Which type of radio signal propagation is typically used in urban environments with obstructions?

The type of radio signal propagation that is typically used in urban environments with obstructions is Non-Line of Sight. In these settings, buildings, trees, and other obstructions can block direct paths between the transmitter and receiver, which makes Line of Sight communication ineffective.

Non-Line of Sight propagation relies on signals that can reflect, diffract, or scatter around obstacles, allowing communication even when there isn't a clear line of sight. This is particularly important in urban environments where the landscape is dense and varied. The ability of signals to navigate through or around obstructions enables reliable communication over shorter distances, which is essential for effective radio operation in such areas.

In contrast, Line of Sight signals require a direct path between transmitter and receiver, which can be challenging in cities. Ground Wave propagation is more effective over longer distances but is limited to lower frequencies and typically does not perform well in urban settings with many obstructions. Sky Wave transmission is more suited for long-distance communication and is not typically used in urban environments that rely on Non-Line of Sight methods for reliability.