The desired height of the transmitting and receiving antenna in telecommunications is determined by the so-called Fresnel zones. The energy propagated between the antennas creates a spindle shape in space, the width of which is maximum halfway between them. Ideally, the antenna placement points should be selected so that no objects that attenuate radio waves can be located within the Fresnel zone (tree crowns, house roofs, hills, earth's surface). Otherwise, part of the energy emitted towards the receiving antenna will be lost.
There are many online Fresnel zone calculators that allow you to calculate the spindle cross-section at a given point on the path between the antennas. This information, together with the height of the obstacle we are concerned about, allows us to determine how high the mast we should place the radio link to avoid energy losses.