The Lee model for point-to-point mode is a radio propagation model that operates around 900 MHz. Built as two different modes, this model includes an adjustment factor that can be adjusted to make the model more flexible to different regions of propagation.[1]
This model is suitable for using in data collected in a specific area for point-to-point links.
900 MHz band
The Lee model for point to point mode is formally expressed as:
L=L0+\gammaglogd-10\left(log{FA}-2log\left(
| HET | |
| 30 |
\right)\right)
where,
L = The median path loss. Unit: decibel (dB).
L0 = The reference path loss along 1 km. Unit: decibel (dB).
\gamma
d = The distance on which the path loss is to be calculated. Unit: kilometer (km).
FA = Adjustment factor
HET = Effective height of terrain. Unit: meter (m).
The reference path loss is usually computed along a 1 km or 1 mi link. Any other suitable length of path can be chosen based on the applications.
L0=GB+GM+20\left(logλ-logd\right)-22
where,
GB = Base station antenna gain. Unit: decibel with respect to isotropic antenna (dBi).
λ
GM = Mobile station antenna gain. Unit: decibel with respect to isotropic antenna (dBi).
The adjustment factor is calculated as:
FA=FBHFBGFMHFMGFF
where,
FBH = Base station antenna height correction factor
FBG = Base station antenna gain correction factor
FMH = Mobile station antenna height correction factor
FMG = Mobile station antenna gain correction factor
FF = Frequency correction factor
F1=\left(
| hB | |
| 30.48 |
\right)2
where,
hB = Base station antenna height. Unit: meter.
F2=
| GB | |
| 4 |
where,
GB = Base station antenna gain. Unit: decibel with respect to half-wave dipole (dBd).
F3=\begin{cases}
| hM | |
| 3 |
if,hM\le3\ (
| hM | |
| 3 |
)2 if,hM>3\end{cases}
where,
hM = Mobile station antenna height. Unit: meter.
F4=GM
where,
GM = Mobile station antenna gain. Unit: decibel with respect to half wave dipole antenna (dBd).
F5=\left(
| f | |
| 900 |
\right)-nfor2<n<3
where,
f = Frequency. Unit: megahertz (MHz).
This is computed in the following way: