Radio Networking Help Tools

Egli & Free Space Calculator

This first calculation is used for propagation loss. This value tells how much the signal strength is decreased due to the distance between the transmitter and the receiver. For this we use the Egli model. The Egli model is a simplified model that assumes "gently rolling terrain with average hill heights of approximately 50 feet (15 meters)". Because of this assumption, no terrain elevation data between the transmitter and receiver facilities is needed. Instead, the free-space propagation loss is adjusted for the height of the transmitter and receiver antennas above ground. As with many other propagation models, Egli is based on measured propagation paths and then reduced to mathematical model. In the case of Egli, the model consists of a single equation for the propagation loss.

The free space calculator shows the theoretical attenuation with no terrain considerations. Again, you can enter a value for Distance and see the Attenuation, or alternatively enter a value for Attenuation, to see the maximum Distance.