Free-space path loss (FSPL) is the weakening of a wireless signal as it propagates through unobstructed space. It limits how far a receiver can distinguish and decode the signal. section 18.1.1
Treat FSPL as a wireless LAN coverage constraint rather than the only cause of attenuation. Frequency, transmitter power, antenna type, distance, and environmental conditions affect usable range; reflection, diffraction, scattering, and absorption can further alter the signal. section 18.1.1 section 18.5
Operational implications include:
- Expect typical indoor coverage of up to 150 feet (46 meters), while outdoor coverage can exceed 300 feet (91 meters); actual distances vary substantially. section 18.1.1
- Recognize that a receiver becomes unable to decode a signal when its strength falls below the level needed to distinguish it from background noise. section 18.1.1 section 18.5
