Attenuation is a reduction of signal strength during transmission, such as when sending data collected through automated monitoring. Attenuation is represented in decibels (dB), which is ten times the logarithm of the signal power at a particular input divided by the signal power at an output of a specified medium. When signal power decreases to relatively low values, the receiving 802.11.4 radio will likely encounter bit errors when decoding the signal. This problem worsens when significant RF interference is present. The occurrence of bit errors causes the receiving 802.11.4 station to refrain from sending an acknowledgement to the source station. After a short period of time, the sending station will retransmit the frame. In the worst case, signal power loss due to attenuation becomes so low that the system loses connectivity to the network gateway.This white paper defines wireless signal loss in terms of the attenuation in both signal frequency and range and provides the reader with attenuation formulas, RF site survey guidelines for understanding the behavior of radio waves within a facility before installing a wireless network, and RF interference impact and avoidancetechniques including causes of RF signal fading.