Download Propagation models used in SEAMCAT studies (section 5.3)

CEPT
ECC
Electronic Communications Committee
ECC PT1(14)_CG003
ECC PT1
ECC PT1 #45
MCV Correspondence Group
Date issued:
30-06-2014
Source:
Orange
Subject:
Propagation model for MCV co-existence study
Password protection required? (Y/N)
N
Summary:
Based on technical analysis and simulations, the propagation models to be used for MCV co-existence
study are proposed.
Proposal:
It is proposed to use appropriate propagation models in the MCV co-existence study
Background:
At last web-meeting, propagation models were not agreed, it is agreed to perform further analysis
and consideration on the propagation models to be used in the co-existence study.
1.
Technical analysis and simulations
1). Propagation models and wall penetration losses used in ECC report 122
“Propagation models used in SEAMCAT studies (section 5.3)
Due to the fact that P.1546 model implemented in SEAMCAT does not have sea path option, a
free-space model was used instead as a worst case fallback option. Also Hata model was used
for some specific cases such as propagation in cluttered environment of the ship for scenario 3
(HATA SRD model) and when modelling signal distribution inside affected land-based networks
(rural propagation model).”
“Ship hull attenuation (section 7.3)
The interference signals from indoor v-BS and v-MS could be attenuated by the body structures
of the vessel (hull, walls, doors, windows, etc.). Different hull attenuation values must be
considered due to the different materials that might come in a way of GSMOBV emissions
emanating from inside the ship. For example, there is not the same level of attenuation when
the v-MS is close to a big panoramic window as when the v-MS is used somewhere in deep
inner corridors of the ship. Therefore interference analysis contained in annexes considered
different hull attenuation factors, such as 5, 10, 15, 20, 25 dB.”
2). Discussion on MCV wall penetration loss
According to the ITU-R P.1812 (chapter 4.9 Building entry loss) for the considered frequencies
(0,9 - 2,6 GHz) the median value of the entry loss is 11 dB with 6 dB standard deviation.
According to the ITU-R Rec.P.2040 (Effects of building materials and structures on radiowave
propagation above about 100 MHz) - the attenuation of metalic structure (Table 6 position 4) the
mean loss is 9,7 dB with standard deviation 6,3 dB. In Table 11 (Airport gate and office areas)
for the 2,59 GHz the entry loss is in the range from 11 to 28 dB.
Following ITU-R recommendation for adjacent service compatibility study, the penetration loss
for buildings (concrete, bricks, etc.), the recommended wall penetration loss is 11 dB with 6 dB
standard deviation, there is no special justification to use a ship wall penetration loss much
bigger than this ITU-R recommendation.
3). Propagation model for the path MCV BS UE
a) Indoor MCV BS to indoor MCV UE:
as agreed, the model to be used for indoor MCV BS to indoor MCV UE is
IEEE C-model with BP=15
b) Outdoor MCV BS to outdoor MCV UE
as agreed, the model to be used for indoor MCV BS to indoor MCV UE is
IEEE C-model with BP=15
c) Indoor MCV BS to outdoor MCV UE
as agreed, the model to be used for indoor MCV BS to indoor MCV UE is
IEEE C-model with BP=15
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Plus wall penetration loss = 11 dB with 6 dB stanadard deviation based on ITU-R
recommendation P.1812
Sensitivity analysis with wall penetration loss of 5, 10, 15, 20, 25 dB, as used in ECC report 122.
d) outdooroor MCV BS/UE to land UE/BS
Simulations using Method of Moments (MoM) have been done for evaluating wall penetration
loss from ship side wall which is modelled, the radiowave propagation is modelled and
simulated using MoM method. The calculation in the areas paralel to the direction of radiowave
propagation at height 1,5 m above sea level and distances 0m to 10 km are performed..
The simulated results for ship side wall which is modelled as metallic grid are given in annex 2.
The simulated results for ship side wall which is modelled as metallic surface are given in annex
3. It should be noted that when the victim receiving antenna height is 1.5 m (Land UE) above
sea level, the ship side wall penetration loss is bigger than at high receiving antenna height
(land BS antenna height). The simulated results are summarised in table 1.
Table 1. Simulation results of ship side wall penetration loss (dB) for land UE antenna at 1.5m
above sea level at distance of 10 km
Ship side wall modelling
Penetration loss (dB)
Metallic grid (Annex 2)
Metallic surface (Annex 3)
0,36
0,62
Based on the simulation results, it is proposed to use
i)
1 dB ship side wall penetration loss for the path from MCV BS/UE to land UE
ii)
0 dB ship side wall penetration loss for the path from MCV BS/UE to land BS.
4). Propagation model for the path Land BS to land UE
Free space as agreed.
5). Propagation model for the path MCV BS to land UE
a) Indoor MCV BS to land UE
JTG56 Sea model (Annex 1) + MCV wall penetration loss described in 3c)+3d)
b) outdoor MCV BS to land UE
JTG56 Sea model (Annex 1) + MCV wall penetration loss described in 3d)
6). Propagation model for the path MCV UE to land BS
a) Indoor MCV UE to land BS
JTG56 Sea model (Annex 1) + MCV wall penetration loss described in 3c)+3d)
b) outdoor MCV UE to land BS
JTG56 Sea model (Annex 1) + MCV wall penetration loss described in 3d)
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2.
Proposal
The proposed models are illustrated in figure 1 and summarised in table 2.
Table 2: Proposed propagation models
Nb
Path
Model
1
Indoor MCV BS to indoor MCV C-model (BP=15 m)
MS
2
Outdoor MCV BS to Outdoor C-model (BP=15 m)
MCV MS
3
Indoor MCV BS to Outdoor MCV C-model (BP=15 m)+11 dB (=6 dB)
MS
Sensitivity analysis: WPL=5, 10, 15, 20, 25 dB
4
Land BS to Land MS
Free Space
5
Outdoor MCV BS to Land MS
JTG56 Sea model+1 dB
6
Indoor MCV BS to Land MS
JTG56 Sea model+11 dB (=6 dB)+1 dB
Sensitivity analysis: WPL=5, 10, 15, 20, 25 dB
7
Outdoor MCV MS to Land BS
JTG56 Sea model
8
Indoor MCV MS to Land BS
JTG56 Sea model+11 dB (=6 dB)
Sensitivity analysis: WPL=5, 10, 15, 20, 25 dB
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Annex 1. Sea model (JTG56 Sea pathloss curves)
ITU-R P1546 contains land propagation curves and sea pathloss curves. The P1546 model
implemented in Seamcat is with the land propagation curves. JTG56 model is mainly P1546
model for large distance, in order to simulate the sea propagation, JTG56 model with Sea
pathloss curves was developed as plug-in in Seamcat.
The comparison between JTG56 sea model, ITU-R P1546 land model, and Free Space model
is plotted in figure A.1.
Figure A.1. Propagation model comparison
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Annex 2. Method of Moments (MoM) simulation results
In order to evaluate the attenuation of the ship’s side for the signal from the UE to the Land the
comparison of the results with model of the ship’s side and without it are prepared in the MoM
software. The UE Tx antenna was assumed as vertical dipole operating on frequency 2,6 GHz.
In Figures 2.1 and 2.2 the model of the ships’ side, location of the Tx antenna and area of
calculation are presented.
Fig. 2.1 Model of the ship’s side and location of the TX antenna (MCV UE)
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Fig. 2.2 Zoom of the model of the ship’s side (all parts are metallic, including board
(floor)). Ship’s side 1,2 m height, Tx antenna: 1,5 m height.
The area under consideration was horizontal surface located 10 m below ships’ side and with 10
km distance in direction to the land with 50 m width.
In figures 2.3 and 2.4 there is presented results of calculations in case of Tx source only and
with presence of the ship’s side respectively.
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Fig. 2.3 Results of the prediction of the field strength in the area of consideration – UE
Tx only
Fig. 2.4 Results of the prediction of the field strength in the area of consideration – in
the presence of the model of the ship’s side (all parts are metallic, including board
(floor)).
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The difference of the results of calculation have been calculated in order to evaluate the
attenuation level caused by the ship’s side. The results are presented in Fidures 2.5, 2.6 and
2,7 for the area up to 100m, up to 1 km and up to 10km respectively. Only positive difference
(attenuation given by the ship’s side) are presented.
Fig. 2.5 Results of the prediction of the attenuation given by the ship’s side (in dB, right
axix) for the distance up to 100 m (left axix).
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Fig. 2.6 Results of the prediction of the attenuation given by the ship’s side (in dB) for
the distance up to 1km.
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Fig. 2.7 Results of the prediction of the attenuation given by the ship’s side (in dB) for
the distance up to 10 km.
The results up to 100 m gives highest attenuation of the ship’s side but they have no practical
importance. The most important are differences on the higher distances. If attenuation on the
distances from 100 m to 10 km are considered than the highest level of attenuation is 0,36dB
(5,923mV/m - 5,683mV/m).
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Annex 3. Method of Moments (MoM) simulation results – ship’s side as metallic surface
In Figure 3.1 there is presented the model of the ship’s side as a full metallic surface. All
dimensions and distances are as in Annex 2.
Fig. 3.1 Zoom of the model of the ship’s side (the ship’s side is full metallic). Ship’s side
1,2 m height, Tx antenna: 1,5 m height.
The difference of the electric field strength for the Tx UE only and for the presence of the ship’s
side as a full metallic surface are present in Figures 3.2, 3.3 and 3.4 (as it was presented in
Annex 2).
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.
Fig. 3.2 Results of the prediction of the attenuation given by the ship’s side (in dB, right
axix) for the distance up to 100 m (left axix).
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Fig. 3.3 Results of the prediction of the attenuation given by the ship’s side (in dB, right
axix) for the distance up to 1 km (left axix).
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Fig. 3.4 Results of the prediction of the attenuation given by the ship’s side (in dB, right
axix) for the distance up to 10 km (left axix).
The results up to 50 m gives highest attenuation of the ship’s side but they have no practical
importance. The most important are differences on the higher distances. If attenuation on the
distances from 100 m to 10 km are considered than the highest level of attenuation is 0,62dB
(6,236mV/m - 5,804mV/m).
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Annex 4. MoM simulation results – on the area of possible location of Land BS
In Figure 4.1 there is presented the model of the ship’s side with MCV UE and the area,
perpendicular to the ground/sea in which BS antennas may be expected. The distance between
MCV Tx and Land BS Rx was assumed 12 NM and the considered area cover Land BS
antenna height up to 630 m above sea level.
In Figure 4.2 there is presented the zoom of the ship’s side and the UE Tx (dipole) in which
there is visible that the UE Tx is placed slightly not symmetrical to the model of the ship’s side.
Figure 4.1. Model of the ship’s side, MCV UE Tx antenna and are of possible
location of the Land BS (12 NM (≈22,3 km) from the ship)
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Figure 4.2. Modelo f the EU Tx over ship’s board – the slight non-symmetry of the
position of the EU Tx is visible
The difference of the electric field strength for the Tx UE only and for the presence of the ship’s
side is presented in Figures 4.3 (ship’s side made of metallic rods) and Figure 4.4 (ship’s side
as a full metallic surface).
.
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Fig. 4.3 Results of the prediction of the attenuation given by the ship’s side made of
metallic rods.
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Fig. 4.4 Results of the prediction of the attenuation given by the ship’s side as a full
metallic surface. .
The maximum attenuation given by the ship’s side on the area of the expected presence of the
Land BS in the 12 NM distance is:
 0,28dB (0,0279mV/m - 0,0270mV/m) – for the ship’s side made of metallic rods
 0,65dB (0,0279mV/m - 0,0259mV/m) – for the ship’s side as a full metallic surface.
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