An empirical based path loss model with tree density effects for 1.8 GHz mobile communications using fuzzy regression

Abstract

Upper-and lower-bound path loss models in the forests are presented in this paper. We performed measurements in different forest densities at a frequency of 1.8 GHz with base station antenna height in a range of 3, 4, and 5 m above ground while the receiving antenna height was fixed at 1.8 m above ground. The forest was classified into different density areas namely, high-, medium-, low-density and grass area. We proposed upper-and-lower bounds path loss models which depend on max and min values of sample path loss data. It does not depend on sample size. This makes our models limit path loss within the boundary lines while the confidence interval of standard regression is dependent on the sample size. Comparison between the fuzzy regression model and conventional regression model shown that the proposed models agree with measured data within the bounds while the conventional regression models provide over estimations at their upper-and lower-bounds. The proposed models will be useful for the local wireless network and micro-cell design of mobile communication systems in forests.