1、 CCIR RECMN*744 92 m Y855212 0518897 198 m Rec. 744 277 RECOMMENDATION 744 ORBIT/SPECTRUM IMPROVEMENT MEASURES FOR SATELLITE NETWORKS HAVING MORE THAN ONE SERVICE IN ONE OR MORE FREQUENCY BANDS (Question Doc. 4/2)* (1992) The CCIR, considering that for economic and practical reasons there are increa
2、sing numbers of GSO satellites having multiple that each of the networks may require different types of coordination procedures; that the GSO orbital spacing of the multi-network and/or multi-band spacecraft will be determined by the that Annex 1 describes the difficulties associated with coordinati
3、ng such satellite networks; Recommendation No. 715 of WARC ORB-88 invited the CCIR to continue its technical studies pertaining to a networks in multiple services and/or using one or more frequency bands; b c) largest required orbital separation; d e multi-band and multi-service satellite systems, r
4、ecommends 1. that when multiple coordination procedures are necessary with respect to a single spacecraft, individual methods should be applied to utilize all the flexibility available with full recognition of the implementation process inherent in each procedure; 2. that the technical and operation
5、al constraints of existing coordinated networks and of those being coordinated should be fully taken into account; 3. that administrations should in a cooperative spirit, take account of the preferred orbit positions, ailocated frequency bands, and technical parameters of proposed satellite networks
6、, which could assist in accommodating a new multi-network and/or multi-band satellite system, taking into account the factors outlined in Annex 1. 1. Introduction Regulations. In addition, it describes the type of networks associated with the different methods. networks are used on the same satellit
7、e. In this Annex, 0 2 describes the coordination methods, the applicable allocations, and parts of the Radio Section 3 is an analysis of the potential problems which may be presented when combinations of different Section 4 derives observations based on one example of a multiple network satellite. S
8、ection 5 summarizes the findings about multi-service and multi-band satellites. * Resulting from the rearrangement of existing Questions. CCIR RECMN*744 92 4855232 0518898 024 Improved procedures meeting) (Multilateral planning 278 Rec. 744 Certain FSS bands 2. Description of the situation for netwo
9、rks with more than one service in one or more frequency bands The procedural approaches for coordination and notification of frequency assignments to geostationary- satellite networks are indicated in Table I along with their distinguishing characteristics. As indicated below, there are multiple com
10、binations of frequency bands that can be put on a single satellite platform. When this occurs, multiple coordination procedures are necessary. A single band of a satellite may also be subject to multiple coordination procedures. An example of this is the 12 GHz FSS band in which a network may be sim
11、ultaneously subject to the procedures of RR Articles Il, 14, 15 and even Resolution No. 33. The coordination network possibilities are described below. TABLE 1 Method I Allocation (GHz) BSS Plan (SAT-77) Feeder links (ORB-88) BSS 11.7-12.5 (Region 1) BSS 11.7-12.2 (Region 3) FSS 14514.8 (Regions 1 o
12、rbit positioiis and operating parameters are defined by the Plans and in practice there is little flexibility in modification of orbital position short of seeking a formal plan change; there is only limited flexibility in equipment parameters choice. CCIR RECMN*744 92 4855212 0538899 TbO 5 3 Rec. 74
13、4 279 4 2.3 Allobnent plan networks 1 Those networks use spectrum which is part of the fured sateliite allotment plan (Appendix 30B of RR); the degrees of freedom will be limited by regulation. There may be some orbit position flexibility possible through use of the predetermined arc (PDA) mechanism
14、. However, this is dependent on the stage of development of the network. 2 5 2.4 Networks subject to multilateral planning meeting procedures These networks are those to which a multilateral planning meeting (MPM) applies. Coordination is based on RR Articles 11 and 13. The MPM will probably apply t
15、o congested orbital arcs where there will be little degree of freedom. 2.5 Unplanned band networks Networks in unplanned bands use the procedures in RR Articles 11 and 13. 3. Multiple coordination procedure pairs Satellite networks, in accordance with the categories described above which require mul
16、tiple coordinations, can be examined in pairs. The pairs of networks below correspond to the coordination procedure possibilities described in the sections above; i.e. 1 in Q 2.1,2 in Q 2.2, 3 in P 2.3,4 in 0 2.4, and 5 in Q 2.5. The basis for the pairing analyses may be explained by reference to Fi
17、g. 1. FIGURE 1 Satellite A and B coordination procedures Satellite A Satellite B Satellite A has frequencies that must be coordinated under procedures 1, 2 and 5. Satellite B has frequencies liable to procedures 5, 3 and 4. Networks in satellites A and B must coordinate with each other because they
18、are using the same, unplanned (5) fixed satellite spectrum. In addition, satellite A may also have to coordinate using procedures 1 and 2, and satellite B may also have to coordinate using procedures 3 and 4. Thus, the pairs below refer to the impact on coordination when one of the pair of procedure
19、s is on satellite A and the other is on B: 1 the constraints of coordinatedhegistered networks and of those being coordinated should be fully taken into account; administrations could in a cooperative spirit, take account of the desired orbit positions, frequency bands, and parameters of a proposed
20、satellite network, which could assist in accommodating a new multi-baridservice satellite; constraints imposed by the procedures can lead to difficulty in reducing interference levels for all services in a multi-service satellite. This was recognized for the fixed satellite service in Recommendation
21、 670. The recommended flexibility in relocation would facilitate the resolution of interference problems if it could be applied to all procedures and services. Additional technical information needs to be developed to illustrate the problems associated with such multiple coordination satellites particularly when one of the networks on the satellite has an orbit position fixed by a plan. - - -
