Overview of Presentation

1. Propagation Modeling in Urban EnvironmentsDr. Saul A. TorricoComsearchSenior Technical Consultant

2. Overview of Presentation • Objective • Basic Principles of Diffraction • Building Database • Propagation Over Buildings • Results • Conclusions

3. Objective • Point-to-Point systems. • Assess the path loss in an Urban environment from the Interference point of view. • Propagation over buildings. • Simplified representation of buildings. • Which diffraction techniques are used in the calculations?

4. Basic Principles of Diffraction • Diffracting Regions. • Diffraction Techniques • Physical Optics • Uniform Theory of Diffraction. • Wedge Diffraction. • NSMA Recommendation.

5. Diffracting Regions

9. Building Database • Point-to-Point building profile. • Influence of roof shapes. • Replacing buildings by absorbing screens. • Average description of building heights and street widths.

10. Buildings vs. Absorbing Screens

11. Average Building Heights hHub hB hR d

12. Top View - Buildings • 1st-Fresnel vs. Buildings RCVR XMTR

13. Propagation Over Buildings • Multiple screen diffraction – Physical Optics. • First and Last Obstacle – Uniform Theory of Diffraction (90o Dielectric Wedge)

14. 1st. Example 1st Fresnel Zone HXMTR HRCVR

15. Results

16. 2nd. Example 1st Fresnel Zone HXMTR HRCVR

17. Results

18. Results

19. Results

20. Conclusion • Frequency congestion is increasing rapidly in urban markets. • Clearing cases based on building blockage may allow increased density of frequency assignments. • Path loss calculations in Urban environments.