In this paper, a large number of studies of the effect of the foliage on single or lines of trees on modern wireless communication systems are reviewed. The paper is focused on the experimental works mainly done for commercial applications such as cellular communication and high speed point-to-point fixed link at the microwave and millimeter wave frequencies. For this review study, the development of the foliage loss prediction methods and the factors influencing the tree-induced shadowing effect are highlighted. In view of current research work in this area, some possible future works are proposed to improve the performance of modern wireless communication systems with the effect of foliage.
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