propagation loss models lab 4 engr. mehran mamonai
TRANSCRIPT
Propagation loss modelsLab 4
Engr. Mehran Mamonai
Terrain, Clutter, Morphology
Traffic Load Prediction
BS Performance Parameters
Cell site 、 Propagation model 、 Antenna system
Model correction
System Simulation
Meet requirements of the operator?
Link Budget
Output reports
PN Planning
RF Interference Analysis
Y N
Source ZTE ‘CDMA network planning’
Network planning process
Mobile BTSCable loss
Antenna gain
Path loss
Antenna gain
Cable loss
Margin
Link budget model
Calculate all the gains and losses you have over a linkSee figure on next slide
Determine allowable maximum path lossDetermine optimal cell radius
This is part of a simplified link budget calculator for GSM.
The figure on the left shows the calculator for the maximum allowable path loss
The figure below shows the calculator for optimal cell size
Okumura’s modelThe model has been developed from an extensive
series of field trials, which were undertaken in and around Tokyo under the following conditions:Frequencies from 100 MHz to 3 GHzDistances from l km to 100 kmDifferent terrain conditions: urban, suburban, rural
with various degree of undulationEffective base antenna height from 30 m to l000 mVehicular antenna height from lm to l0 mOther factors such as the orientation of streets and
the presence of mixed land-sea paths.
The basis of the method is to determine the free-space path loss at a receiver located dkm, from a transmitter and then add that value to the median attenuation, Aμ, in urban area over quasi-smooth terrain with a base station effective antenna height, hte, of 200 m and a mobile antenna height, hre, of 3 m. The free space path loss at a frequency, say, fMHz can be determined using the following equation:
where GT and GR are the gain of the transmitting and receiving antennas, respectively
Correction factors are introduced to account for propagation path characteristics
Hata modelIn an attempt to make the Okumura model easy to
apply, Hata established empirical mathematical relationships to describe the graphical information given by Okumura
Hata's formulation is limited to certain ranges of input parameters and is applicable over quasi-smooth terrain
Restrictions of Hata-Okumura modelBS height: 200 mMS height: 100 mFrequency: 500 – 1500 MHzDistance between MS & BS: 1 - 20 Km
Variables
150 - 1000 MHz
1500 – 2000 MHz
c1 69.55 46.3
c2 26.16 33.9
)(log)}(log55.69.44{)()(log82.13)(log 1010101021 dhhahfccL bmbHU
f : Carrier frequency (MHz)
hb : Base station antenna height 30 m ≤ hb ≤ 200 m
hm : Mobile station antenna height
a(hm) : Mobile antenna gain function
c1 & c2 are correction factors
)8.010log56.1()7.0log1.1()( cmcm fhfha
Hata Urban
Variables
150 - 1000 MHz
1500 – 2000 MHz
c1 69.55 46.3
c2 26.16 33.9
mbmbHU CdhhahfccL )(log)}(log55.69.44{)()(log82.13)(log 1010101021
f : Carrier frequency (MHz)
hb : Base station antenna height 30 m ≤ hb ≤ 200 m
hm : Mobile station antenna height
a(hm) : Mobile antenna gain function
c1 & c2 are correction factors
Cm : 3 dB
Hata Dense urban
97.4)}75.11({log2.3)( 210 mm hha
Hata model for Sub-urban
Hata model for Quasi-open rural
Hata model for Open
Remember! Propagation models will never give accurate path lossIn fact it is only a prediction for the path loss
4.5)}({log2 22810 f
HUHS LL
94.35)(log33.18)}({log78.4 102
10 ffLL HUQO
94.40)(log33.18)}({log78.4 102
10 ffLL HUO
Today’s Lab taskMake function files for Hata’s model
There would be five function filesUse these files to find the Loss incurred by the
radio signal under the following circumstancesOperating frequency: 910 MHzDistance between BS & MS: 2 KmBS height: 45 mMS height: 1.5 m
Attach the function files in the handout!See next slide for more…
Using these codes, plot the following graph