Attachment SUPPLEMENT

SUPPLEMENT

SUPPLEMENT

SUPPLEMENT

2004-08-25

This document pretains to SAT-MOD-20040212-00017 for Modification on a Satellite Space Stations filing.

IBFS_SATMOD2004021200017_397611

S a~ us ORIGINAL > mz > — August 20, 2004 D Via Hand Delivery P RECEIVE! Ms. Marlene H. Dortch Reoflived pe m HamCopmunienionCommision 82500 (sucpecengeme Secreiary k AUG Washington, D.C. 20554 C mpurees RE: XM Radio Inc. SAT—RPL—20040212—00019 (Call Sign S2617) (Application to Launch and Operate Replacement SDARS Satellite at 85°W) SAT—MOD—20040212—00017 (Call Sign $2118) (Minor Modification to Relocate SDARS Satellite from 85°W to 115°W) SAT—RPL—20040212—00018 (Call Sign S2616) (Application to Launch and Operate Replacement SDARSSatellite at 115°W) Dear Ms. Dortch: On February 12, 2004, XM Radio Inc. (XM Radio") filed the above—captioned applications to() to launch and operate a replacement satellite (XM—3"; Call Sign $2617) at 85°W (see File No. SAT—RPL—20040212—00019); (i) upon launch, testing, and successful operation of XM—3, to relocate its current in—orbit stellite at 85°W ("XM—Roll," Call Sign S2118) to the 115°W orbital location where it will be temporarily collocated with XM Radio‘s in—orbit satelliteatthat location (*XM—Rock," Call Sign S2119) (see File No. SAT—MOD— 20040212—00017);and (ii) to launch and operate a replacement satellite (°XM—4"; Call Sign S2616) at 115°W (see File No. SAT—RPL—20040212—00018). The Intemational Bureau (*Bureau") placed these applications on Public Notice on March 19, 2004. See Report No. SAT— 00202 (March 19, 2004). The applications were unopposed. XM Radio hereby supplements these applications with the following information: (1) In compliance with the Bureau‘s Public Norice released on June 16, 2004,! XM Radio attaches as Exhibit A hereto a two—degree spacing analysis forits proposed satellites. XM Radio notes thatthere are no authorized or proposed satellites using either S—band or X—band frequencies within two degrees of its proposed satelltes. XM Radio has accordingly performed this analysis using the technical characteristies of ts own satelltes. ‘ See Report No. SPB—207, DA—1708 (June 16, 2004).

Ms. Marlene H. Dortch August 20, 2004 Page2 (2) In compliance with a Bureau decision released on June 16, 2004, XM Radio attaches as Exhibit B an analysis demonstrating that ts X—band feeder link antennas will have 30 dB of eross—polarization isolation as required by Section 25.210() ofthe Commission‘s rules. 47 CER §252100. (3) XM Radio hereby clarifies thatit proposes to locate the satellites subject tothis application at the following orbital locations: * XM—Roll (Call Sign S2118) will be relocated to the 114.90°W orbital location. * XM3 (Call Sign S2617) will be located at the 85. 10°W orbital location * XM~4 (Call Sign S2616) will be located at the 115.00°W orbital location. Please contact the undersigned with any questions regarding this matter. Respectfully submited, xM RADIO NC. 5 tC Lon C. Levin Senior Vice President 1500 Eckington Place, NE Washington, DC 20002 (202) 380—4000 es Tom Tycz, FCC Stephen Duall, FCC Robert Nelson, FCC * See Letter from Thomas S. Tyez, FCC, to Brian Park, AfriSpace, Inc., DA 04—1719, File No. SAT—LOA—20040413—00082 (June 16, 2004).

Exhibit A Two—Degree Spacing Analysis XM Radio‘s feeder link earth station operates in X—band frequencies (7.025 — 7.075 GHz) for uplink and S—band (2332.5 — 2345.0 GHz) for telemetry. There are no satelites operating within 2 degrees o XM Radio‘s current or proposed satelltes at 85°W and 115°W using these frequencies. According to FCC guidelines, XM Radio provides below a two—degree spacing analysis using technical characteristics ofan XM Radio feeder link earth station and XM Radio satelites. Table 1 presents the relevant parameters. Figures 1 and 2 present the measured pattems. Table 1 — XM Feeder Link Earth Station Antenna Characteristics Transmit antenna gain (dB) s3 Sidelobe pattem 29—25log0 Sidelobe gaiat 2.2" Topocentrc 165 separation Delta gain Main—Side Tob(dB) 370 Receive antenna gain (dB) 428 Sidelobe pattem 32—25tog0 Sidelobe gain at 2.2" Topocentric 28 separation Delta gain Main—Side lobe (dB) 200

Figure 1 — Measured X—Band Antenna pattemn Figure 2 — Measured S—Band Antenna pattem

Carrier—to—Interference analysis is shown in following section: Uplink C/1= EIRP, — EIRP, + (G, — G.) where: EIRP, = transmit power of wanted carrier toward the wanted satellite, EIRP, = transmit power of interfering carrier toward the wanted satellit, G, = wanted satellite receive antenna gain in direction of wanted feeder link station, G = wanted satellite receive antenna gain in direction of interfering feeder link station, Calculated uplink CA is about 394B, welbelow the coordination threshold value. Down C/1= EIRP, — EIRP, + (G4— G.) where: EIRP, downlink power of wanted carrier toward the wanted earth station, EIRP, transmit power ofinterfering carrier toward the wanted carth station, G, anted earth station receive antenna gain in direction of wanted satellite, anted earth station receive antenna gain in direction of interfering satellte, Calculated downlink C is about 28 dB, well below the coordination threshold value.

Exhibit B Cross—Polarization Isolation of Feeder Links With reference to Figures 3, the XM Radio feeder link earth station, operating in X—band frequencies, complies with Commission requirement stated in Section 25.210() 47 C.F.R. § 25.210(0). Measured eross—polarization discrimination is at least 30B within the half—power beamwidth. Figure 3 — XM Feeder Link Earth Station — Measured Cross—Polarization Isolation

Teclnical Certification 1,Jeffrey S. Snyder, Senior Vice President, Space and Ground Systems, of XM Radio Inc., cerify under peoalty ofperjury tha: T am the technically qualiied person with overal responsibility for preparation of the technical information contained in the foregoing. T am familiar with the requirements of Part 25 of the Commission‘s rules, and th information contained in the application is se and comrectto the best of my knowledge and belief. Joftrey 8. Suyder Dated: August /7 2004


Document Created: 2004-09-28 12:01:01
Document Modified: 2004-09-28 12:01:01
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