1、Rec. ITU-R BO.1297 1RECOMMENDATION ITU-R BO.1297*PROTECTION RATIOS TO BE USED FOR PLANNING PURPOSES INTHE REVISION OF THE APPENDICES 30 (Orb-85) AND 30A (Orb-88)PLANS OF THE RADIO REGULATIONS IN REGIONS 1 AND 3(Question ITU-R 85/11)(1997)Rec. ITU-R BO.1297The ITU Radiocommunication Assembly,consider
2、inga) that Resolution 531 (WRC-95) of the World Radiocommunication Conference (Geneva, 1995) invites theITU-R to study the possibilities to improve the efficiency of the Appendices 30 (Orb-85) and 30A (Orb-88) of the RadioRegulations (RR) Plans by taking due account of the technological progress;b)
3、that WRC-95 has adopted in Recommendation 521 (WRC-95) overall aggregate protection ratios;c) that protection ratios are essential characteristics for the planning of the broadcasting-satellite service (BSS)and the associated feeder links;d) that the RR Appendices 30 (Orb-85) and 30A (Orb-88) Plans
4、have been developed by using values ofprotection ratio based on fixed frequency offsets of 19.18 MHz and analogue signals;e) that the existing RR Appendices 30 (Orb-85) and 30A (Orb-88) Regions 1 and 3 protection ratios are no longerappropriate due to technological improvements made in the BSS;f) th
5、at measured data in support of an improvement of the protection ratios are available,recommends1 the use of the aggregate protection ratio provided in Annex 1 below, for planning purposes in the revision ofRR Appendices 30 (Orb-85) and 30A (Orb-88) Plans in Regions 1 and 3.ANNEX 1Aggregate protectio
6、n ratios to be used for planning purposes in the revision ofRR Appendices 30 (Orb-85) and 30A (Orb-88) Plans in Regions 1 and 3_*The Administrations of Saudi Arabia, the Islamic Republic of Iran and Syria reserved their position on the acceptance ofthis Recommendation until such time as they know precisely what were the reasons for the reduction in the protection ratio from30 dB to 22 dB and who benefited from that reduction.Co-channelprotection ratio(dB)Adjacent channelprotection ratio(dB)Feeder link path 30 22Down link path 24 16Overall path 23 15
