g_|F(v) (6.32) Figure 6.8 shows the equivalent representation of knife-edge diffraction geometry which is used to compute the effective height of the knife edge obstacle h oeff and the radial distance d between the knife edge obstacle and the transmitter Tx, the radial distance d, between the knife edge obstacle and the receiver R as given in Equations (6.33) to (6.39). 5G Wireless Communication System in Healthcare Informatics hoeff=(hobt-hox-h) (htx-hrx) FIGURE 6.8 The equivalent geometric representation of the knife-edge diffraction model. To calculate the effective height hoeff of the knife edge obstacle, we first find the value of h'. tan (2) (6.33) W1+W2 tan (9) (6.34) On comparing Equation (6.33) and (6.34), we get (6.35) Now the radial distances d and d2 are calculated using Figure 6.8 and Equation (6.35) here, we get 2=v(h) (6.36) (6.37) Now, effective height of the knife edge obstacle is calculated using Equation (6.35) holl= (6.38) (6.39) In Giovaneli [11], a Fresnel-Kirchhoff knife edge diffraction approach is used to compute path loss over multiple obstacles. Absolute path loss is defined in this UTD-PO and FKE Models for Path Loss Prediction approach as the sum of the path losses determined from each individual obstacle with regard to Tx and Rx, without considering the impact of other obstacles. 6.3 RESULTS AND DISCUSSION To validate UTD-PO and FKE approaches, four different terrain scenarios were chosen from the literature. MATLAB software is used to run all of the simulations. In Figures 6.9, 6.10, 6.11 and 6.12 the results obtained for the UTD-PO and the FKE approaches are compared with the measurement data observed at 25 GHz frequency vertically polarized [22]. For each of the following terrain scenarios, a simulation was run to estimate path loss for both approaches when the receiver moved vertically from NLOS (shadowed region) to LOS (illuminated region). Figure 6.9 shows the prediction of path loss over a single knife edge obstacle where transmitter T of height h is 58.33 2 above the obstacle