Shibuya Method for Computing Ten Knife Edge Diffraction Loss

Abstract

Shibuya multiple knife edge diffraction loss method is presented in this paper. The Shibuya method is used to compute the effective diffraction loss of ten multiple knife edge obstructions for a 900 MHz GSM network. Each of the ten obstructions gave rise to a virtual hop which resulted in a knife edge diffraction loss while the overall diffraction loss, according to the Shibuya method is the sum of the diffraction loss computed for each of the ten virtual hops. According to the results, the highest line of sight (LOS) clearance height of 8.480769 m and the highest diffraction parameter of 0.397783 occurred in virtual hop 6. On the other hand, the lowest line of sight (LOS) clearance height of 0.628571 m and the lowest diffraction parameter of 0.044447 occurred in virtual hop 9. Furthermore, the highest virtual hop diffraction loss of 9.30294 dB occurred in virtual hop 6 whereas the lowest virtual hop diffraction loss of 6.38736 dB occurred in virtual hop 9. In all, the overall effective diffraction loss for the 10 knife edge obstructions as computed by the Shibuya is 71.7973 dB.