CEPT
Doc. SE7(14)063
ECC
Electronic Communications Committee
PT SE7 Meeting
24-25 June 2014
ECO, COPENHAGEN
Date issued: 18 June 2014
Source: Lithuania
Subject: Impact of Aeronautical Telemetry systems on MFCN SDL operating cochannel in 1452-1492 MHz band
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Summary
This study investigates the impact of Aeronautical Telemetry system on MFCN SDL
UE operating co-channel in the frequency band 1452-1492 MHz.
The results are based on Minimum Coupling Loss (MCL) calculations and MonteCarlo simulations.
This study shows that MFCN SDL UE can operate near to Telemetry system.
Proposal
For consideration and inclusion of provided calculation and simulation results in the
draft ECC Report paragraph 5.5 on L-band coexistence scenarios (ref. SE7(14)047).
Background
Compatibility and sharing studies in support of the activities on the harmonization of
the frequency band 1452-1492 MHz. With this study Lithuanian Administration would
like to contribute to the investigation of this issue.
1. INTRODUCTION
In Region 1, the frequency band 1429-1518 MHz is used for Fixed and Mobile (except
aeronautical mobile) services on a primary basis and the frequency band 1452-1492 MHz is
also used for Broadcasting and Broadcasting Satellite services on a primary basis limited to
digital audio broadcasting (see RR 5.345). In addition to the primary services listed in the
Table of Frequency Allocations, there is also additional allocation for the frequency band
1429-1535 MHz (RR footnote RR 5.342):
5.342
Additional allocation: in Armenia, Azerbaijan, Belarus, the Russian Federation,
Uzbekistan, Kyrgyzstan and Ukraine, the band 1429-1535 MHz, and in Bulgaria the band
1525-1535 MHz, are also allocated to the aeronautical mobile service on a primary basis
exclusively for the purposes of aeronautical telemetry within the national territory. As of 1 April
2007, the use of the band 1452-1492 MHz is subject to agreement between the
administrations concerned. (WRC-12).
The frequency band 1452-1492 MHz is proposed as a candidate band for terrestrial
mobile/fixed communications networks supplemental downlink (MFCN SDL) while allowing
individual countries to adapt to specific national circumstances in part of the band for terrestrial
broadcasting and other terrestrial applications.
MFCN SDL is a mobile broadband system, which by means of base station transmitters in the
network, uses unpaired spectrum in downlink to provide a supplemental downlink capacity to
carry comprehensive text, audio, images, data, sound and video content in general in a
unicasting, multicasting or broadcasting mode.
2. PURPOSE OF THIS DOCUMENT
This document presents the electromagnetic compatibility study between Telemetry system
airborne transmitters and MFCN SDL receivers in the frequency band 1452-1492 MHz from
co-channel compatibility scenario perspective. In the Draft ECC Report on L-band coexistence
(ref. SE7(14)047) this scenario is called:

Scenario S: Impact of Aeronautical Telemetry systems on MFCN SDL operating cochannel.
The Lithuanian Administration is concerned of the potential interference from aeronautical
telemetry airborne transmitters to MFCN SDL receivers in the frequency band 1452-1492
MHz. With this study our administration would like to contribute to the investigation of this
issue. The results of this study can be found in the following sections.
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3. MAIN PARAMETERS OF THE TELEMETRY AIRBORNE TRANSMITTER
There are two possible sources of the technical characteristics of telemetry airborne
transmitter parameters:

Recommendation ITU-R M.1459 - "Protection Criteria for Telemetry Systems in the
Aeronautical Mobile Service and Mitigation Techniques to Facilitate Sharing with
Geostationary Broadcasting-Satellite and Mobile-Satellite Services in the frequency
bands 1 452-1 525 MHz and 2 310 2 360 MHz".

Characteristics can be taken from the assignments of the Master International
Frequency Register (MIFR), as a MA class of station (airborne transmitting station),
from countries listed in RR 5.342 footnote.
These sources provide very different characteristics of telemetry systems. In order to ensure
the reliability of the results, the compatibility analysis was carried out using both sources.
Table 1. Parameters of telemetry airborne transmitter
ITU-R M.1459
Central frequency, MHz
Master International
Frequency Register (MIFR)
1474.5
Channel bandwidth, MHz
5
21.3
Maximum antenna gain, dBi
10
No information. Assumed
according to ITU-R M.1459
EIRP, dBW
23.98
25.15
Maximum antenna height, m
10000
10000
Omnidirectional
Omnidirectional
Up to 320
Up to 600
Antenna type
Transmission path length, km
The telemetry airborne transmitter ideally uses isotropic antenna to cover all possible radiation
angles toward the telemetry receiving station. However, in practice, multiple reflections and
specific form of the airborne fuselage (possible physical blockage, metallic surface and etc.)
can cause large variations in the antenna gain pattern GTx (compared to Gmax=10dBi).
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Figure 1. Airborne telemetry transmitting antenna gain variations
For example, the probability of GTx= 0 dBi is P(G≤GTx=0dBi)=0.96. Such antenna gain
variation can have significant influence to the results of this analysis. In this study two different
telemetry transmitter antenna gain were used:

Gmax=10dBi as maximum antenna gain according to the ITU-R M.1459;

Gpossible=0dBi as antenna gain in near real case scenario.
It was assumed that antenna type is omnidirectional in both cases.
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4. MFCN SDL CHARACTERISTICS
The harmonised frequency arrangement is based on a block size of 5 MHz, resulting in the
following 8 frequency blocks in frequency band 1452-1492 MHz (ECC/DEC/(13)03).
Table 2. Harmonised frequency arrangement for MFCN SDL in frequency band 1452-1492
MHz
1452 -1457 1457-1462 1462-1467 1467-1472 1472-1477 1477-1482 1482-1487 1487-1492
Supplemental DownLink (SDL)
40 MHz (8 blocks of 5 MHz)
The technical characteristics and protection criteria for SDL receivers are taken from Draft
ECC Report on L-band coexistence scenarios (ref. SE7(14)047), ETSI TS 136 101 V11.8.0
(2014-04), ECC Report 191, CEPT Report 40 and ECC Report 82.
Table 3. Parameters for MFCN SDL UE in frequency band 1452-1492 MHz
Parameter
Value
Source
Antenna height
1.5 m
ECC Report 82
CEPT Report 40
ECC Report 191
Antenna gain
-4 dBi
ECC Report 191
Antenna pattern
Omnidirectional
ECC Report 82
CEPT Report 40
Body loss
3 dB
ECC Report 191
Building wall loss
10 dB
ECC Report 191
Buildings blocking for outdoor
UE (only urban)
7 dB
Walfisch-Ikegami Propagation
Model
Receiver bandwidth
5 MHz
Size of frequency block
Receiver Temperature
(kTB)
-107 dBm
Draft ECC Report on L-band
Receiver noise Figure
9 dB
ECC Report 191
Receiver Thermal Noise
Level
-98 dBm
ETSI TS 136 101 V11.8.0
Draft ECC Report on L-band
I/N Target
0 dB
ECC Report 191
Target Desensitization
DTARGET = 3dB
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5. MINIMUM COUPLING LOSS (MCL) ANALYSIS
The impact of Aeronautical Telemetry Tx on MFCN SDL UE Rx operating co-channel was
analysed in this study. The required separation distances were calculated.
This section shows the calculation results using Minimum Coupling Loss method based on the
deterministic link budget analysis. The calculated results are isolation in dB, which were
converted into a physical separation distance using Free Space Loss propagation model.
RPC = Ptx - Srx + Grx - BodyLoss + BCF.
(1)
Where:
RPC - Required Path Loss,
Ptx - EIRP of interferer,
Srx - victim noise level,
Grx - victim antenna gain,
BodyLoss - considered as 3 dB,
BCF - Bandwidth Correction Factor.
4 different situations were analysed in this section:
a) Rural outdoor.
b) Rural indoor. Additionally building wall loss of 10 dB (ref. ECC Report 191) was
considered.
c) Urban outdoor. Additionally building blocking of 7 dB (UE not in line-of-sight; ref.
Walfisch-Ikegami Propagation Model) was considered.
d) Urban indoor. Additionally building wall loss of 10 dB and building blocking of 7 dB (UE
not in line-of-sight) was considered.
Parameters of telemetry airborne transmitters for these calculations were taken from Table 1:
according to ITU-R M.1459 recommendation and Master International Frequency Register
(MIFR). Two different antenna gains for telemetry transmitter were used in calculations
according to ITU-R M.1459 recommendation.
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Calculation results are shown in the table below:
Table 4. Protection distances (km) for MFCN SDL User Equipment from MCL analysis
According to ITU-R M.1459 (GTx=10dBi)
Urban case
Indoor
41
Rural case
Outdoor
Indoor
Outdoor
128
91
287
According to ITU-R M.1459 (GTx=0dBi)
Urban case
Indoor
Rural case
Outdoor
13
41
Indoor
Outdoor
29
91
According to Master International Frequency Register (MIFR)
Urban case
Indoor
23
Rural case
Outdoor
Indoor
Outdoor
71
50
159
The calculation results show significant variation of required protection distance for MFCN
SDL User Equipment depending on the parameters of telemetry system (according to
recommendation ITU-R M.1459 and MIFR). Required separation distance can differ almost
twice. It should be noted that telemetry station parameters in MIFR differs from values given in
ITU-R M.1459 recommendation and not sufficiently describe the telemetry system (information
about antenna gain function is missing).
Compatibility studies based only on the MCL approach are often based on worst case
assumptions leading to very large separation distances. The usage of MCL method in this
situation (Telemetry Tx interferes SDL Rx) seems too strict. The telemetry airborne transmitter
will not always influence SDL Rx, because telemetry airborne Tx moves (velocity up to 1000
km/h [See document CPG-PTD(14)125]) in the area up to 320 km (according to ITU-R
M.1459) or up to 600 km (according to MIFR). It is not a permanent interference. Monte-Carlo
simulations using SEAMCAT software tool could show more realistic picture of interference
potential.
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6. INTERFERENCE SCENARIO FOR SEAMCAT
The interference scenario created in SEAMCAT is shown in the figure below.
Cell
Radius
Telemetry Rx
Separation
distance
Max
transmission
path
SDL BS
Interfering Link
Victim Link
SDL UE
Telemetry Tx
Figure 2. Interference scenario
The simulations were carried out using 500,000 randomly generated snapshots. Using
SEAMCAT tool worst cases (rural outdoor) from MCL calculations (See Table 4) were
analyzed.
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Simulation results with different separation distances (separation
SEAMCAT ≤ MCL separation distances) are presented in Table 5.
distances
in
Table 5. Simulations results using Monte-Carlo approach
Pessimistic scenario
Min separation distance
between ILT1 and VLR2,
km
Probability of interference,
%
Near real case scenario
Min separation distance
between ILT1 and VLR2,
km
Probability of interference,
%
Real scenario
Min separation distance
between ILT1 and VLR2,
km
Probability of interference,
%
MIFR scenario
Min separation distance
between ILT1 and VLR2,
km
Probability of interference,
%
According to ITU-R M.1459 (GTx=10dBi)
287 (result of MCL
calculations)
220
190
0
3.94
6.78
According to ITU-R M.1459 (GTx=0dBi)
91 (result of MCL calculations)
40
0
0
1.65
3.68
According to ITU-R M.1459 (EIRP of the telemetry Tx
according to the gain probability function. See Fig. 2)
80
40
0
0.04
0.38
1.37
According to Master International Frequency Register
(MIFR)
159 (result of MCL
calculations)
50
0
0
1.97
3.31
Note1: ILT - Interfering Link Transmitter (See Figure 2).
Note2: VLR - Victim Link Receiver (See Figure 2).
SEAMCAT simulation’s results show that the separation distance between telemetry airborne
Tx and MFCN SDL UE Rx can be significantly reduced keeping acceptable interference level
at MFCN SDL User Equipment.
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7. CONCLUSIONS
The results of analysis using MCL calculation method show significant variation of required
protection distance for MFCN SDL User Equipment depending on the parameters of telemetry
system (according to recommendation ITU-R M.1459 and MIFR). Required separation
distance can differ almost twice.
The results of simulation using Monte-Carlo method show that MCL method seems too strict,
since telemetry airborne Tx interferes MFCN SDL UE Rx not permanently. Monte-Carlo
simulations show that separation distance can be significantly reduced keeping acceptable
interference level at MFCN SDL User Equipment receiver (See Table 5).
This study shows that MFCN SDL UE can operate near to Telemetry systems. The
compatibility is feasible.
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