1、 Recommendation ITU-R S.2099-0 (12/2016) Allowable short-term error performance for a satellite hypothetical reference digital path S Series Fixed-satellite service ii Rec. ITU-R S.2099-0 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economica
2、l 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 Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by Worl
3、d and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described 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 fo
4、r 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 the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series
5、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 television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermina
6、tion, 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 Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satelli
7、te 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 detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2016 ITU 2016 All rights reserved. No part of this publicat
8、ion may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R S.2099-0 1 RECOMMENDATION ITU-R S.2099-0 Allowable short-term error performance for a satellite hypothetical reference digital path (Question ITU-R 277/4) (2016) Scope This Recommendation provides definitio
9、n on short-term in satellite communication systems, by considering up-to-date technical trend on satellite communication systems and standards, and specifies error performance objectives depending on the service and information. Keywords Error performance objectives, satellite hypothetical reference
10、 digital path, short-term Abbreviations/Glossary 3GPP 3rd generation partnership project ACM Adaptive coding and modulation BBE Background block error BER Bit error rate bit/s bits per second CQI Channel quality information DVB Digital video broadcasting DVB-S2 Second generation digital video broadc
11、asting via satellite DVB-RCS DVB-return channel via satellite EB Errored block EN European standard ES Errored second ETSI European Telecommunications Standards Institute FER Frame error rate GEO Geostationary earth orbit LTE Long term evolution PER Packet error rate SES Severely errored second SNR
12、Signal-to-noise ratio TR Technical report TS Technical specification Lb Length of a block Lp Length of a packet 2 Rec. ITU-R S.2099-0 Nbit_allow Allowable number of bit errors Npacket_allow Allowable number of packet errors Rb Information bit rate expressed in bit/s Rp packet rate, number of packets
13、 per second Pb_req Required BER Pp_req Required PER Related ITU Recommendations, Reports and Resolutions Recommendation ITU-R S.614-4 Allowable error performance for a satellite hypothetical reference digital path in the fixed-satellite service operating below 15 GHz when forming part of an internat
14、ional connection in an integrated services digital network Recommendation ITU-R S.1061-1 Utilization of fade countermeasure strategies and techniques in the fixed-satellite service Recommendation ITU-R S.1062-4 Allowable error performance for a satellite hypothetical reference digital path operating
15、 below 15 GHz Recommendation ITU-R S.1323-4 Maximum permissible levels of interference in a satellite network (GSO/FSS; non-GSO/FSS; non-GSO/MSS feeder links) in the fixed-satellite service caused by other codirectional FSS networks below 30 GHz Recommendation ITU-R SF.1006 Determination of the inte
16、rference potential between earth stations of the fixed-satellite service and stations in the fixed service Recommendation ITU-T G.826 End-to-end error performance parameters and objectives for international, constant bit-rate digital paths and connections The ITU Radiocommunication Assembly, conside
17、ring a) that developments in satellite communications have required the specification of short-term interference criteria; b) that short-term performance objectives can be used to develop short-term interference criteria; c) that satellite link performance must be sufficient to allow compliance with
18、 overall end-to-end performance objectives and end-user requirements; d) in defining error performance criteria, it is necessary to take into account all foreseeable error-inducing mechanisms, especially time-varying propagation conditions and interference, recognizing a) that long-term error perfor
19、mance objectives have been provided in Recommendations ITU-R S.614 and ITU-R S.1062; b) that information on adaptive transmission and power control techniques which can be used to counteract time-varying attenuation has been provided in Recommendation ITU-R S.1061; Rec. ITU-R S.2099-0 3 c) that info
20、rmation on the time-allowance for the bit error rate (BER) specified in the short-term performance objectives, due to interference in a satellite network has been provided in Recommendation ITU-R S.1323; d) that information on the short-term interference criteria applicable for interference between
21、fixed-satellite service earth stations and stations in the fixed service has been provided in Recommendation ITU-R SF.1006, recommends 1 that the number of bit errors during the short-term period, Nbit_allow be no greater than RbPb_req, when the service-dependent required performance is specified by
22、 bit error rate (BER) (see Note 1); 2 that the number of packet errors during the short-term period, Npacket_allow be no greater than RpPp_req, when the service-dependent required performance is specified by packet error rate (PER) (see Notes 2 and 3); 3 that the short-term period is defined as 1 se
23、cond for “bent-pipe” geostationary satellite links using adaptive coding and modulation (ACM); 4 that the short-term period can be shorter depending on the satellite orbit or the satellite transponder configuration, e.g. on-board processor (the minimum short-term period would be the end-to-end trans
24、mission time of one-hop); 5 that compliance with the Nbit_allow or Npacket_allow objective may be determined at the output of any functional blocks which are used to enhance error performance such as decoders and deinterleavers; 6 that the following Notes should be regarded as part of this Recommend
25、ation. NOTE 1 Rb is the information bit rate expressed in bits per second (bit/s) and Pb_req is the required BER of the service provided by the satellite system. NOTE 2 The term “packet” may be used as the same meaning as “frame” if the service-dependent required performance is specified by frame er
26、ror rate (FER). NOTE 3 Rp is the number of packets per second and it is the same as Rb divided by the number of bits per packet, and Pp_req is the required PER of the service provided by the satellite system. NOTE 4 The Pb_req and Pp_req are service and application dependent values, and to achieve o
27、ne of these values a suitable power margin should be used. NOTE 5 The relationship between Nbit_allow or Npacket_allow and the definitions of the terms used in Recommendation ITU-R S.1062 (Recommendation ITU-T G.826), including severely errored seconds and background block error rate can be found in
28、 1.3 of Annex 1. 4 Rec. ITU-R S.2099-0 Annex 1 Short-term error performance objectives for satellite communication systems 1 Background 1.1 Definition of short-term in satellite systems Satellite systems may be equipped with adaptive coding and modulation (ACM) scheme and/or power control scheme to
29、suitably counteract channel fading. Especially if they are operated in the frequency range over 10 GHz, adoption of ACM may be considered as a mandatory option to counteract severe rain fading. As detailed in Recommendation ITU-R S.1061 Utilization of fade countermeasure strategies and techniques in
30、 the fixed-satellite service, an adaptive rain fade compensation system is required to predict in advance the amount of rain attenuation or the signal quality taking into account the round-trip delay. Assuming the round-trip delay of 0.25 second of the geostationary earth orbit (GEO) satellite syste
31、m, the updating period of changing the modes (or estimating period of channel quality information (CQI) should not be much less than a second assuming the use of a “bent-pipe” transponder. The minimum interval will be 0.5 second in the case of GEO satellite. Fading or interference factors longer tha
32、n this period can be suitably detected and compensated with proper means. For satellite links not employing ACM, the short term interval can be defined as the transmission time for one hub-to-node link or approximately 0.25 second, for a geostationary satellite. A “hub” denotes a central station and
33、 a “node” denotes a remote station. Non-geostationary satellites will have reduced short-term intervals depending on the altitude of the satellites in the constellation. Therefore, if we limit our interests to popular GSO satellite systems, the period of short-term needs to be defined as 1 second. I
34、n addition, by referring to a recent satellite transmission specification by European Telecommunications Standards Institute (ETSI), a timing recovery loop is considered to have a response time on the order of 1 second, in the receiver terminal (see ETSI TR 102 768 V1.1.1 (2009-04), “Digital Video B
35、roadcasting (DVB); Interaction channel for Satellite Distribution Systems; Guidelines for the use of EN 301 790 in mobile scenarios”). 1.2 Short-term error performance objectives in terms of number of bit errors or packet errors By defining the short-term as 1 second, the performance objectives need
36、 to be defined by service dependent bit error rate (BER) or packet error rate (PER) performance, by considering prevailed multimedia services over satellite systems in the future. For example, the typical required BER performance for voice and data services are 103 and 106, respectively. More specif
37、ic examples of service dependent performance objectives can be found in Table 17 of the user guidelines for mobile users of DVB-RCS, ETSI TR 102 768 V1.1.1 (2009-04), and Table 6.1.7 of 3GPP LTE-Advanced system specification, 3GPP TS 23.203 v.11.12.0 (2013-12). The error rate requirements of the sec
38、ond generation digital video broadcasting via satellite (DVB-S2) is defined by PER, and a number of PER estimation results with various coding and modulation schemes are in the ETSI TR 102 376-1 V1.2.1 (2015-11). Rec. ITU-R S.2099-0 5 If the period of short-term is set to 1 second, the BER performan
39、ce due to fading or interference will be dependent upon the information rate. The higher the information rate is, the larger will be the number of bits that will be received that are corrupted by the interference or fading during a fixed interval. In order to maintain the required BER during the sho
40、rt-term period, the allowable number of bit errors, Nbit_allow can be estimated as follows: Nbit_allow = RbPb_req (1) where Rb is the information bit rate expressed in bits per second (bit/s) and Pb_req is the required BER defined by a specific service in the satellite system. Table 1 shows examples
41、 of the estimated Nbit_allow according to Rb and Pb_req, when the short-term period is defined as 1 second. TABLE 1 Allowable number of bits in error during the short time period, 1 second, according to the required BER Information rate, Rb Required BER, Pb_req Allowable number of bits in error, Nbi
42、t_allow 9.6 kbit/s 103 9 106 0 1.5 Mbit/s 103 1.5 103 106 1 155 Mbit/s 103 1,5 105 106 1.5 102 1 Gbit/s 103 1.0 106 106 103 If the system performance requirement is defined by PER (or FER), the allowable number of packet errors, Npacket_allow, in order to maintain the required PER during the short-t
43、erm period can be estimated as follows: Npacket_allow = RpPp_req (2) where Rp is the number of packets per second and it is Rp = Rb/Lp, where Lp is the length of a packet in number of bits. Pp_req is the required PER defined by a specific service in the satellite system. A typical size of MPEG packe
44、t is 188 bytes. 1.3 Relationships between the terms used in this Recommendation and those used in Recommendation ITU-R S.1062 Recommendation ITU-R S.1062 used performance parameters which were originally defined in Recommendation ITU-T G.826. Each of the parameters can be expressed in terms of the p
45、erformance measures, Nallow, Rb, and Pb_req used in this Recommendation. 1.3.1 Error performance events for paths An errored block (EB) is defined as a block in which one or more bits are in error. General definitions and examples of the blocks are found in Table 1 of Recommendation ITU-T G.826. The
46、 length of a block is in the range of 800 to 30 000 bits depending on the service rate. If the length of a bock is defined by Lb, then an EB is a block in which LbPb_req or LbPp_req is greater than or equal to 1, for a 1 second short-term interval. 6 Rec. ITU-R S.2099-0 An errored second (ES) is def
47、ined as a 1 second period with one or more EBs. During an ES, Nbit_allow or Npacket_allow is always greater than or equal to 1, for a 1 second short-term interval. A severely errored second (SES) is defined as a 1 second period which contains 30% or more EBs or at least one defect (see Recommendatio
48、n ITU-T G.826 for definition of defects). Note that SESs are a sub-set of ESs. A background block error (BBE) is defined by an EB not occurring as part of an SES. 1.3.2 Error performance events for connections An errored second (ES) is defined by a 1 second period in which one or more bits is in err
49、or or during which a loss of signal or alarm indication signal is detected. During ES, Nbit_allow or Npacket_allow is always greater than or equal to 1, for a 1 second short-term interval. Severely errored second (SES) is defined by a 1 second period which has a BER of greater than or equal to 103. During SES, Nbit_allow is always greater than or equal to Rb103. 2 Operational principles of ACM Due to time-varying characteristics of wireless channels, ACM schemes are considered in most of the modern satellite communication systems. Emplo
