<Dl> <Dd> d ≈ 2 ⋅ k ⋅ R ⋅ h (\ displaystyle d \ approx (\ sqrt (2 \ cdot k \ cdot R \ cdot h))) </Dd> </Dl> <Dd> d ≈ 2 ⋅ k ⋅ R ⋅ h (\ displaystyle d \ approx (\ sqrt (2 \ cdot k \ cdot R \ cdot h))) </Dd> <P> k> 1 means geometrically reduced bulge and a longer service range . On the other hand, k <1 means a shorter service range . </P> <P> Under normal weather conditions, k is usually chosen to be ​ ⁄ . That means that the maximum service range increases by 15% . </P>

Long distance communication between two point on earth is achieved by