plex cross-section permittivity of 10 j, a tree measured. In each BS site, the array was always directed trunk radius of 10 cm, and a density of 1000 trees per towards a street canyon to measure the received powers along hectare [ToLa04], it is observed that attenuation expressed the canyon and the perpendicular streets. Measured streets in dB decreases linearly with increasing distance, the in- have different widths within approximately 20 to 30 m. coherent component contributing over the coherent one. Empirical path-loss models were derived from mea- For example, at 100 m the incoherent intensity adds 10 dB surement data by using the least square error method. over the coherent attenuation. Globally, the coherent at- For the LoS case, seven streets were measured, a path- tenuation, in dB, as a function of distance, is given by 0.21d, loss exponent of 2.34 and a standard deviation of 2.6 dB whereas the total attenuation is obtained as 0.11d. being obtained. For the NLoS one, nine perpendicular Indoor measurements at 2.45 and 5.25 GHz, and streets were measured. It was observed that the path-loss a system bandwidth of 100 MHz, carried out at exponents are within 1.6 to 2.9, with a mean value of Elektrobit premises in Oulu during night time in an 2.34, the standard deviation is within 1.9 to 5.6 dB, with unpopulated office are presented in [LZMJ05]. By using a mean value of 3.1 dB. linear regression of the measured data the path loss was Field prediction in vegetated residential environments is evaluated, Lp = 48.1 + 17.3 log(d) and Lp = 3.3 + 52.1 not easily accomplished by standard path-loss prediction log(d) being obtained at 5.25 GHz, for the LoS and models [Corr01]. The electromagnetic fields of radio NLoS cases, respectively. At 2.45 GHz, Lp = 42.7 + 16.4 waves propagating through a tree canopy can be decom- log(d) and Lp = 10.8 + 45.4 log(d), was evaluated. posed into mean (coherent) and diffuse (incoherent) A method for modelling path loss inside office build- components. At low frequencies, the diffuse co