What is a primary challenge of Non-Line of Sight propagation?

The primary challenge of Non-Line of Sight (NLOS) propagation is its susceptibility to interference from buildings and other obstacles. In NLOS situations, the radio waves do not have a direct path between the transmitter and receiver, which can lead to various types of interference. When these signals encounter structures such as buildings, they can be reflected, refracted, or absorbed, which can degrade signal quality and reliability. This atmospheric condition is crucial in urban environments where buildings are densely packed and can obstruct signal paths. Effective communication systems must account for this interference to maintain strong signal propagation in situations where direct line of sight may not be achievable.