Frequency Sharing Study between FWA & FSS in the band 5725 - 5875 MHz David Bryant Wireless Networks Presentation to UK W-LAN Advisory Group (Sharing &
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Frequency Sharing Study between FWA & FSS in the band
5725 - 5875 MHz
David BryantWireless Networks
Presentation to UK W-LAN Advisory Group(Sharing & DFS sub-group)9th December 2002
© British Telecommunications plc, 2002 2
Sharing Studies performed Aggregate effect of FWA terminals radiating into
representative FSS satellite receivers
- INTELSAT IX (31.5o West) > 5850 MHz only
- Statsionar Express (14o West) - whole band
- INTELSAT VII (66o East) > 5850 MHz only
Effect of FSS earth station transmissions on FWA receivers
FWA: Mesh & Point-to-Multipoint systems considered
Sharing Scenario for FSS Earth-to-space Satellite Links sharing with FWA (e.g.Mesh or P-MP) networks in the 5725-
5875 MHz frequency band
FSS Satellite
FSS Earth Station
Wanted signal pathsInterference signal paths
Uplink FSS path
FWAOutdoor Terminals
GSO Orbit
Minimum elevation ~4 degrees
5GHz ‘Band C’ Spectrum Allocations
* Short range indoor data links + CCTV + movement detectors max 25 mW eirp.** Road Transport & Traffic Telematics.
RR Allocation
s
Frequency (MHz)57505725
Other service
s(UK &
Europe)5775 5825 5850
ISM
RADIOLOCATION Amateur
5875
Fixed Satellite Service (R1)(Earth-to-space)
FSMOBILE
SRDs* SRDs
FSS (Global)(Earth-to-
space)
5800
FS (Footnotes 5.453, 5.455, 5.456) Not UKLand Mobile (UK) (Footnote 5.451)
5795
5815
RTTT**
Fixed & transportable video links
UK nominalchannel
allocationsfor FWA
(under discussion)
20 MHz channel spacing
O/B(Max eirp 40 dBW, 20 MHz BW)
Parameter Value Source
Maximum mean EIRP 1 Watt ETSI TR 102 079
On-axis gain 10 dBi “
Off-axis gain envelope(gain @ elevation angle)
-25 dBi @ 60o-90o
-15 dBi @ 40o-60o
“
Off-axis gain (0o –40o) See Figure European AntennasVertical Omni
Mounting Roof-top -
Bandwidth 22 MHz ETSI TR 102 079
Radio Access TDD/TDMA “
Modulation OFDM “
Polarisation Linear (vertical) “
Peak-to-average power 6 dB “
Total Tx activity/node 5% “
Rx sensitivity (lowest) -78 dBm “
C/I 11 “
Maximum tolerableinterference
-89 dBm -
Table of ETSI FWA Mesh Radio Parameters for use in FSS Sharing Studies
UK draft spec in IR2006 is 2 Watts
Table of ETSI FWA PMP Radio Parameters for use in FSS Sharing Studies
Parameter Base Station Subscriber Terminal Source
Maximum peak EIRP 1 Watt 1 Watt ETSI TR 102 079
Reduction due toAutomatic Power Control
5 dB 5 dB “
On-axis gain 15 dBi 18 dBi “
Off-axis gain envelope(gain @ elevation angle)
See Figure See Figure European AntennasSectoral & Flat-plate
Mounting 0o elevation Some of these are mountedunder eaves, and indoors
ETSI TR 102 079
Bandwidth 22 MHz 22 MHz “
Radio Access TDD/TDMA TDD/TDMA “
Modulation OFDM OFDM “
Polarisation Linear (vertical) Linear (vertical) “
Duty ratio 60% 3% “
Rx sensitivity (mean) -88 dBm -85 dBm “
© British Telecommunications plc, 2002 7
Calculation of interference into satellite link
%xT
T
link
link
. . . . . . . . . . . . (1)
where,Tlink : apparent increase in the equivalent satellite link noisetemperature due to an interfering emission (K);
Tlink : the equivalent satellite link noise temperature (K)
x = 1%, 6% & 10%
• Standard method (used in satellite inter-coordination)
© British Telecommunications plc, 2002 8
Calculation of interference into satellite link(cont.)
• Gr , l : fairly insensitive to FWA location (in N.W. Europe)
• , Gr , Tlink : obtained from Satellite Advanced Filing Information(this should lead to conservative results)
• Work out maximum aggregate EIRP tolerable from FWA systems
© British Telecommunications plc, 2002 9
Elevation Plane Radiation Patterns for FWA Antennas at 5.8 GHz
Mesh Antenna:
Source: www.european-antennas.co.uk
© British Telecommunications plc, 2002 10
Elevation Plane Radiation Patterns for FWA Antennas at 5.8 GHz
Point-to-MultipointSubscriber Unit Antenna
Point-to-MultipointBase StationSectoral Antenna
Source: www.european-antennas.co.uk
Blue ring shows points where an FWA terminal or base station antenna would subtend an elevation angle of 20o to the Region 1 Statsionar Express Satellite in Geostationary Orbit at 14o West longitude
(global beam not shown)
Blue ring shows points where an FWA terminal or base station antenna would subtend an elevation angle of 5o to the INTELSAT VII satellite (IS-704) in Geostationary Orbit at 66o East longitude (uplink hemi-beam
also shown)(N.B. this satellite only operates in the portion of the band above 5850 MHz)
© British Telecommunications plc, 2002 13
Maximum No. of FWA devices deployable
39
,21
0,8
11
6,5
35
,13
5
9,0
32
,64
6
5,4
19
,58
8
90
3,2
65
1,8
06
,52
9,1
83
1,0
83
,91
7,5
10
18
0,6
52
,91
8
65
,35
1,3
51
10,000
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
10,000,000,000
10 6 1
Increase in Satellite Link Noise Temperature due to FWA Emissions (%)
No
. o
f F
WA
De
vic
es
pe
rmit
ted
FWA Mesh (ETSI spec.)
FWA PMP cells
FWA PMP Subscriber Units
Satellite: Statsionar Express 2 @ 14o WestRange of elevation angles from the UK: 23o-33o
© British Telecommunications plc, 2002 14
Maximum No. of FWA devices deployableSatellite: INTELSAT IX @ 31.5o West (>5850 MHz only)
Range of elevation angles from the UK: 20o-28o
11,7
04
,04
4
1,9
50
,67
4
99
5,1
69
59
7,1
01
99
,51
7
19
9,0
33
,77
2
119
,42
0,2
63
19
,90
3,3
77
19
,50
6,7
39
10,000
100,000
1,000,000
10,000,000
100,000,000
1,000,000,000
10 6 1
Increase in Satellite Link Noise Temperature due to FWA Emissions (%)
No
. o
f F
WA
De
vic
es
pe
rmit
ted
FWA Mesh (ETSI spec.)
FWA PMP cells
FWA PMP Subscriber Units
© British Telecommunications plc, 2002 15
Maximum No. of FWA devices deployableSatellite: INTELSAT VII @ 66o East (>5850 MHz only)
Range of elevation angles from the UK: 4o-7o
64
,28
9
10
,71
5
16
,18
3
9,7
10
1,6
18
3,2
36
,58
8
1,9
41
,95
3
32
3,6
59
10
7,1
49
1
10
100
1,000
10,000
100,000
1,000,000
10,000,000
10 6 1
Increase in Satellite Link Noise Temperature due to FWA Emissions (%)
No
. o
f F
WA
De
vic
es
pe
rmit
ted
FWA Mesh (ETSI spec.)
FWA PMP cells
FWA PMP Subscriber Units
© British Telecommunications plc, 2002 16
Effect of aggregate interference on C/I of FSS carrier
Real example, UK - Hong Kong satellite circuit via 66o
East Satellite C/Nup = 22.7 dB;
C/Ndown = 15.52 dB;
C/Nintermod = 30 dB;
C/Nother interference = 27 dB;
Gives at the distant receiving earth station, C/Ntotal = 14.4 dB;
Wanted carrier bandwidth: 27 MHz
When the effects of the FWA interference are included, i.e.,
EIRPFWA in bandwidth of 20 MHz = 33.5 dBW for Tlink/Tlink = 10%
Wanted earth station uplink EIRP (in bandwidth of 27 MHz) = 76.8 dBW
C/IFWA = 43.3 dB
Hence, the aggregate effect of the FWA devices has a quite negligible impact on the qualityof the satellite circuit.
• Single example but T/T of 10% doesn’t seem too onerous
Locations where an FWA Mesh receiver could suffer excessive (Long-term) interference in the band 5850 – 5875 MHz fromEarth station transmissions at Martlesham Teleport Earth Station in East Anglia
(Earth station antenna pointing towards ISVII satellite at 66o East longitude; 10 km NGR grid overlay))The calculations use Rec. ITU-R P.452 to show areas (in red) where a mesh antenna located 8 metres above ground level could receive excessively high interference for 20% of the time due to
emissions from the MTP-10 antenna with an assumed transmit power into the antenna feed flange of 24 dBW. The yellow area is the reduced area in which interference would occur for a 15 dB increase in coupling loss (e.g. due to additional clutter loss along the path).
© British Telecommunications plc, 2002 18
Conclusions
Sharing between the FSS and FWA systems appears favourable in the band 5725 - 5850 MHz
- This is mainly due to the directional properties of FWA antennas in the elevation plane.
Top 25 MHz of Band C (5850-5875 MHz) is slightly less favourable:
- Because of the low elevation angles subtended into N.W. Europe by some satellites close to the horizon.
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