Simple tests to predict fading in tree obstructed MMDS channels

A wireless system such as MMDS (multipoint microwave distribution system) is a cost effective solution for service providers to extend their cable coverage to the immediate rural area. A MMDS extended cable system works well when there is clear line-of-sight to the head-end antenna. In near-line-of-sight transmission where a few foliated trees in the vicinity of the customer house partly block the line-of-sight, large and rapid signal fading can occur under windy conditions. This is due to the motion of the trunk and branches. The magnitude of the fading largely depends on the placement of the receive antenna. This paper provides two simple tests that predict the worst case fading when wind is present for a given placement of the receive antenna