Effect of Wind on Foliage Obstructed Line-of-Sight Channel at 2.5 GHz

Investigations of Foliage Effect on Modern Wireless Communication Systems: A Review

“…It is reported that the standard deviation of the attenuation variation about the mean does increase as the wind speed increases, and for 2 GHz radio service in rural areas, a fade margin of 3.4 dB should be allowed. Later, fading characteristics of a 6 MHz channel centered at 2.545 GHz were reported by Pelet et al [47] with a variation of wind speed. They indicated that wind impinging on the trees at velocities as low as 15 km/h can cause significant fading.…”

“…Recently, the relationship between the Rician K factor and averaged wind speed is found to be linear at 1.9 GHz as reported in [54]. From these works [46][47][48][49][50][51][52][53][54], it can be observed that the windinduced motion of the foliage medium can vary the tree shadowing effect temporally, and the temporal variation of the shadowing can be statistically modeled. Rician K factor is usually used to characterize the temporal shadowing effect.…”

“…While the change in the humidity of the foliage medium can vary the dielectric parameters (conductivity and permittivity) of the trees and then influence the signal propagation. From the open literature, large amount of the empirical works have contributed to the investigations of the wind induced temporal power variation [19,[46][47][48][49][50][51][52][53][54] and humidity increased foliage attenuation [55,56]. They will be discussed in the following respectively.…”

“…Naz et al [48] conducted an investigation of wind effect on different foliated states at a much higher frequency up to 29.5 GHz as compared to the work in [46,47]. They found that trees with green foliage (in summer) produce less variation as compared to trees with yellow and dehydrated foliage (in fall), and dense trees cause attenuation but do not produce much variation.…”

“…Recently, Pelet et al [47] observed that there was an additional attenuation of about 5 dB across a cluster of poplar trees at 2.5 GHz when there was a rain fall at a rate of 6 mm/hr. From these works [15,47], and [55,56], it can be found that higher humidity can increase the propagation attenuation.…”