the NSF sites 1 from interference by ABS terminals. These methods are: frequency selection; ABS transmission power control; and geogrephical avoidance oftcoordinated sites. There are two different protection criteia identified by the NSF, Interference thresholds for the Arecibo, PR, Green Bank, WV, and the Socorro, NM sitesare —221 dB(W/(m— Hz)), and the Very Long Baseline Array(VLBA) sites are —189 dB(W/(m‘ « H2)) — aggregate power flux density. Method One — Frequency Sclection Figure 1 depicts the transponder frequency arrangement for SES Americomn‘s AMC—6, a typical Ku—band Fixed Satelite Service (RSS) satellte operating in a geostationary orbit : providing service to the continental United States (CONUS). ustek wan m wa wne ww som on um soe som ues| ue h pol 11 ] Lo .3..11..... i g 7 T.T Y o# hm om sn um se ow vot L 1 E..1L...IL.1C—31 = a= 2ov o Extnded Emmueqyiec Dountak Covnm ons m ie m mse mss n ree ie me ues oue e vesl_ _94 } Mowo hael b—vl havel Reonad Grd B $ 1.3 14 C soomaui t T T To o9 To o% 9 m w( sn e we ne ns me me ie us me on ce me npot L l comconcon on h on oc oc e n iD &~ Cao| To T y i w w ow u w m ao% Fmumeyme

narizreons roiue rescass—sose «strovow prviston mee. e EXxECUTION cory ARS TnnanitPSD ad Spoctcaton on mm sns wes 1g6 uen ue w ue soe wom use wen uen Immainoi —ot tount uin mmn t P0ienss 04 08 38104 Tamgcee n Figure 3 AES GMSK Spectral Ontpot Po: . Method Two — AES Transmission Power Control The ViaSat AMSS system has been designed to be compliant with TTU—R. Recommendation M.1643, Anner 1, Part C, which has been accepted and implemented y the Federal Communications Commission subsequent to the World Radiocommunication Conference WRC—03. Figure 4 shows the limitations imposed on a single ABS by that Recommendation for redio astronomyand by the coordination agreement for the National Radio Astronomy Observatory (NRAC) (includes the National Radio Quiet Zone (NRQZ) ste at Green Bank, WV),and National Astronomy and Tonospere Center (NAIC) sites.

ewsarzens aaina res—aoo—oon« asteonow prvicion mee n ExECUTION cory There are two frequency ranges thatrequire protection, 14.0— 14.05 GHz (NASA) and 14.47 — 14.5 GHz (NSP). By inspection ofFigure 1 it is clear tht frequencies supported by transponders 1,2, 23, 24 fall within the protected ranges. The next step is to determine how much attenuation can be achieved by frequency separation. Figure 2 shows the spectral mesk imposed by Section 25.202() ofthe FCC rules. ‘The actual performance ofthe ViaSat AES is considerably better than this mask. Figure 3 shows a measured spectrum plot ofthe ViaSat AMSS terminal‘s GMSK modulation ‘measured at the output ofthe power amplifier and the Section 25.202(D spectral mask. Tnspection ofthe spectrum in figure 3 shows that 36 MHe away from the center frequeney, the power spectral densityis down 55 dB and beyond 40 MHz is generally65 dB below the specified PSD. § By inspection ofthe trnsponder plotin Figure 1 and the spectzal output ofthe modem in Figure 3, we can determine to what degree frequencies in addition to the above need to be considered in the protectionstrategy. In addition to transponders 1,2, 23, and 24, transponder 22 is precluded from use during periods of radio astronomy observations — andtransponder 3, portions ofwhich fall within the 14.0—14.05 GHz band used by NASA at the other end ofthe spectrum, must be avoided as well The key finding is that only transponders 21 and those at lower frequencies are practical for AMSS service with some additional attentation necessary during periods ofadio astronomy observations. * e | —A— P I1 BM w f 1 = cretmsne Figure 2 BCC 2502( Tranoponder Spectral Mask

ewazrzons saiss res—ass—sese astennow pivtston mroe ae EXECUTION CorY [ & I: i 4 s a a r Anvestsrns en on tenorat Figure 4 Maximum Permitted PFD from a SogleAES Terminal Annex 2 to TTU—R M.1643 provides a method for defining a lower hemisphere EIRP mask from a power flux density (pR) mask. Given the altifude ofthe aircraf and the angle below the horizontalofhe radio signal departing from the ABS, the angle of artival ofthe radio signal at the Earth is determined along with the spreading loss from the ABS to the considered point on the Earth‘s surfice. "The resultent mask gives the maximum allowed EIRP density forthe specified pmask. Figure 5 shows the resultant radio astronomy masks for several ABS altitudes and the NRQZ and VLBA masks for 5,000 A.

cu/2re00s reiss resease—sese setrorow pivistou mee un ExEcurion cory nnene mosimnnnemien a : & #0% ¥0% hage on tofomous ces Fipure S EIRP Denaty Mask per 15 kB fr Various Aldtaden With the emission limits established, he nextsteps are to derive and plot the ABS EIRP density as function ofangle below the horizontal and compare the results t the mask and to the NSF site protection requirements. The first step in that process is to compute the EIRP density in the main lobe of the ABS at boresight. Using data from the linke budget fora typical AES terminal operating at 128 kbit‘ in CONUS, the BIRP is 31.3 dBW. The occupied bandwidth is 30.346 MHz, so the EIRP density is —43.52 dB(W/Hz), or $.24 dBOW/150 kHz) —the reference bandwidth used in ITU—R M.1643 Annex 1 Part 6. j Having determined that the boresight EIRP density for the AES terminal is 8.24 dB(W/1 50 kHz), the nextstep is to apply the antenna gain as a function ofelevation angle relative t the main lobe to determine a lower hemisphere EIRP density. When operating on the AMC—6 spacecraft, the lowest operating elevation angle for CONUSis 15.4, when operatingin the Seatte, WA area. The pointing angle with respect to the satelite remains constant, regardless of changes in airraftatttude. The mechanical lower imit for antertia pointing is 6 degrees and if due to aireraft maneuvers, he antenns can not emein pointed at he satelite, the trnsmitter will be inhibited. The only effect ofairereft meneuvers therefore is to the change the effective masking of the signal by the aiframe. For t purposes ofthis plan, airftame masking is estimated to be 10 dB.

ea/azrases sns res—nss—sen sstronow prviston reee az EXECUTION COPY Figure 6 depicts the relative E—Plane (elevation) ofF—axis gain ofthe ViaSat AMSS antenna compared to he boresight gain. Also shown in figure 6 is a relative antenna gain mask used for calculation purposes in this plan. Tt shows a —30 dB floorfor relative gain for offaxis angles greater thin 26.5. Next this relative antenna gain mask is combined with the 8.24 dB(W/150 kHz) AS EIRP density and the 65 dB ofout ofband attenation and then overlaid on the Radio . Astronomy mask in Figure 7. We see that with this antenna pattem the NRQZ and 1 VLBA sitesare protected for all angles ofarrival as long as the ABS is above 5000 ft sa9 098 crmmnpren Figare 6 Reatve OffAnis Giln

sarrz/zoas raiss es—zsr—sese astmovon orviston mee as EXECUTION COPY tz pentyant es n coqurit ty ho ren nrncamrgen Figure 7 ARS EIR® Denaly and RA Masks Assuming a 65 dB out ofband attenuation value, a lower hemisphere elevation antenna pattern mask as good as, obetter than the one used in figure 6 would be required to support unrestreted operation on transponders 4—21 down to 30,000 feet atangles of arival of65° orhigher. 3 This is consistent with ITU—R Recommendation M.1643, which states that AMSS carth stations should not transmit in the 14.47—14.5 GHz band within line—osight of adio astronomy stations operating within this band. 1 The data presented thus for has been limited to a single AES terminal operating at a nominal EIRP for a 128 kbit‘s data transmission. The ViaSat AMSS network will be comprised ofmany airereft each equipped with a technicallyidentical ViaSat AMSS terminal. All ABS terminals operate under control ofthe Network Management System (NMS) located at the Network Operations Center (NOC). The NMS software manages the multiple user aspects ofthe system. Each AES terminal operates in a continuous receive, burst transmit mode. The terminal only tramsmits when the user has dat to send, i.., mouse clicks, URL address requests, emails, and so on. Additionally, the terminal willrespond to periodic pollsfor satus from the NMS. Network statstis indicate that the majority of the time the ABS terminal is quiet and not transmittng.

perrzrzons raise res—ass—sese «strovow prviston mice i« EXECUTION COPY The link budget data shows that the number ofsimultaneous transmiters forthis network is 34, The network itsclfis designed to accommodate a large number oflogged in users, most ofwhich ar not transmitting at any given time. The NMS manages Network capacity by monitoring the number ofsimultencous transmissions and applying "throttling" commands o the terminalsin the network if the average number of simultancous transmissions reaches a configured limit Given the spetial separation of he AES terminals in the network and the fact that the terminal does not transmit unless there is user data to send, the likeihood of a significant i number of ABS terminals transmiting at the same time while in the vicinity of a RA site is low. Masinam PFD rom a vattats $ 09 00 Cg e h0 s es pgratzoms Figure 8 Meximun AES PFD ate Seleted Alltudes v. Angleof Arrival Figure 8 shows the PFD from a single AES operating at various altitades. This figure includes the 65 dB ofout ofband artenation and 10 4B ofairframe shielding. When operating at a fight level of 30,000 ft there is 17.7 dB ofmargin above the NRQZ ageregate PFD limit. Even ifall 34 aircraft were above a NRQZ site and transmitd simultancously (from above, 34 is the maximum number ofaireraftin the network allowed to transmit simultneously by the NMS) there would stllbe 17.7— 10 * logB4) =2.38 dB ofmargin in meeting the ageregate PFD limit. "This is a pathological case as Internet usage statstics suggest a ratio in the 30:1 range for a less than 1% chence that users would request data at the same ime, .., out of 300 users, less then 10 would likely request data atthe same time.

earzzrzons roiss res—ass—sese astronom prviston mee as EXECUTION COPY The ViaSat AMSS ABS terminals are programmed with the locations of the protected sites and equipped with algorithms that determine when an AES must cease transmission while operating in te vicinity ofa protected site. ViaSt will monitor network operations and update the ABS operating parameters periodically asrequired to ensure that ABS terminalsinhibit theirtransmissions asrequired to adequatelyprotect NSP sites during periods of scheduled observations. Method Three — Geographical Avoidance The final protection method is geographical avoidance. As previously noted, TTU—R M.1643 and subsequently the FCC, requires that the SFD masks for both types of radioastronomy sitesare met. As determind above, the AES must inhibit transmission within line—ofsite ofany RA site during periods ofrdio astronomy observations. To ensure thatthisrequirement is met the AMSS system operator must be notified ofwhich sites will be nctive and at what times, The AMSS operator must then load this information into the Network Management System so that it can be broadcast to all active aireraft The aireraft will then be required to nhibit transmissions by transponders 21—24 while within ine of sight ofthaffected observatory . ‘ViaSat will make the locations and schedules of radio astronomy stes available toits customers so they may modify flight paths ifthey choose, to avoid the coordination zone and thereby avoid loss of Internet communications during the fight Finall, the location ofeach aireraft equipped with the AMSS system is logged ‘hroughout their fight. This data is maintainedat ViaSt and can be used to help determine if an aireraft was near a ste when interference by inSat was suspected. This data will be reviewed periodicallyto produce such statisticsas the closest aircraft approsch to a protected sit, ircraft heading, minimum altitude over the ste, and maximum number ofaireraft simultzncousty within the protection zone for th site.


Document Created: 2006-11-22 12:36:45
Document Modified: 2006-11-22 12:36:45
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