TerrainLOS is a propagation model (a propagation model is an algorithm that simulates real world wireless communication) that uses terrain to determine the success of a transmission.

Propagation models tend to be overly simple (If you are within 100m of my location we can communicate) or overly complex (Calculate every reflection, refraction, and diffraction to determine if we can communicate. TerrainLOS offers an outdoor propagation model that is computationally simple.

TerrainLOS is currently implemented in Cooja, a wireless network simulator for the ContikiOS operating system.