By Norman Weinhouse, Hughes Communication, Inc.
The Federal Communication Commission "Open Skies" policy, which allowed technically and financially qualified entities to launch and operate domestic satellite facilities, has been a great success. Benefits to virtually all elements of the telecommunications industry and ultimately to the public have been derived. The policy has certainly been a positive factor in the CATV industry, and perhaps a major technological catalyst in its development.
The geostationary orbital arc, that imaginary line 22,300 miles above the earth's equator, is a finite resource. It has been 2-1/2 years since the Commission made its last C-band authorization!. That round of authorizations established a constellation of C-band satellites with 4° spacing. Most of those satellites are currently in orbit, some will be launched this year, and the balance next year. The applications kept coming to the Commission, and in November 1981 a Notice of Inquiry and Proposed Rulemaking was issued relating to the implementation of a 2° spacing plan for both C-band and Ku-band satellites. The rulemaking involved establishment of new technical standards for earth station antennas relating to the gain and cross polarization isolation in the close-in sidelobes. Comments were made by 37 entities. At last year's NCTA convention this author was moderator of a session on this subject and gave a detailed report on the comments received by the Commission. At the time this paper is written, the FCC has still not completed its deliberations in this docket. Regardless of the exact determination, CATV existing facilities will be adversely affected. The degree to which they will be affected and when this will take place is speculative, and any analysis ultimately involves a subjective evaluation of an acceptable level of interference.
This paper will outline the ground terminal receive only design considerations 156 for 2° spacing of C-band satellites to permit antenna manufacturers to assess and respond to the changing marketplace. By the same token, operators should be aware that their facilities will probably need to be upgraded.