[IEEE 1997 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, PACRIM. 10 Years Networking the Pacific Rim, 1987-1997 - Victoria, BC, Canada (20-22 Aug. 1997)] 1997 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, PACRIM. 10 Years Networking the Pacific Rim, 1987-1997 - Propagation in urban environments based on asymptotic methods and ray tracing techniques