Simulation on Aggregate Interference Simulation on Aggregate Interference from Wireless Access Systems from Wireless Access Systems including RLANs into Earth including RLANs into Earth Exploration-Satellite Service in the Exploration-Satellite Service in the 5250-5350 MHz Band 5250-5350 MHz Band Spectrum Engineering Branch Spectrum Engineering Branch Industry Canada Industry Canada March, 2002 March, 2002 IEEE S802.16.2a-02/11 2002-03-08
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Simulation on Aggregate Interference from Wireless Access ...
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Simulation on Aggregate InterferenceSimulation on Aggregate Interferencefrom Wireless Access Systemsfrom Wireless Access Systems
including RLANs into Earthincluding RLANs into EarthExploration-Satellite Service in theExploration-Satellite Service in the
Overall Comparison of Allocations and provisions for RLANsOverall Comparison of Allocations and provisions for RLANsand other services in the 5GHz rangeand other services in the 5GHz range
Characteristics of EESS in the 5GHz rangeCharacteristics of EESS in the 5GHz range
�� Radar Radar scatterometersscatterometers�� useful for determining the roughness of largeuseful for determining the roughness of large
objects such as ocean wavesobjects such as ocean waves
�� Radio altimetersRadio altimeters�� used to determine the height of the Earth's landused to determine the height of the Earth's land
and ocean surfacesand ocean surfaces
�� Imaging radars (synthetic aperture radars)Imaging radars (synthetic aperture radars)�� used to produce high resolution images of land andused to produce high resolution images of land and
ocean surfaces.ocean surfaces.
�� In this analysis only one of the imaging radarsIn this analysis only one of the imaging radars(SAR 4-most sensitive) and altimeters were(SAR 4-most sensitive) and altimeters wereexaminedexamined
MS/ms – RLANs
FS/fs – FWA (R3)
EES
5250 5350 MHz
RADIOLOC
SRS
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Characteristics of Characteristics of SARsSARs in the 5 GHz range in the 5 GHz range
Characteristics of indoorCharacteristics of indoorWAS/RLANsWAS/RLANs
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Characteristics of Indoor WAS systemsCharacteristics of Indoor WAS systems
100%100%Active Ratio
18 dB18 dBBuilding loss
200 mW250 mWTransmitterpower
0 dBi0 dBiAntenna gain
Isotropic (for simulationpurposes)
Isotropic (for simulationpurposes)
Antenna
20 MHz20 MHzBandwidth
5.3 GHz5.3 GHzFrequency
ValueValueParameter
Indoor Type 2Indoor Type 1
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Distribution ofDistribution ofWAS/RLANsWAS/RLANs
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Distribution of WAS/RLANsDistribution of WAS/RLANs
�� Based on population data from the UN, cell radius ofBased on population data from the UN, cell radius ofWAS/RLANs and perceived deployment rate.WAS/RLANs and perceived deployment rate.Deployment factor of 30% was used. See ITU-R Doc.Deployment factor of 30% was used. See ITU-R Doc.8A-9B/838A-9B/83
�� City A (extremely large city)City A (extremely large city)�� Population = 17.6 millionPopulation = 17.6 million�� Include effects of stations operating in sub-urban areasInclude effects of stations operating in sub-urban areas
surrounding the city as well as to simulate effects of aggregatesurrounding the city as well as to simulate effects of aggregateinterference from stations operating in near-by cities, the radiusinterference from stations operating in near-by cities, the radiuswas extended from 54 km to approximately 81 km.was extended from 54 km to approximately 81 km.
�� City B (medium size city)City B (medium size city)�� Population = 3.7 millionPopulation = 3.7 million�� Radius of this city = approximately 12 km. An actual radius of 18Radius of this city = approximately 12 km. An actual radius of 18
km was used to account for effects from stations operating inkm was used to account for effects from stations operating insub-urban areas as well as effects from near-by cities.sub-urban areas as well as effects from near-by cities.
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Distribution of WAS/RLANsDistribution of WAS/RLANs
0.0660.0660.066Density (number of activesystems/km2)
6481312213122Deployment Area (km2)
43870870Number of active systems
Medium cityCity B
Large cityCity A
Large cityCity A
Outdoor
5.755.755.75Density (number of activesystems/km2)
76.576.576.5Deployment Area (km2)
440440440Number of active systems
Indoor Type 1Indoor Type 2Indoor Type 1Indoor
Case 3Case 2Case 1
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MethodologyMethodology
�� Within each cell:Within each cell:�� one station transmitting at all timesone station transmitting at all times
�� One-third of all transmitters has an additional scattering coefficientOne-third of all transmitters has an additional scattering coefficientof 17 dBof 17 dB
�� 3dB polarization loss for outdoor systems3dB polarization loss for outdoor systems�� 0dB polarization loss for indoor systems0dB polarization loss for indoor systems�� no atmospheric attenuation is assumedno atmospheric attenuation is assumed�� The satellite was simulated to run for a period of 30 days, the periodThe satellite was simulated to run for a period of 30 days, the period
of time in which the EESS would receive maximum interference wasof time in which the EESS would receive maximum interference wasthen revisited with time steps of 200 milliseconds. The resultsthen revisited with time steps of 200 milliseconds. The resultsshown here represent a period of time in which the EESS would beshown here represent a period of time in which the EESS would bevisible by the WAS systems in a single orbit in which EESS wouldvisible by the WAS systems in a single orbit in which EESS wouldexperience the maximum possible interference from the aggregateexperience the maximum possible interference from the aggregateinterference of WAS.interference of WAS.
�� Free space propagationFree space propagation�� Building loss = 18 dBBuilding loss = 18 dB
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SimulationSimulation
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Results of simulationResults of simulation
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Aggregate interference from indoor and outdoorAggregate interference from indoor and outdoorWAS into SAR 4 at 20 degrees from nadirWAS into SAR 4 at 20 degrees from nadir
Aggregate interference from WAS into SAR 4 at 20degree from nadir
Case 1: Iaggregate exceeds Icriteria for approximately 1.6 secondsCase 2: I aggregate exceeds I criteria for approximately 1.4 secondsCase 3: I aggregate exceeds I criteria for approximately 1 second
Case 1
Case 2
Case 3
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Aggregate interference from indoor and outdoorAggregate interference from indoor and outdoorWAS into SAR 4 at 55 degrees from nadirWAS into SAR 4 at 55 degrees from nadir
Aggregate Interference from WAS into SAR4 operating at 55 degrees from nadir
Case 1Case 3Case 2Case 1Case 3Case 2Case 1WAS(see Table 7)
AltimeterSAR 4 @ 55deg from nadirSAR 4 @ 20deg from nadirEESS
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ObservationsObservations
��Actual deployment of WAS indoor andActual deployment of WAS indoor andoutdoor is expected to be less than whatoutdoor is expected to be less than whatis assumed in this analysis.is assumed in this analysis.
��The result represents worst caseThe result represents worst caseinterference for the EESSinterference for the EESS�� interference is expected to be less at anyinterference is expected to be less at any
other time.other time.
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EIRP maskEIRP mask
�� Based on comparison of results between City A and City B, the EIRPBased on comparison of results between City A and City B, the EIRPmask for outdoor WAS can be increased by at least 3 dB and themask for outdoor WAS can be increased by at least 3 dB and theinterference criterion for the SAR should still be met for the vastinterference criterion for the SAR should still be met for the vastmajority of cities in the world. Hence, the EIRP mask can bemajority of cities in the world. Hence, the EIRP mask can bemodified as follows:modified as follows:-11 -11 dBWdBW/MHz/MHz 00°° ≤≤ θθ <5 <5°°-11 - 0.711(-11 - 0.711(θθ –5) –5) dBWdBW/MHz /MHz 55°° ≤≤ θθ < 40 < 40°°-35.9 - 1.222 (-35.9 - 1.222 (θθ - 40) - 40) dBWdBW/MHz/MHz 4040°° ≤θ≤θ < 45 < 45°°-42 -42 dBWdBW/MHz /MHz θθ ≥≥ 45 45°°where where θθ is the elevation angle above local horizon in degrees. is the elevation angle above local horizon in degrees.
�� However, since a maximum EIRP of 1W (-13 However, since a maximum EIRP of 1W (-13 dBWdBW/MHz) is allowed,/MHz) is allowed,the proposed EIRP mask then becomes…the proposed EIRP mask then becomes…
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Proposed EIRP mask for outdoorProposed EIRP mask for outdoorWAS/RLANsWAS/RLANs
�� Simulation performed for SAR 4 operating atSimulation performed for SAR 4 operating at55 degrees from nadir55 degrees from nadir
�� Assumed ALL of the WAS/RLANs wereAssumed ALL of the WAS/RLANs werepointing upward, although still using the EIRPpointing upward, although still using the EIRPmask as proposed.mask as proposed.
�� Pointing angles assumed: 0 to 10 and 0 to 20Pointing angles assumed: 0 to 10 and 0 to 20degreesdegrees
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Further simulationFurther simulation
Figure 2: Interference from indoor & outdoor WAS (including the effect of scattering) into SAR 4 (55 deg from nadir)
-200
-195
-190
-185
-180
-175
-170
-165
-160
-155
-150
-145
-140
-135
-130
-125
-120
-115
-110
-105
-100
0 100 200 300 400 500 600
seconds
I dB
W/M
Hz
0 deg
0 to 10 deg
0 to 20 deg
I criterion
23 sec
29 sec
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ConclusionConclusion
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ConclusionConclusion
�� With respect to sharing between EESS and WAS/RLANsWith respect to sharing between EESS and WAS/RLANsin the 5250-5350 MHzin the 5250-5350 MHz�� Sharing appears to be feasible given that indoor systems have aSharing appears to be feasible given that indoor systems have a
maximum EIRP of 250 maximum EIRP of 250 mWmW and that outdoor systems employ and that outdoor systems employcertain technical constraints such as the EIRP mask ascertain technical constraints such as the EIRP mask asproposedproposed
�� With respect to sharing between EESS and WAS/RLANsWith respect to sharing between EESS and WAS/RLANsin the 5470-5570 MHz rangein the 5470-5570 MHz range�� Further studies are required to examine the impact on widebandFurther studies are required to examine the impact on wideband
SARsSARs (SAR 2 and SAR 3) (SAR 2 and SAR 3)
�� Not covered in this presentation – sharing betweenNot covered in this presentation – sharing betweenWAS/RLANs and Radiolocation in the 5GHz rangeWAS/RLANs and Radiolocation in the 5GHz range