1、 Recommendation ITU-R F.758-6 (09/2015) System parameters and considerations in the development of criteria for sharing or compatibility between digital fixed wireless systems in the fixed service and systems in other services and other sources of interference F Series Fixed service ii Rec. ITU-R F.
2、758-6 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which R
3、ecommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is describe
4、d in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of
5、 the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for te
6、levision BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF F
7、requency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure deta
8、iled in Resolution ITU-R 1. Electronic Publication Geneva, 2015 ITU 2015 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R F.758-6 1 RECOMMENDATION ITU-R F.758-6* System parameters and considerations in the deve
9、lopment of criteria for sharing or compatibility between digital fixed wireless systems in the fixed service and systems in other services and other sources of interference (Question ITU-R 252/5) (1992-1997-2000-2003-2005-2012-2015) Scope This Recommendation contains principles for the development o
10、f sharing criteria of digital systems in the fixed service. Considerations are mainly given on how to properly design performance and availability degradations due to interference within the allowable objectives, as specified in Recommendation ITU-R F.1094, under the various interference environment
11、s. It also contains information on representative technical characteristics and typical system sharing parameters of digital fixed wireless systems in the fixed service for use in sharing studies above about 30 MHz. In cases where analyses indicate sharing issues, additional information on specific
12、fixed systems deployed by administrations can be found in Report ITU-R F.2108. Keywords Fixed service, sharing criteria, compatibility The ITU Radiocommunication Assembly, considering a) that it is necessary to establish sharing criteria between the fixed service (FS) and other services in frequency
13、 bands where both services are allocated with equal rights; b) that sharing may be managed by determining allowable values of performance and availability degradations of fixed wireless systems (FWS) caused by interference from other radio services allocated in the same frequency bands as the FS wit
14、h equal rights; c) that compatibility with systems of other services having allocation in the same band on a secondary basis, unwanted emissions from any other systems of services outside the band under consideration, falling into a band allocated to the fixed service on a primary basis, and emissio
15、ns from sources other than radio services need also to be taken into account; d) that principles for apportioning the performance and availability degradation among the different elements of the FWS and between each interference source, need to be established; e) that the technical characteristics o
16、f each service need to be understood in order to derive interference criteria corresponding to the allowable degradation in performance and availability of the FWS; f) that performance and availability degradation may result from both long-term and short-term interference and hence both long-term an
17、d short-term interference criteria need to be established; * This Recommendation should be brought to the attention of Radiocommunication Study Groups 4, 6 and 7. 2 Rec. ITU-R F.758-6 g) that availability of a basic methodology for the development of sharing criteria for the FS is useful for other I
18、TU-R Study Groups, noting a) that characteristics of digital and analogue fixed systems based on previous versions of the Recommendation are contained in Report ITU-R F.2108; b) that Recommendation ITU-R F.1094 provides the overall apportionment principle of the performance and availability degradat
19、ions to the FS due to interference from other services or sources, recommends 1 that the development of sharing criteria and assessment of interference conditions between the FS and other services and other sources of interference should be considered in accordance with the principles described in A
20、nnex 1; 2 that the information provided in Annex 2 should be considered as guidance to the technical characteristics and typical system parameters of digital fixed wireless FS systems that need to be taken into account when developing criteria for sharing with other services; 3 that the system param
21、eters in the tables in Annex 3 may be used as supplementary information for the bands for which Annex 2 does not provide typical parameters. Annex 1 Basic considerations in the development of sharing criteria 1 Overall performance objective One of the functions of a radiocommunication planner is to
22、design and implement a transmission network which meets the performance objectives laid down by the ITU-T and ITU-R. It is important, therefore, that real systems can meet the appropriate design objectives, recognizing the increasing use of the radio spectrum. There are various ITU-R F-Series Recomm
23、endations that relate to the overall performance objective for various types of circuit. 1.1 Error performance and availability objectives 1.1.1 ITU-T and ITU-R Reference Recommendation Error performance objectives for real digital fixed wireless links used in 27 500 km hypothetical reference paths
24、and connections are given in Recommendation ITU-R F.1668, Error performance objectives for real digital fixed wireless links used in 27 500 km hypothetical reference paths and connections, based on Recommendations ITU-T G.826, ITU-T G.828 and ITU-T G.829. It is the only Recommendation defining error
25、 performance objectives for all real digital fixed wireless links. NOTE 1 The applicability of older Recommendations ITU-R F.634, ITU-R F.696 and ITU-R F.697 is limited to systems designed prior to the approval of Recommendation ITU-T G.826 (December 2002). Availability objectives for real digital f
26、ixed wireless links used in 27 500 km hypothetical reference paths and connections are given in Recommendation ITU-R F.1703, based on Recommendation ITU-T G.827. It is the only Recommendation defining availability objectives for all real digital fixed wireless links. Rec. ITU-R F.758-6 3 NOTE 2 The
27、applicability of older Recommendations ITU-R F.695, ITU-R F.696 and ITU-R F.697 is limited to systems designed prior to the approval of Recommendation ITU-R F.1703 (January 2005). Most new applications are for systems using a single or a small number of hops (for example, for cellular network backha
28、ul or for connecting remote areas to metropolitan area networks). Nevertheless, the interference protection of each hop continues to be based on the Recommendations cited above. 1.1.2 Time basis for evaluation 1.1.2.1 General principles Availability evaluation is made on a time basis of one year, as
29、 established by ITU-T (G.827) and is independent from the actual transport media. Error performance evaluation is made on a time basis of one month, as established by ITU-T (G.826) and is independent from the actual transport media. In particular, since radio propagation is characterized by large va
30、riability depending on season and climate, the objectives are intended to be fulfilled in the worst month (which concept is clarified in Recommendation ITU-R P.581). When necessary, for prediction purposes, conversion of annual statistics to worst-month statistics is addressed in Recommendation ITU-
31、R P.841. In case of radio connections affected by interference from any source, the overall error performance and availability evaluations include the additional effect of interference within the appropriate time basis above. It should be noted that the concepts of “long-term” and “short-term” inter
32、ference (see 4.1 and 4.2 in this Annex 1) are not directly correlated with the “month” or “year” time basis. Both types of interference, depending on their time and level variability, may, in principle, affect the “error performance” (on month basis), but only interference longer than 10 consecutive
33、 seconds may affect the “availability” (on year basis) of FS systems. The latter will normally only be seen in long-term interference, but in special cases may include short-term interference. 1.1.2.2 Practical applications According to the principles described above, whenever a sharing or compatibi
34、lity situation with FS systems arises, different studies are necessary for separately evaluating the impact of the interference on FS availability (on year basis) and FS error performance (on month basis). However, in some practical cases, both studies are not necessary due to the expected physical
35、situation of the wanted and unwanted paths. In particular, when the interference into FS victim is constantly present (e.g. from a GSO space station), it is generally assumed that the acceptable level of interference should be sufficiently low for not affecting the FS system availability threshold,
36、on a yearly basis. In this case, ensuring the suitable FS availability degradation, it is generally assumed that any related “error performance” degradation would be within the acceptable limits (in any month) and no specific study is required. On the contrary, when the interference into the FS vict
37、im is relatively fast varying (e.g. from a non-GSO space station), it is generally assumed that, due to uncorrelated wanted and unwanted paths, the acceptable interference level may be higher, so that the “error performance” degradation would predominate over the possible “availability” degradation.
38、 In this case, the “error performance” degradation study should be carried out on the “worst month” basis (see example in Recommendations ITU-R F.1108 and ITU-R F.1495). 4 Rec. ITU-R F.758-6 In principle, it is expected that, when the variability of the interference is slowing down (quasi static sit
39、uations), there might be a speed threshold where both “availability” and “error performance” degradations might be equally impacted. In such cases, specific studies should be carried out for both cases with their appropriate time basis. 2 Sub-division of the performance and availability objectives T
40、he previous section dealt with the overall performance objectives for digital reference connections. However, there are, in practice, a large number of potential sources of interference contributing to the degradation of performance of a fixed wireless system. In order to move towards a practical me
41、thod for planning, the overall performance objectives need to be subdivided between individual sections of the overall hypothetical reference connections (HRX) and hypothetical reference path (HRP). Within a section, the performance objective is then apportioned between the various sources. 2.1 Appo
42、rtionment of section error performance and availability objective This is covered in Recommendation ITU-R F.1094, Maximum allowable error performance and availability degradations to digital fixed wireless systems arising from radio interference from emissions and radiations from other sources. The
43、allowable performance objective is divided into an element of X% for the FS portion, Y% for frequency sharing on a primary basis, and Z% for all other sources of interference (it should be noted that X% + Y% + Z% = 100%) where X, Y, and Z are typically 89%, 10%, and 1%, respectively. There may be a
44、further subdivision of the X% allowance to suit local requirements and this could be apportioned in such a way as to suit the grade of service (see 4.1.3). A particular point to note is that an interference source (say a transmitter Tx) may affect more than one hop of a system. 2.2 Apportionment of
45、performance and availability degradation to different services When establishing the sharing criteria with other co-primary services, it may be necessary to consider the apportionment of the error performance objective (EPO) and availability performance objectives (APO) to short-term and long-term i
46、nterferences (see the introductory part in 4). Then, the following points should be taken into consideration: a) For the band shared by the FS and one radio service on a primary basis, performance/availability degradation Y1% of the FS caused by the interference from other services should not exceed
47、 10% of the objective in accordance with Recommendation ITU-R F.1094. b) After the establishment of the sharing criteria with the first co-primary service, performance/availability degradation Y2% of the FS caused by the interference from another co-primary service sharing the same band may be devel
48、oped as follows: multi-interference environment due to both services should carefully be examined, in particular the case leading to the allowance limit of Y1% and simultaneously receiving additional interference from the second co-primary service; then the limit of Y2 could be derived from a typica
49、l interference model for the FS and the second co-primary service taking also into account potential effect of the first co-primary service in that model. Rec. ITU-R F.758-6 5 3 Characteristics of interference It is necessary to have information available on interference levels arising from other services, which would degrade system performance by specific amounts. This would be facilitated if, with the assistance from other Study Groups, a table were compiled giving information on the characteristics of emissions. Two categories of interference are worth considering: for s
