1、 Rep. ITU-R RS.2096 1 REPORT ITU-R RS.2096 Sharing of the 10.6-10.68 GHz band by the fixed and mobile services and the Earth exploration-satellite service (passive) (2007) TABLE OF CONTENTS Page 1 Introduction 2 2 EESS (passive) . 2 2.1 Applications 2 2.2 Passive sensor parameters. 2 2.3 Permissible
2、 interference criteria . 5 2.4 Current radio frequency interference in the 10.6-10.68 GHz. 5 3 Fixed and mobile service parameters . 6 3.1 Fixed service. 6 3.2 Mobile service 8 4 Simulation studies 8 4.1 General simulation methodology 8 4.2 Simulation study number 1. 9 4.2.1 Point-to-point FS system
3、s 11 4.2.2 Point-to-multipoint FS systems 14 4.3 Simulation study number 2. 17 4.4 Simulation study number 3. 19 4.4.1 Point-to-multipoint FS Systems . 19 4.4.2 Point-to-point FS systems 21 4.4.3 Mobile systems 23 4.5 Simulation study number 4. 24 4.5.1 Point-to-point FS systems 24 4.5.2 Mobile syst
4、ems 27 2 Rep. ITU-R RS.2096 Page 4.6 Summary of sharing study results. 31 5 Mitigation approaches 36 5.1 Earth exploration-satellite service (passive). 36 5.2 Fixed service. 38 5.3 Mobile service 40 6 Conclusions 40 7 Supporting ITU-R documents 41 1 Introduction The purpose of this Report is to summ
5、arize the results of the studies related to sharing of the 10.6-10.68 GHz band by the fixed and mobile services and the Earth exploration-satellite service (EESS) (passive). 2 EESS (passive) 2.1 Applications The band 10.6-10.7 GHz is of primary interest to measure rain, snow, sea state and ocean win
6、d for ocean and land surfaces. This frequency band is considered as an all-weather region suitable for using multispectral systems to establish surface material properties. Over land surfaces, the measurements performed at 10 GHz are suitable to estimate vegetation biomass once the soil moisture con
7、tribution is known. Over sea surfaces, the band at 10 GHz is adequate for measuring the sea surface and wind speed. In particular, measurements at 10 GHz providing wind speed measurements are essential to get accurate knowledge of sea surface temperature using the 6 GHz data offering the best sensit
8、ivity to sea surface temperature. A number of sensors are already using or are planning to use this frequency band in the near future for such measurements. These measurements are fully operational (regular use of the data, continuity of service, several usable data products) and are used on a world
9、wide basis. The retrieved data are used and exchanged between the meteorological organizations in all regions. It is to be noted that the retrieved parameters are actually derived from a set of measurements performed at five frequencies which are interrelated (6, 10, 18, 24 and 36.5 GHz). 2.2 Passiv
10、e sensor parameters Table 1 summarizes the parameters of conical scanning passive sensors that are or will be operating in the 10.6-10.68 GHz band as illustrated in Fig. 1. Rep. ITU-R RS.2096 3 TABLE 1 Passive sensor parameters Channel 10.6-10.7 GHz SENSOR 1 10 GHz AMSR-E CMIS Channel bandwidth (MHz
11、) 100 100 100 Pixel size across track (km) 56.7 27.5 42.9 Offset angle to the nadir or half-cone angle (degrees) 44.3 47.5 48.6 Incidence angle i at footprint centre (degrees) 52 55 58.1 Polarization H, V H, V H, V, R, L Altitude of the satellite (km) 817 705 833 Maximum antenna gain (dBi) 36 42 45
12、Reflector diameter (m) 0.9 1.6 2.2 Useful swath (km) 1 594 1 450 1 893 Half-power antenna beam width 3 dB (degrees) 2.66 1.4 1.02 Scan rate in rpm (rounds per minute) 20 40 31.6 H: horizontal V: vertical R: right L: left FIGURE 1 Geometry of conical scan passive microwave radiometers The antennas of
13、 passive sensors are modelled according to the following Figs. 2 to 4. 4 Rep. ITU-R RS.2096 FIGURE 2 SENSOR-1 antenna gain pattern at 10.6 GHz FIGURE 3 AMSR-E antenna gain pattern at 10.6 GHz FIGURE 4 CMIS antenna gain pattern at 10.6 GHz Rep. ITU-R RS.2096 5 2.3 Permissible interference criteria Re
14、commendation ITU-R RS.1029 Interference criteria for satellite passive remote sensing, recommends permissible interference levels and reference bandwidths for use in any interference assessment or sharing studies. The permissible interference levels for the 10.6-10.7 GHz band are 156 dBW in a refere
15、nce bandwidth of 100 MHz for current passive sensors, and 166 dBW in a reference bandwidth of 100 MHz for future passive sensors that are more sensitive than the currently operational passive sensors. The first number is indicated for sharing conditions circa 2003; while the second number is for sci
16、entific requirements that are technically achievable by sensors in the next 5-10 years. Recommendation ITU-R RS.1029 also specifies that these interference levels should not be exceeded for more than 0.1% of sensor viewing area, described as a measurement area of a square on the Earth of 10 000 000
17、km2unless otherwise justified. 2.4 Current radio frequency interference in the 10.6-10.68 GHz On a general basis, low levels of interference received at the input of passive sensors would degrade passive sensor operations acknowledging that, in particular, the sensors are not able to discriminate be
18、tween these natural radiations and man-made radiations. On the other hand, when levels of interference are very high, at several order of magnitude compared to the sensitivity, the corresponding levels may be detected as not natural and have to be disregarded. Figure 5 is a global composite image of
19、 radio-frequency interference (RFI) in different microwave frequencies derived from one month of AMSR-E sensor data (August 2004) (yellow is the 6-7 GHz and red 10.6 GHz). FIGURE 5 Radio frequency interference to AMSR-E passive sensor in the 6-7 GHz and 10.6 GHz bands This figure is based on the ana
20、lysis of both passive sensor measurements on the horizontal and vertical polarization for which a negative polarization differences (i.e. the difference between H and V polarizations) criteria of 5 K is used. Indeed, it is recognized that negative polarization higher than 5 K can only occur at these
21、 wavelengths through man-made emissions in H-polarization. From: Chris Kidd (Univ. Birmingham, UK) 6 Rep. ITU-R RS.2096 It should be noted that this figure only shows one form of interference (horizontal polarization emissions) and, overall, fails to show how extensive undetectable interference are.
22、 However it is reasonable to assume that in regions of extensive detectable RFI, it is likely to find larger areas of undetectable interference. Such detectable interference at high levels is therefore a symptom of a problem, but absence of detectable RFI does not imply that there is not a problem.
23、With regard to the potential interference level, acknowledging that these figures are presenting negative polarizations higher than 5 K, one can assume that, roughly, interference are, at a minimum, also higher than these 5 K (corresponding to 142 dBW/100 MHz). Considering the current interference t
24、hreshold as given in Recommendation ITU-R RS.1029 (i.e. 166 dBW/100 MHz corresponding to 0.02 K), it shows that these interferences are at least 24 dB above the threshold. In addition, Recommendation ITU-R RS.1029 also provides, for 10.6-10.7 GHz, a 0.1% percentage of area permissible interference l
25、evel may be exceeded over a 10 000 000 km2measurement area. Roughly considering the current impacted areas, one can show that the highly contaminated area already corresponds to 2.8%, also exceeding by far the area criteria (0.1%), stressing that other areas are contaminated without being detectable
26、 and are hence not considered in this estimation. In case of such interference, the assimilation models would have to cope with the following situation that would lead to corrupted meteorological forecasts: high level of interference, hence detectable, that would have to be disregarded but would hen
27、ce lead to a lack of data over certain area; undetectable levels of interference, more than likely to occur over large area, that would hence lead to corrupted data; pixels for which no interference or interference below Recommendation ITU-R RS.1029 threshold would be experienced, hence providing co
28、rrect data, further noting that the situation pertaining to the last two bullets will not be discriminated. 3 Fixed and mobile service parameters 3.1 Fixed service Tables 2 and 3 provide parameters of point-to-point (P-P) and point-to-multipoint (P-MP) FS systems, respectively, that were used in the
29、se compatibility studies. The band 10.6-10.68 GHz is used in France only by fixed wireless equipments in case of rupture of backhaul and repairs of FS links in other bands. This use is therefore limited and temporary. The last column of Table 2 provides the characteristics of these emergency P-P FS
30、links. Rep. ITU-R RS.2096 7 TABLE 2 Operating parameters of P-P fixed link equipment in the 10.6-10.68 GHz band Source Recommendation ITU-R F.758 Administration contributions Modulation 128-TM ASK, PESKY ASK, PESKY 4-PESKY FS Simulation case(1)1 2 3 4 5 6 Capacity (Mbit/s) 3.1 12.4 24.7 8 16 34 Chan
31、nel spacing (MHz) 0.8 2.5 5 7 14 14 Channels/80 MHz 100 32 16 12 6 6 Antenna gain (maximum) (dBi) 51 51 51 49 49 36-45 Feeder/multiplexer loss (minimum) (dB) 0 0 0 0 0 4 Antenna type Dish Dish Dish Dish Dish Dish Maximum TX output power (dBW) 3 3 3 2(2)2(2)7 e.i.r.p. (maximum) (dBW) 48(2)48(2)48(2)4
32、7(2)47(2)34 Receiver IF bandwidth (MHz) 0.8 2.5 5 7 14 20.4 Receiver noise figure (dB) 4 4 4 3 3 8 Receiver thermal noise (dBW) 141 136 133 132.5 129.5 113 Nominal Rx input level (dBW) 60 60 60 60 60 68 Rx input level for 1 103BER (dBW) 110 104 101 117 114 108 (1)This table entry is used as a refere
33、nce later in this Report in the description of certain simulation studies. (2)Except in certain specified countries, RR No. 5.482 limits the e.i.r.p. to 40 dBW and transmitter power to 3 dBW absent agreement under RR No. 9.21. Simulations run using the RR No. 5.482 power limits would result in inter
34、ference levels 7-8 dB lower than those indicated in Fig. 7. TABLE 3 Operating parameters of P-MP fixed link equipment in the 10.6-10.68 GHz band Parameter Central (hub) station Customer terminal station Modulation QPSK Access method Time division multiplex (TDM) Bandwidth/carrier 3.5 MHz 3.5 MHz Ant
35、enna type Sectoral antenna Dish Antenna gain (dBi) 13, backlobe 10 dBi 19-26 Antenna beamwidth 120 12-7 Number of active carriers/sector 5 5 Number of sectors 3 - Path length (km)(1)0.1-10Maximum transmit power per carrier (dBW) 10 10 Power control No Yes Receiving system line loss (dB) 0 0 Nominal
36、receiver input level/carrier (dBW) 110110 (1)Path lengths greater than 10 km are possible depending on environmental blockage factors. 8 Rep. ITU-R RS.2096 P-MP systems in this band are predominantly deployed in urban and suburban areas, with few if any systems in rural areas. Given the radio-freque
37、ncy block arrangements in Recommendation ITU-R F.1568, i.e. five block pairs, two of which overlap the band 10.6-10.68 GHz, and a typical wireless access cell radius of up to 10 km, one might expect a maximum of two wireless access networks operating in a given major urban/suburban area. According t
38、o the radio frequency channel arrangement, each block can have a bandwidth up to 25 or 30 MHz. In addition, the maximum number of terminal stations may be of the order of 300. The terminal and hub stations for these systems would not both be transmitting in the band 10.6-10.68 GHz, given that the ma
39、jority of P-MP systems will likely employ frequency division duplex (FDD) techniques. Antenna gain and beamwidths for P-MP terminal stations in this band are in the range 19-26 dBi, with 12 to 7 beamwidths. A typical terminal station antenna height in this band would be 20 m above ground level (roof
40、top mounts). This implies that a typical hub station antenna down-tilt angle will be of the order of 4 or less, below the horizontal plane. Consequently, three P-MP deployment configurations are possible for any urban/suburban area: Each of the two hub stations in a city area operates on one of the
41、two frequency blocks falling within the passive sensor bandwidth. One hub station operates on one of the frequency blocks falling within the passive sensor bandwidth, and 150 customer terminal stations operate on the other frequency block. No hub station operates on the frequency blocks falling with
42、in the passive sensor bandwidth, but the 150 customer terminal stations associated with each of the two hub stations do operate within the passive sensor band, for a total of 300 interfering transmitters for the city area. Customer terminal antenna gain and beamwidths for P-MP terminal stations in t
43、his band are in the range 19-26 dBi, with 12 to 7 beamwidths. A typical terminal station antenna height in this band would be 20 m above ground level (rooftop mounts). This implies that a typical hub station antenna down-tilt angle will be of the order of 4 or less, below the horizontal plane. 3.2 M
44、obile service Technical characteristics of mobile systems operating in the band 10.6-10.68 GHz are shown in Table 4. This band is especially used for occasional temporary P-P video links (including electronic news gathering, television outside broadcast and electronic field production), which may be
45、 considered as part of the mobile service. It is noted that the characteristics of such MS stations are very similar to the FS station characteristics assumed in the dynamic simulations, so that the conclusions of the FS studies are generally assumed to be applicable to the MS. 4 Simulation studies
46、4.1 General simulation methodology The current sharing studies employ dynamic model simulations with the results required by Recommendation ITU-R RS.1029 concerning the percentage of the area over a 10 million square kilometre measurement area that exceed the permissible interference power level. Th
47、ese dynamic model simulations develop cumulative distribution functions (CDFs) of received interference levels on the basis of such measurement areas so that such interference statistics can be directly compared with the specified interference criteria. Rep. ITU-R RS.2096 9 TABLE 4 Frequency band 10
48、.6-10.68 GHz ARIB standard STD-B33 STD-B33 STD-B11 Usage of omnidirectional antenna Channel spacing (MHz) 9 (SDTV) 18 (HDTV) 18 (HDTV) 18 Capacity (payload) (Mbit/s) Up to 30 Up to 60 Up to 66 Not available Modulation QPSK-OFDM 16-QAM-OFDM 32-QAM-OFDM 64-QAM-OFDM QPSK 16-QAM 32-QAM 64-QAM Not availa
49、ble Typical transmit antenna gain (dBi) 29-35 29-35 29-35 0 Transmit antenna type Parabolic Parabolic Parabolic Omni Transmit power (maximum) (dBW) 3 3 3 -3 EIRP (maximum) (dBW) 40 40 40 -3 Typical receive antenna gain (dBi) 29-35 29-35 29-35 Not available Receive antenna type Parabolic Parabolic Parabolic Not available Receive feeder loss (maximum) (dB) 1 1 1 Not available Receiver IF bandwidth (MHz) 9 18 18 Not available Receive noise figure (dB) 4 4 4 Not available Receiver thermal noise (dBW) 130.5 127.4 127.4 Not a
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