Log-distance path loss model

The log-distance path loss model is a radio propagation model that predicts the path loss a signal encounters inside a building or densely populated areas over long distance.

While the log-distance model is suitable for longer distances, the short-distance path loss model is often used for indoor environments or very short outdoor distances.

It's simpler and assumes a more direct line-of-sight propagation.

is the average multiplicative gain at the reference distance

is a stochastic process that reflects flat fading.

In case of only slow fading (shadowing), it may have log-normal distribution with parameter

This can be convenient, because power is proportional to the square of amplitude.

In many cases, exponential distributions are computationally convenient and allow direct closed-form calculations in many more situations than a Rayleigh (or even a Gaussian).

in dB have shown the following values for a number of indoor wave propagation cases.