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?