The model

The Lee model is formally expressed as:

${\displaystyle L\;=\;L_{0}\;+\;\gamma \log d\;-10\log {F_{A}}}$

where,

L = The median path loss. Unit: decibel (dB)

L₀ = The reference path loss along 1 km. Unit: decibel (dB)

${\displaystyle \gamma \;}$ = The slope of the path loss curve. Unit: decibels per decade

d = The distance on which the path loss is to be calculated.

F_A = Adjustment factor.

Calculation of reference path loss

The reference path loss is usually computed along a 1 km or 1 mile link. Any other suitable length of path can be chosen based on the applications.

${\displaystyle L_{0}\;=\;G_{B}\;+\;G_{M}\;+\;20\;(\log \lambda \;-\;\log d)\;-\;22}$

where,

G_B = Base station antenna gain. Unit: decibel with respect to isotropic antenna (dBi)

${\displaystyle \lambda }$ = Wavelength. Unit: meter (m).

G_M = Mobile station antenna gain. Unit: decibel with respect to isotropic antenna (dBi).

Calculation of adjustment factors

The adjustment factor is calculated as:

${\displaystyle F_{A}\;=\;F_{BH}\;F_{BG}\;F_{MH}\;F_{MG}\;F_{F}}$

where,

F_BH = Base station antenna height correction factor.

F_BG = Base station antenna gain correction factor.

F_MH = Mobile station antenna height correction factor.

F_MG = Mobile station antenna gain correction factor.

F_F = Frequency correction factor

Base-station antenna height correction factor

${\displaystyle F_{BH}\;=\;\left(\;{\frac {h_{B}}{30.48}}\;\right)^{2}}$

where,

h_B = Base-station antenna height. Unit: meter (m).

or

${\displaystyle F_{BH}\;=\;\left(\;{\frac {h_{B}}{100}}\;\right)^{2}}$

where,

h_B = Base-station antenna height. Unit: foot (ft).

Base-station antenna gain correction factor

${\displaystyle F_{BG}\;=\;{\frac {G_{B}}{4}}}$

where,

G_B = Base-station antenna gain. Unit: decibel with respect to half wave dipole antenna (dBd)

Mobile-station antenna height correction factor

${\displaystyle F_{MH}\;=\;{\begin{cases}\;\;{\frac {h_{M}}{3}}\;\;\;\;{\mbox{ if, }}h_{M}>3\\{\Big (}{\frac {h_{M}}{3}}{\Big )}^{2}{\mbox{ if, }}h_{M}\leq 3\end{cases}}}$

where,

h_M = Mobile-station antenna height. Unit: meter(m).

Mobile-antenna gain correction factor

${\displaystyle F_{MG}\;=\;G_{M}}$

where,

G_M = Mobile-station antenna gain. Unit: Decibel with respect to half wave dipole antenna (dBd).

Frequency correction factor

${\displaystyle F_{F}\;=\;{\big (}{\frac {f}{900}}{\big )}^{-n}{\mbox{ for }}2<n<3}$

where,

f = Frequency. Unit: megahertz (MHz)