6.2 LogDistancePropagationLossModel
6.2.1 Model reference
From source: Urban Propagation Measurements and Statistical Path Loss Model at 3.5 GHz, Marcus C. Walden, Frank J. Rowsell
Given equation:
| | PL{dBm} = PL(d0) + 10*n*log(d/d0) + Xs
PL(1) from friis at 2.4GHz: 40.045997dBm
PL{dBm} = 10*log(.050357/Pr) = 40.045997 + 10*n*log(d) + Xg
Pr = .050357/(10^((40.045997 + 10*n*log(d) + Xg)/10))
bandwidth = 2.2*10^7
m_noiseFigure = 5.01187
no interference, so SNR = Pr/4.41361e-13W
taking Xg to be constant at 0 to match ns-3 output:
Distance :: Pr :: SNR
10 4.98265e-9 11289.3
20 6.22831e-10 1411.16
40 7.78539e-11 176.407
60 2.30678e-11 52.2652
80 9.73173e-12 22.0494
100 4.98265e-12 11.2893
200 6.22831e-13 1.41116
500 3.98612e-14 .090314
1000 4.98265e-15 .011289
|
6.2.2 Validation test
Test program available in ns-3 at src/devices/wifi/propagation-loss-model-test-suite.cc
Taken at default settings (exponent = 3, reference loss = 46.6777, 802.11b at 2.4GHz)
| | Distance :: Pr
10 4.98265e-9
20 6.22831e-10
40 7.78539e-11
80 9.73173e-12
|
6.2.3 Discussion
As can be seen, the received power outputted from the model, and the power computed from the source’s equation are identical. The test suite tests
the expected value to the most significant digit of the input expected value.
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