CEPT
ECC PT1(17)092
ECC
Electronic Communications Committee
ECC PT1 # 55
Berlin, Germany, 24-28 April 2017
Date issued:
19th April 2017
Source:
United Kingdom
Study of coexistence between IMT-2020 and EESS (s-E) GSO data relay
earth stations at 26 GHz
Subject:
Group membership required to read? (Y/N)
N
Summary:
This document provides an update to the UK study on compatibility between IMT-2020 stations and
a known EESS (s-E) data relay receiving earth station located in the UK, operating at 26 GHz.
The Analyses are provided under worst-case assumptions, for single-entry interference. The results
indicate that the areas within which interference could be caused are relatively small and therefore
co-existence is a matter for the national regulator concerned. Further studies to assess the impact of
aggregate interference are required.
Proposal:


To include this study in a joint CEPT contribution to the May 2017 meeting of ITU-R TG5/1
To update the UK study included in the PT1 26 GHz working document (Annex 1)
Background:
1
Introduction
This study provides a worst-case assessment of compatibility between a single transmitting IMT2020 station (base stations and user equipment) and a known EESS (s-E) data relay receiving
earth station located in Harwell, Oxfordshire, UK, operating at 26 GHz. The earth station operates
to a satellite in geostationary satellite orbit (GSO). The results are presented in the form of impact
areas, i.e. the areas around the earth station within which a single IMT-2020 station would cause
interference to the earth station in the absence of any additional mitigation.
2
IMT-2020 parameters
Tables 1 and 2 show the parameters of IMT-2020 used in this study. These parameters, for bands
between 24.25 GHz and 33.4 GHz, are taken from the liaison statement from ITU-R Working
Party 5D to ITU-R Task Group 5/1, which can be found in Attachment 2 of document ITU-R 5-1/36.
Base station
Parameter
Value
Frequency
26 GHz
Channel bandwidth
200 MHz
Antenna array
8x8 elements
Element gain
5 dBi
Main beam antenna gain
23 dBi
Conducted power (before Ohmic
loss) per antenna element
10 dBm
Array Ohmic loss
3 dB
Total output power
25 dBm
EIRP
48 dBm
Antenna height above ground
6m
Antenna down tilt
10 degrees
Antenna pattern
Recommendation ITU-R M.2101
Antenna relative gain towards horizon
(10 degrees off-axis)
EIRP density towards horizon
-8.5 dB
9.5 dBW/200 MHz
(-13.5 dBW/MHz)
Table 1. IMT-2020 base station transmitter parameters.
2
User equipment
Parameter
Value
Frequency
26 GHz
Channel bandwidth
200 MHz
Antenna array
4x4 elements
Element gain
5 dBi
Main beam antenna gain
17 dBi
Conducted power (before Ohmic
loss) per antenna element
10 dBm
Array Ohmic loss
3 dB
Total output power
19 dBm
EIRP
36 dBm
Antenna height above ground
1.5 m
EIRP density towards horizon
6 dBW/200 MHz
(-17 dBW/MHz)
Table 2. IMT-2020 user equipment transmitter parameters.
3
3
EESS (s-E) parameters
Table 3 shows the parameters of the EESS (s-E) data relay receiving earth station used in this
study. The physical characteristics are taken from the known earth station located at Harwell, UK
and the protection criteria is taken from the referenced ITU-R documents.
Parameter
Value
Frequency
26 GHz
Antenna diameter
6.8 m
Antenna centre height above
ground
6m
Antenna Gain
Antenna pattern
Reference
61.8 dBi
RR Appendix 8, Annex III
Earth station location
51.57775 N, -1.30478 E
Satellite GSO location
9⁰ East
I0/N0 (0.1% of time)
-6 dB
1
System noise temperature
300 K
2
Receiver system noise
-143.8 dBW/MHz
Interference criteria (0.1% of
time)
-149.8 dBW/MHz
References:
1 ITU-R document 7/16 – draft revision to Recommendation ITU-R SA.1155-1
2
ITU-R document 7/15 – draft revision to Recommendation ITU-R SA.1414-1
Table 3. EESS (s-E) data relay earth station receiver parameters.
4
4
Study assumptions and results
This study provides a worst-case assessment of compatibility between a single transmitting IMT2020 station (base stations and user equipment) and a known GSO EESS (s-E) data relay
receiving earth station located in Harwell, Oxfordshire, UK, operating at 26 GHz. The results are
presented in the form of impact areas, i.e. the areas around the earth station within which the
IMT-2020 station would cause interference to the earth station in the absence of any additional
mitigation.
4.1 Single-entry IMT-2020 interference
The assumptions used in this study provide a worst-case assessment of single-entry interference
impact. For example, we assume 100% network loading / activity, 0 dB body loss (for the user
equipment) and 0 dB polarisation discrimination. For the IMT-2020 base station, we assume a 10
degree downtilt with the azimuth orientated towards the receiving earth station. For the user
equipment, we assume the boresight radiation is directed towards the receiving earth station.
The propagation model used is Recommendation ITU-R P.452-16 with 50 metre resolution
terrain. No clutter is considered.
As can be seen in Figures 1 and 2 below, the sizes of the impact areas of the receiving earth
station with respect to a single IMT-2020 base station and user equipment are relatively small.
For the base station, the impact area is approximately 6 km across in the widest dimension and
for the user equipment impact area is approximately 4 km across.
In both cases, the edge of the impact area is regularly shaped in many places, which indicates
where the propagation is limited by free space path loss. Where the edge of the impact area
becomes irregular in shape, this indicates where diffraction by local terrain limits the extent of the
interference.
5
Figure 1. Impact area – single-entry IMT-2020 base station.
Figure 2. Impact area – single-entry IMT-2020 user equipment.
6
Analysis of Results
The study presented in this document provides a worst-case assessment of compatibility between
a single transmitting IMT-2020 station (base station and user equipment) and a known EESS
(s-E) GSO data relay receiving earth station located in Harwell, Oxfordshire, UK, operating at 26
GHz.
The analysis shows that for single-entry IMT-2020 interference, the size of the impact area around
the EESS (s-E) data relay receiving earth station is relatively small – approximately 6 km across
in the widest dimension in the case of the IMT-2020 base station.
In practice, the deployment of IMT-2020 at 26 GHz is likely to be in sub-urban or urban hot spots
only. It is also expected that only a small number of earth stations would be needed in each
country to downlink EESS data. If measures are taken, including locating EESS earth stations
away from urban areas, we expect that these EESS earth stations do not represent a barrier to
the introduction of IMT-2020 and that co-existence can be managed by the national regulator
concerned.
Further studies to assess the impact of aggregate interference are required.
7