Attachment ex parte

This document pretains to SAT-AMD-20031118-00332 for Amended Filing on a Satellite Space Stations filing.

IBFS_SATAMD2003111800332_415601

C371 377 HO SIHYI X3 toeG,tern Yex Bevdon Mobile Satelite Ventures io EX PARTE OR LATE FILED moue: ressam Re MRD is Ievogminncen PuBLIC coRY January7, 2005 ORIGINAL Via Hand Delivery Ms. Marlene H. Dortch, Secreuary RECEIVED Federal Communications Commission 445 12th Street, S.W. JAN =7 2005 Washington, D.C. 20554 FotealCam reniatentrmnisten Re: Mobile Satellite Ventures Subsidiary LLC Ex Parte Presentation 1B Docket No. O1—185 File No. SAT—MOD—20031118—00333 (ATC application) File No. SAT—AMD—20031118—00332 (ATC application) File No. SES—MOD—20031118—01879 (ATC application) Dear Ms. Dortch Mobile Satellite Ventures Subsidiary LLC (‘MSV")herebyfiles the attached study demonstrating a technique fofurther reducing the potential nterference to adjacent—channel mobile terminals in airportsand on waterways while relaxing the imits on ATC base station power flux density. MSV has redacted Figures 1, 2, and 3 from the attached study because they contain information relating to the ongoing international L—band frequency coordination process which is confidentil among the parties to that coordination. ‘The Commission has acknowledged the confidentiality oinformation relating tothis coordination process." MSV has served a non— redacted copy ofthis study on Inmarsat Ventures L., which is also a party to the L—band coordination Please direct any questions regarding this matter to the undersigned. Very truly yours, L. Cé. taxsese «AlZ. Lon C. Levin ! Comsat Corporation, et al. File No. ITC—97—222, FCC 01—272, Memorandum Opinion, Order and Authorization, m 48 106—107 (Oct. 9, 2001).

Jan 05 2005 eroten momile srtelcite ventures 7osa002770 cexmEication 1, De, Peter D. Karubinis, Vice President& ChiefTechnieal Oficer ofMobile Satllte Ventures Subsidiry LLC (‘MSV"),certfy under penalty ofperjry that: 1 am thetechnically qualified person with overal responsibility forpreparation ofthe information contained in th foregoing. I am familine with the requirements of the Commission‘s mles, and theinformation contained in soing is true and correst. Exceupld on January 5, 2005 ZPeter D. Kerabini Vice President & Chief Technical Officer

ces Donald Abelion Jim Ball William Bell Richard Engelman Chip Fleming Howard Gboft Karl Kensinger Pasl Locke Kathym Medtey Robert Nelson Sean O‘More Roderick Porter Steve Spach David Strickdand Cassandra Thomas Thomas Tyce Jobe Janka, Counse for Innarsat

Consequently, subject to an MSV ATC base station deployment that. over all sectors facing and serving navigable waterways, adheres to the constraints of Figure 38 dB of relaxation in the PFD limits estblished by the Commission in the ATC Order (and later corrected by MSV)° is appropriate while continuing to protect Inmarsattrminals that are operating in navigable waterways against harmful overload interference. Thus, the Commission can establish additional flexiblity in PFD limits or safe harbor distances for airports and navigable waterways subject to the specific ATC base station deployment constraints presented above. The additional flexibility in PFD limits or safe harbor distances will offer MSV additional flexibility to deploy ts hybrid satellte/ATC network, in certain areas, with less capital expenditure while adequately protecting Inmarsat terminals against harmful overload interference. ‘The Commission may thus suthorize MSV with the flexibility to () offer ATC service near airports and navigable waterways subject o the constrained deployment offrequencies as described above, with 8 dB of additional flexiblity in PFD limits ocorrespondling reductions in safe harbor distances, or (1)offer ATC service near airports and navigable waterways without any constraints in carrier deployment while stisfying the stricter PFD limits or safe harbor distances that have already been established by the Commission. ° See MSV ATC Application at21—22; see also MSV Ex Parteltter, IB Docket No. 01— 185 (November 18, 2003).

Additional Protection for Terminals Operating in Open Areas of Airports and Navigable Waterways ATC base station emissions that are aimed toward a harbor/navigable waterway or an airport may potentilly overload sateliteterminal receivers thatare operating in such areas. Based on this conclusion,the Commission established PFD limits and safe harbor distances that, when adhered to by ATC base station deployment, protect land» transportable, AMS(R}S and GMDSS terminals." An overioad conition may produce Inter—Modulation (IM) products within a receiver‘s front—end that may fall within the receiver‘s operating frequencies. MSV has found that near airports and navigable waterways, the potential for any harmful TM interference may be further reduced by constraining ATC base station deployments to radiate anly specific subsets ofMSV‘s frequencies. Base station sectors that are facing toward an airport or a navigable waterway may be constrained to radiate only two orthree carrir frequencies, judiciously chosen from MSV‘s ensemble offrequencies, such that the third—order IM products do not impact major portions ofInmarsat‘s spectrum. Specifically, it has been found that limiting the number ofcarer frequencies that may be deployed by ATC base sation sectors facing and serving navigable waterways or airports to no more than three,will protect major portions ofInmarsat‘s seronautical and maritime spectrum to a much greater extent than a deployment that uses all available frequencies. As such, a limited number ofcarier frequencies (up tothree) may be radiated athigher power levels. Puttingit differently, subject tothe constrained deployment methodology described herein below, the Power Flux Density (PFD) limitsforairports and navigable waterways and/or the separation distances established by the commission may be relaxed. Specification of constrained deployment and measurements: Figure 1 depicts the current allocation ofMSV and Inmarsat spectrum. In accordance with the selection criteria described above,three 1.25 MHz edma2000 (1XRIT) carriers are identiied in Figure 1 for ATC deployment near nirports and navigable waterways." Given the location of Inmarsat acronautical and maritime spectrum,it has been found by laboratory measurements that utlization ofthe carier frequenciesidentified in Figure 1 optimally protects Inmarsat terminals that may be communicating from within airport open spaces or from maritime vessels in proximity to the shore. ‘ See ATC Order, Appendix C2 at219. * The approach also works with any other ai interface protoool.

established by the Commission in the ATC Order (and later corrected by MSV)is appropriate while continuing to protect Inmarsat terminals thatare operating in airport open spaces (using upper L—band spectrum‘) against harmful overlond interference. Figure 3 — GAN Terminal Overload Threshold for 3 CDMA Interfering Carriers REDACTED Constrained deployment near navigable waterways: From Figure 3 we observe that by limiting MSV‘s deployment near navigable waterways to only three carriers, as is assumed in Figure 3, a GAN terminal operating over Inmarsat‘s manitime spectrum (at any frequency lower than 1540 MHz) would experience overload ata received interference level of—56 dBm (while operating at edge—0f—coverage and without the aid of power control or at —52 dBm ifit operated under more favorable link conditions of 6 dB more desired signal power (as would be provided by power control and/or by a more favorable geographic location), As stated carlier, these overload thresholds (of—56 dBm and —52 dBm) are 4 dB and 8 dB grester, respectively,relative to the —60 dBm overload threshold that was assumed by the Commission in the ATC Order. The Inmarsat GAN family of terminals (as well as all other modem Inmarsat equipment including R—BGAN, BGAN, Mini—M, M, and B terminals) is designed with power control capabiliy. ! See MSV ATC Application at 21—22; see also MSV Ex Parteltte, IB Docket No. 01— 185 (November 18, 2003). * Note that if a termina is operating using lower L—band spectrum, the protection is significantly greater, as can be seen from Figure 2.

Figure 1 — Current Region 2 Spectrum Allocations for MSV and Inmarsat REDACTED Figures 2 and 3 below summarize laboratory measurements of overload threshold as a function offorward—link operating frequency ofa satelliteterminal. The satelite terminal is an Inmarsat GAN terminal.\ The power level at which overload occurs is referenced to the terminal‘s antenna output port (inputto the terminal‘sfront—end electronics) and the overload threshold is defined by the Bit Error Rate (BERthreshold of 10. Figure 2 presents resultsfor the case where the two lowest MSV carriersidentified in Figure 1 are deployed. Figure 3 presents resultsfor the case where allthree MSV carriers identified in Figure 1 are deployed. Measurements were conducted at two levels of satellite terminal forward—link carvier: 1) A "basline" evel corresponding to a nominal edge—0f.coverage forward—link carrier EIRP, and 2) A higher forward—link carrier level (+6 dB relative to baseline)to simulate the effect of additional power being delivered t the satelite terminal (as may be the case when the satelite terminal is operating in a more favorable geographic position andr is receiving more power via power control). Also, two configurations of CDMA carrier power levels were evaluated: A) All interference carriers used are ofequal power (solid lines), and B) One interference carrir (out ofthe two or tiree)having 6 dB more power than the other(s) (dashed lines) * The measurements were conducted at MSV‘s facilies. MSV has procured and used the same Inmarsat system emulation tools that the Commission has used to perform messurements of overload.

The Figures plot received power at satelit terminal‘s antenna output port (input tothe terminal‘s front—end electronics) vs. forward—link frequency ofoperation of the satelite terminal. Figure 2 — GAN Terminal Overioad Threshold for 2 CDMA Interfering Carriers REDACTED Constrained deployment near airports: Itis interesting to observe from Figure 2 above that by limiting MSV‘s deployment near airports to only two carries, as is assumed in Figure 2, a GAN terminal operating over the portion of Inmarsat‘s aeronautical spectrum at a frequency lower than about 1547 MHz would experience overload at a received interference level of —56 dBm (while operating at edge—0f.coverage and without the aid ofpower control) or at —52 dBm if t‘s operating under more favorable link conditions of6 dB more power (as would be provided by power contral and/or a more favorable geographic location}. The overload levels of—56 dBm and —52 dBm are 4 dB and 8 dB greater, respectively,reative to the 60 dBm overload threshold that was assumed by the Commission in the A7C Order. The Inmarsat GAN family of terminals (as well as all other modern Inmarsat equipment including R—BGAN, BGAN, Mini—M, and M terminals) is designed with power control capability. Consequently, subject t an MSV ATC base station deployment hat, over all sectors facing and serving airports, adheres to the constraints of Figure 2. 8 dB of relaxation in the PFD limits


Document Created: 2005-01-31 16:05:14
Document Modified: 2005-01-31 16:05:14
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