1)Under the link budget formulla:
path loss= TX power + all gain in link – all loss in link – RX sensitivity.
2)the shadow fading yielded by the building or other obstacles in propagation environment & its distrubuted as log normal.
Thus if the path loss made global mean slope. the variation in this slope up & down called as local mean or log normal fading(shadow fading).
shadow fading differ from urban to suburban to rural as the obstacles cosentration changed.
geo climatic factor ? i know the rain can have a serious influence on the radio propagation (up to 3 to 6 dB), so it is smart to take in to account the “average amount of rain drop in the country” for your pathloss computation.
Vertical / Horizontal diversity :
horizontal is more efficient (less separation distance needed for the same amount of Rx Gain), but sometimes the antenna support cannot stand horizontal separation mounting. Therefore, in such cases, you have to use V-diversity.