Attachment SUPPLEMENT

SUPPLEMENT

SUPPLEMENT

SUPPLEMENT

2004-08-25

This document pretains to SAT-RPL-20040212-00018 for Replacement Application on a Satellite Space Stations filing.

IBFS_SATRPL2004021200018_397614

                                         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

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC