1、 - - STD-ITU-R RECMN S.1253-ENGL 1997 4855232 0530352 T73 Rec. ITU-R S.1253 1 RECOMMENDATION ITU-R S.1253 TECHNICAL OPTIONS TO FACILITATE COORDINATION OF FIXED-SATELLITE SERVICE NETWORKS IN CERTAIN ORBITAL ARC SEGMENTS AND FREQUENCY BANDS (Question IT-R 23014) (1 997) The ITU Radiocommunication Asse
2、mbly, considering a) that the IT-R has been studying the efficient use of the geostationary-satellite orbit (GSO) for many years; b) that the IT-R has adopted a number of Recommendations to promote the efficient use of the GSO; c) that in some coordination circumstances, especially in some regions o
3、f the orbital arc and in some frequency bands, it may be necessary to empioy technical criteria additional to currently recommended criteria in order to complete a successful satellite coordination; 4 that in some coordination circumstances it may be necessary to employ new technical constraints in
4、order to achieve a successful satellite coordination; e) that it may be appropriate to apply different technical constraints in different orbital arc segments and frequency bands based upon the degree of use and type of application; f) the large number of Appendix 4 to the Radio Regulations submissi
5、ons to the Radiocommunication Bureau in all satellite bands below 30 GHz, recommends 1 that administrations be cooperative in employing the technical constraints contained in the ITU-RRecom- mendations pertaining to satellite and earth station parameters as a minimum in all segments of the orbital a
6、rc; 2 that, in those regions of the orbital arc, and in those frequency bands where difficulty has been experienced, administrations should employ additional technical criteria to the extent practicable in order to facilitate coordination; 3 that administrations should propose new IT-R Recommendatio
7、ns or modifications to existing ITU-R Recom- mendations for technical constraints appropriate for certain orbital arc segments and frequency bands where coordination difficulty has been experienced; 4 that administrations should specifj in which orbital segment the proposed new or additional technic
8、al criteria should be applied. NOTE 1 - Administrations are urged to provide IT-R with information on difficulties experienced in the coordination of satellite networks, particularly where perceived “excessive protection margins” and time delays have occurred. NOTE 2 - It is recognized that an opera
9、tional factor is sometimes used to help in solving coordination difficulties in some frequency bands and orbital arcs. For example, operational arrangements are sometimes reached based upon limited term operational plans. This type of arrangement is reviewed and revised in case of changes to the operationalhechnical assumptions.
