1、 Report ITU-R S.2151(10/2009)Use and examples of systems in the fixed-satellite service in the event of natural disasters and similar emergencies for warning and relief operations S SeriesFixed-satellite serviceRep. ITU-R S.2151 ii Foreword The role of the Radiocommunication Sector is to ensure the
2、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 Recommendations are adopted. The regulatory and policy functions of the Rad
3、iocommunication 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 described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex
4、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 the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent inf
5、ormation database can also be found. Series of ITU-R Reports (Also available online at http:/www.itu.int/publ/R-REP/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 Fi
6、xed 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 Frequency sharing and coordination between fixed-satellite and fixed service system
7、s SM Spectrum management Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2009 ITU 2009 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written pe
8、rmission of ITU. Rep. ITU-R S.2151 1 REPORT ITU-R S.2151 Use and examples of systems in the fixed-satellite service in the event of natural disasters and similar emergencies for warning and relief operations (2009) TABLE OF CONTENTS Page 1 Introduction 2 2 The use of small aperture earth stations fo
9、r relief operation in the event of natural disasters and similar emergencies 2 2.1 Introduction. 2 2.2 Basic considerations . 2 2.2.1 Required services . 2 2.2.2 Channel and physical layer requirements 2 2.2.3 Network requirements 3 2.2.4 Associated earth station . 3 2.3 Required earth station e.i.r
10、.p. levels and satellite resources . 3 2.3.1 Example of link budget calculation . 8 2.4 Configuration of the transportable earth station . 10 2.4.1 Weight and size 10 2.4.2 Antenna 10 2.4.3 Power amplifier 10 2.4.4 Low-noise receiver. 11 2.5 Examples of transportable earth station realizations and s
11、ystem implementation . 11 2.5.1 Small transportable earth stations 11 2.5.2 Example of an emergency network and associated earth stations . 13 3 An example describing use of FSS system for warning operations in the event of natural disasters and similar emergencies 18 3.1 Earthquake Early Warning Sy
12、stem. 18 3.2 Satellite delivery . 20 3.2.1 Advantage of the satellite network. 20 3.2.2 Example of the system for satellite delivery 20 3.3 Case examples of the EEW satellite delivery service. 22 3.4 Further development of the satellite delivery system . 22 4 Conclusions 23 2 Rep. ITU-R S.2151 1 Int
13、roduction This Report describes how fixed-satellite service (FSS) systems can provide disaster relief radiocommunications. When developing a new FSS system in preparation to respond to natural disasters, the technical characteristics of the satellite(s) to be accessed should be considered in the des
14、ign of such FSS system. In 2 of this Report, the summary of system design and examples of characteristics of systems using small aperture earth stations are provided. Additionally, since FSS systems are inherently suitable for data delivery, they are expected to be utilized for warning operations. I
15、n 3 of this Report, the outline of an earthquake early warning system is provided as an example of warning operations using FSS system. FSS systems operate in general on frequency bands as identified in Recommendation ITU-R S.1001. 2 The use of small aperture earth stations for relief operation in t
16、he event of natural disasters and similar emergencies 2.1 Introduction In the event of natural disasters, epidemics and famines, etc., there is an urgent need for a reliable telecommunication link for use in relief operations. Satellite appears as the most appropriate means to quickly set up a telec
17、ommunication link with remote facilities. The main requirements of such a satellite system are discussed here. Assuming the system is to operate in the FSS, it is desirable that a small earth station, such as a fixed VSAT, a vehicle-mounted earth station or a transportable earth station, with access
18、 to an existing satellite system, should be available for transportation to, and installation at, the disaster area. It is also desirable that the system relies on widespread standards so that: equipment is readily available; interoperability is ensured; reliability is ensured. This 2 provides mater
19、ial that may be useful in planning the use of systems in the FSS in the event of natural disasters and similar emergencies for warning and relief operations. 2.2 Basic considerations 2.2.1 Required services The basic telecommunication architecture for relief operations should be composed of a link c
20、onnecting the disaster area with designated relief centres, and its basic telecommunication services should comprise at least telephony, any kind of data (IP, datagrams, facsimile, .), video. For such transmission, digital transmission technologies are employed in most cases. 2.2.2 Channel and physi
21、cal layer requirements In digital transmissions, one means to measure the performance of the coded channel is the bit error probability (BEP). The recommended objective BEP in the FSS provided in Recommendation ITU-R S.1062 is 106for 99.8% of time in the worst month. This BEP results both from the s
22、ignal-to-noise and interference ratio (SNIR), which is the performance of the channel, and from the coding. Appropriate coding can compensate, to a certain extent, for poor channel quality but lowers the useful bit rate. Rep. ITU-R S.2151 3 The particular conditions of transmission in the place of a
23、 disaster in case of both warning and relief operation (e.g. climate of site, nature of mission, ), which might degrade the channel quality, should be taken into account by reinforcing coding. The ideal would be to have adaptive coding, i.e. a system able to get back information from the channel and
24、 to respond by adapting the coding rate. 2.2.3 Network requirements For relief operations, due to the essential requirement of having small antennas, it is preferable to operate the network in the 14/12 GHz band or even in the 30/20 GHz band. Although the bands such as 6/4 GHz require larger antenna
25、s, they are also suitable depending on conditions of transmission and coverage of satellite resources. In order to avoid interference, it should be taken into account that some bands are shared with terrestrial services. The network should offer suitable quality of service. In case the network is sh
26、ared with customers having non-urgent needs, the emergency operations should have absolute priority which means a “pre-emption” class of service. A fully private network, with reserved frequency bands and facilities, could be desirable. When the number of operational earth stations is large, a netwo
27、rk control based on demand assignment multiple access (DAMA) may be necessary. 2.2.4 Associated earth station For (a) small earth station(s) on site, a vehicle-mounted earth station or a transportable earth station should be considered. The material provided in 2.3 to 2.6 may be useful for sizing of
28、 such earth stations. For the smooth operation of earth stations in the event of a disaster, regular training for potential operators and preparatory maintenance of the equipment is essential. Particularly, special attention should be given to the inclusion of autonomous battery or power systems. 2.
29、3 Required earth station e.i.r.p. levels and satellite resources In 2, required earth station e.i.r.p. levels and satellite resources are studied by link budget calculations based on the assumption that a small earth station (a fixed VSAT, a vehicle-mounted earth station or a transportable earth sta
30、tion) operating in the disaster area communicates with a hub earth station equipped with a larger antenna. The choice of system parameters should be based on considerations listed in 2.3 for the 6/4 GHz band, the 14/12 GHz and the 30/20 GHz band. The system parameters are listed in Table 1a) to 1f).
31、 QPSK with rate 1/2 convolutional code, 3/4 convolutional code, 1/2 convolutional code + 188/204 Reed Solomon outer code and 1/2 turbo code are typical digital modulation and FEC methods commonly used for FSS satellite links. It is worth stressing that the combination of a convolutional code as the
32、inner code with a Reed-Solomon code as the outer code is now rendered obsolete by turbo coding or low density parity check (LDPC) coding which performs better in general; the former coding scheme is surviving as a past legacy. The antenna diameter of a small earth station (vehicle-mounted or transpo
33、rtable) is assumed to be 2.5 m or 5 m for the 6/4 GHz band and 1.2 m or 3 m for the 14/12 GHz band and 1.2 m or 2.4 m for the 30/20 GHz band in this example of the link budget calculation. For 14/12 GHz and 30/20 GHz stations, smaller diameter antennas may be used if appropriate measures, such as sa
34、tellites with greater G/T or spread spectrum techniques are used to allow reduction of the off-axis emissions to acceptable levels. 4 Rep. ITU-R S.2151 In the 4 GHz band, a typical G/T of an earth station is 17.5 dB/K and 23.5 dB/K for the 2.5 m and 5 m antenna, respectively. In the 12 GHz band, a t
35、ypical G/T of an earth station is 20.8 dB/K and 28.8 dB/K for the 1.2 m and 3 m antenna, respectively. In the 20 GHz band, a typical G/T of an earth station is 25.1 dB/K and 31.1 dB/K for the 1.2 m and 2.4 m antenna, respectively. The noise temperature of low noise amplifier is assumed to be 60 K, 1
36、00 K and 140 K for the 4 GHz band, the 12 GHz band and the 20 GHz band, respectively. Although small aperture antennas such as 45 cm, 75 cm, etc. can be used, Radio Regulations (RR) including the off-axis limitation should be considered when using those antennas. The use of small antennas may not al
37、low meeting the off-axis emission criteria, therefore, the earth station transmit power should be reduced in order to avoid the interference to adjacent satellites and other services. It should be noted that values of satellite e.i.r.p. and earth station e.i.r.p. are for a small earth station with a
38、ntenna elevation 10 and 2 dB of the total margin. In Table 1f), typical satellite parameters for global beams in the 6/4 GHz band, spot beams in the 14/12 GHz band and the 30/20 GHz band are provided. The “transponder gain #a” and “transponder gain #b” in Table 1f), are defined as shown in Fig. 1. T
39、ABLE 1 Typical satellite, earth station, carrier parameter for calculation a) Distance to GSO satellite Elevation (degrees) 10 Distance (km) 40 600 b) Path loss (EL = 10) 6/4 14/12 30/20 Frequency (GHz) 4.0 6.2 12.25 14.25 20.0 30.0 Wavelength (m) 0.08 0.05 0.02 0.02 0.02 0.01 Path loss (dB) 196.7 2
40、00.5 206.4 207.7 210.6 214.2 c) Transmission channel parameter Modulation FEC QPSK 1/2 Conv.(1) QPSK 3/4 Conv.(1)QPSK 1/2 Conv.(1) QPSK 1/2 turbo coding 8-PSK 2/3 BER 10-610-610-610-610-6Required Eb/N0(dB) 6.1 7.6 4.4 3.1 9.0 FEC rate 0.5 0.75 0.5 0.5 0.67 Outer code rate 1.0 1.0 188/204 1.0 1.0 Num
41、ber of bits in a symbol 2 2 2 2 3 Required C/N (dB) 6.1 9.4 4.0 3.1 12.0 (1)Constraint length k = 7. Rep. ITU-R S.2151 5 TABLE 1 (end) d) Earth station antenna gain and G/T Frequency band (GHz) 6/4 14/12 30/20 Antenna diameter 2.5 m 5.0 m 1.2 m 3.0 m 1.2 m 2.4 m Frequency (GHz) 4.0 6.2 4.0 6.2 12.25
42、 14.25 12.25 14.25 20.0 30.0 20.0 30.0Efficiency 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Antenna gain (dBi) peak 38.2 42.0 44.2 48.0 41.5 42.8 49.5 50.8 45.8 49.3 51.8 55.3G/T (dB/K) 17.5 23.5 20.8 28.8 25.1 31.1 e) HUB earth station antenna gain and G/T Frequency (GHz) 6/4 14/12 30/20 4.0 6
43、.2 12.25 14.25 20.0 30.0 Antenna gain (dBi) 55.7 59.5 57.9 59.5 58.0 61.8 HUB earth station G/T (dB/K) 35.0 35.0 35.0 HUB earth station antenna size (m) 18 m 7.6 m 4.7 m f) The satellite transponder gain Satellite (GHz) 6/4 14/12 30/20 Frequency band (GHz) 6/4 14/12 30/20 Wavelength (m) 0.05 0.02 0.
44、01 Beam type GLOBAL SPOT Multi Satellite receive G/T (dB/K) 13.0 2.5 11.0 Transponder saturation e.i.r.p. for single carrier (dBW) 29.0 45.8 54.5 SFD (dB(W/m2) 78.0 83.0 98.4 IBO-OBO (dB) 1.8 0.9 5.0 Gs (dB) 37.3 44.5 51.0 Transponder gain #a (dB) 146.1 174.2 200.2 Transponder gain #b (dB) 55.3 33.5
45、 14.0 SFD: Saturation flux-density. IBO: Input back-off. OBO: Output back-off. 6 Rep. ITU-R S.2151 FIGURE 1 Definition of transponder gain (XP gain) Report 2151-01XP gain #a = + e.i.r.p. (satellite saturation) SFD + (IBO-OBO)Gs XP gain #b = satellite e.i.r.p. HUB eath station e.i.r.p.: Antenna gain
46、of 1 mGs2Satellite e.i.r.p. Earth station e.i.r.p.Earth stationtransmission powerHUBearth station e.i.r.p.Satellite bandwidthXP gain #aXP gain #bAs a result of link budget calculation of the outbound (hub-to-VSAT) and inbound (VSAT-to-hub) direction, Tables 2a), 2b) and 2c) provide examples of requi
47、red earth station e.i.r.p. levels and satellite resources including the required satellite e.i.r.p., the earth station e.i.r.p. and the bandwidth required for typical digital modulation and FEC methods in the 6/4 GHz band, the 14/12 GHz and the 30/20 GHz band. TABLE 2a Examples of the required earth
48、 station e.i.r.p. levels and satellite resources in 6/4 GHz band Modulation/FEC QPSK 1/2 Conv.(2) QPSK 3/4 Conv.(2)QPSK 1/2 Conv.(2)+RS QPSK 1/2 TC IR(1)Antenna diameter 2.5 m 5.0 m 2.5 m 5.0 m 2.5 m 5.0 m 2.5 m 5.0 m Allocated satellite bandwidth (kHz) 90 90 60 60 90 90 60 60 Satellite e.i.r.p. (dB
49、W) 6.8 0.9 8.3 2.4 6.8 0.9 8.3 2.4 Earth station e.i.r.p. (dBW) 46.2 46.2 47.7 47.7 46.2 46.2 47.7 47.7 64 kbit/s Earth station transmit power (W) 3.1 0.8 4.4 1.1 3.1 0.8 4.4 1.1 Allocated satellite bandwidth (kHz) 1 434 1 434 956 956 1 434 1 434 956 956 Satellite e.i.r.p. (dBW) 18.8 12.9 20.3 14.4 18.8 12.9 20.3 14.4 Earth station e.i.r.p. (dBW) 58.2 58.2 59.7 59.7 58.2 58.2 59.7 59.7 1 Mbit/s Earth station transmit power (W) 50.3 12.6 71.1 17.8 50.3 12.6 71.1 17.8 Allocated satellite bandwidth (kHz) 8 602 8 602 5 734 5 734 8 602 8 602 5 734 5 734 Satellit
