Attachment Letter

This document pretains to SES-MOD-20040301-00304 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2004030100304_369889

                                  STEPTO E &Jo I-I N S O N                        LIP

                                               A T T O R N E Y S AT    LAW




Philip Malet                                                                              1330 Connecticut Avenue. NW
202.429.6239                                                                               Washington, DC 20036-1795
pmalet@steptoe.com               2 1 i.iLLU                                                         Tel 202.429.3000
                                                                                                     Fax 202.429.3902
                                                            APR 1 6 2004                                   steptoe.com
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                                           D    w   E   m   L C~MUNIC~JWNS    COMM~~~OM
m IL4NDDELz~my&)nal~au                                      OFFICE OF THE SECRETARY

April 16,2004

Marlene H. Dortch
Federal Communications Commission
Office of the Secretary
445 12th Street, SW
Washington, DC 20554

Re:    The Boeing Company Application to Modify Blanket AMSS Earth Station Authorization
       Call Sign E000723; File No. SES-MOD-20040301-00304

Dear Ms. Dortch:

       The Boeing Company (“Boeing”), at the request of PanAmSat Corporation (“PanAmSat”),
hereby submits the following information for association with the above-referenced application.
PanAmSat has indicated to Boeing that, with this information, it has no objection to the Commission
granting this application and that no fbrther coordination with PanAmSat is required with respect to the
operations proposed therein.

       The process by which the Connexion by BoeingSM(“Connexion”) Aeronautical Mobile-Satellite
Service (“AMSS”) system protects Fixed-Satellite Service (“FSS”) operations is described in the
original Transmit-Receive Application, Technical Supplement at 34 - 38’ and the Reflector Antenna
Modification Application, Technical Appendix at 14 - 16;2as well as Boeing’s 30-Day Report at 2-15



          See Application of the Boeing Company for Blanket Authority to Operate up to Eight Hundred
Technically Identical Transmit and Receive Mobile Earth Stations Aboard Aircraft in the 11.7-12.2 and
14.0-14.5 GHz Frequency Bands, File No. SES-LIC-20001204-02300 (filed Dec. 4,2000, supplemented
Jan. 1 0,200 1) (“Transmit-ReceiveApplication”).

        See Application of the Boeing Company to Modify Blanket Authorization to Operate up to
Eight Hundred Technically Identical Transmit and Receive Mobile Earth Stations Aboard Aircraft in the
11.7-12.2 and 14.0-14.5 GHz Frequency Bands, File No. SES-MOD-20030522- 00639 (filed May 12,
2003) (“ReflectorAntenna Modijkation Application”).




            WASHI N G T O N      PHOENIX                LOS ANGELES           LONDON         BRUSSELS


Marlene H. Dortch
April 16,2004
Page 2


(Boeing AMSS System License Compliance Report -- Reflector Antenna Update). Boeing now
provides the following additional detail to elaborate further as to how the Boeing A M S S system
accounts for antenna gain changes resulting from variations in the relative orientation of its roughly
elliptical reflector antenna to the geostationary orbit (“GSO”) arc.

        The Boeing AMSS system is designed to protect FSS operations from harmful interference from
aircraft earth station (“AES”) transmissions in the 14.0-14.5 GHz band. To accomplish this, the Boeing
Network Operations Center (“NOC”) controls the aggregate off-axis e.i.r.p. towards the GSO arc of all
AESs operating on a given transponder to be less than or equal to that of a routinely processed very
small aperture terminal (“VSAT”), or the transponder’s coordinated limits, which ever is lower.

        The AES control algorithm used at the NOC accounts for variations in aggregate off-axis e.i.r.p.
caused by a wide range of factors. These include, inter alia, the effects of the relative orientation of the
AES antenna major axis with respect to the GSO arc due to variations in location and orientation of the
AES vis-&vis the adjacent satellites. As the angle between the major axis of the AES antenna and the
GSO arc changes with longitudinal differences between the AES and the serving satellite, as well as
with latitudinal differences along the same longitude (except the longitude of the serving satellite), the
effective beam width of the AES antenna along the GSO arc also changes and so the gain along the GSO
arc will change. For example, if the major axis of the AES antenna is aligned with the GSO arc, the
beamwidth of the AES antenna is at its minimum, and the antenna gain towards the adjacent satellite
would be at a minimum. As the relative angle between the AES antenna major axis and the GSO arc
increases, the effective beamwidth of the antenna broadens, and the gain towards the adjacent satellite
would increase.

         The AES control algorithm accounts for this variation using a gain model of the roughly
elliptical AES reflector antenna that is projected from the actual location of the AES onto the GSO arc,
based on the pointing direction (as described above, a function of the location of the AES and the
serving satellite) and orientation of the AES antenna. The orientation of this calculated antenna beam
matches the orientation of the actual antenna beam. In this way, the AES control algorithm necessarily
accounts for changes in antenna gain related to differences in the angle between the major axis of the
AES antenna and the GSO arc. As the relative angle between the AES antenna major axis and the GSO
arc increases, the calculated gain towards the adjacent satellite would also increase. This higher antenna
gain is taken into account by the algorithm as it calculates e.i.r.p. towards the GSO, and the power level
of the AES is decreased, as necessary, to ensure that the aggregate off-axis e.i.r.p. density is maintained
below the level for routinely processed VSATs.




        See Letter to Marlene H. Dortch dated Feb. 12,2004, Call Sign E000723, File No. SES-MOD-
200305 12- 00639 (“3O-Day Report”).


Marlene H. Dortch
April 16,2004
Page 3


      Any questions regarding this matter may be directed to the undersigned.

                                          Respectfully submitted,


                                          Philip L. Malet
                                          Carlos M. Nalda
                                          Counsel for The Boeing Company

cc:   Joseph Godles
      Counselfor PanAmSat Corporation



Document Created: 2004-04-22 10:32:43
Document Modified: 2004-04-22 10:32:43

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