In the friis equation, the reference distance is 1m at the log distance path loss.

Then the formula would be:

$$P_r = P_tA_rA_t(\lambda/(4\pi d))^\alpha$$

where $d$ is distance between terminals, $P_r$ is received power, $P_t$ is transmission power, $A_r, A_t$ are the rx, tx antenna gains, respectively, and $\lambda$ is wavelength.

It seems that the path loss exponent $\alpha$ is not mentioned.

But I haven't seen a case where this $\alpha$ isn't 2.

Is this $\alpha$ always 2 in the friis equation?

And can the simulation environment be used even if this $\alpha$ is not 2?

In the friis equation, the reference distance is 1m at the log distance path loss.

Then the formula would be:

$$P_r = P_tA_rA_t(\lambda/(4\pi))^2 /d^\alpha$$

where $d$ is distance between terminals, $P_r$ is received power, $P_t$ is transmission power, $A_r, A_t$ are the rx, tx antenna gains, respectively, and $\lambda$ is wavelength.

It seems that the path loss exponent $\alpha$ is not mentioned.

But I haven't seen a case where this $\alpha$ isn't 2.

Is this $\alpha$ always 2 in the friis equation?

And can the simulation environment be used even if this $\alpha$ is not 2?