Is the path loss exponent $\alpha$ is always 2 in friis equation model?

Path loss exponent is not always equal to 2, only in the free space scenario is this true. In general the received power Pr is proportional to d−α, where α is somewhere around 2-6 depending on the situation. The choice of the path loss exponent should match the scenario you're trying to simulate.

1. What is path loss exponent?
2. What is the typical value of path loss exponent?
3. Which one is the Friis equation?
4. What is Friis free space propagation model?

What is path loss exponent?

The path loss exponent (PLE) is a parameter indicating the rate at which the received signal strength (RSS) decreases with distance, and its value depends on the specific propagation environment.

What is the typical value of path loss exponent?

Typical values of path–loss exponents range between 1.5 and 5.

Which one is the Friis equation?

The Friis transmission equation (Equation 10.14. 2) gives the power delivered to a conjugate-matched receiver in response to a distant transmitter, assuming co-polarized antennas and free space conditions.

What is Friis free space propagation model?

Friis free space propagation model is used to model the line-of-sight (LOS) path loss incurred in a free space environment, devoid of any objects that create absorption, diffraction, reflections, or any other characteristic-altering phenomenon to a radiated wave.