For example, here let’s assume the height of obstacle is 10m (h), and obstacle is 2km (d1) far away from one outdoor AP while 8km (d2) far away from another outdoor AP. Then r would be 14.142m. The ideal and best mounting height should be 24.142m (h + r). But this height may not be easy to get. Considering there is 40% toleration (5.657m, r * 0.4), the minimum mounting height can be 18.485m (h + r –toleration).