Abstract—Radio signal propagation prediction plays an essential role in planning of modern broadband mobile radio

role in planning of modern broadband mobile radio networks. While the less accurate statistical models predict only the path loss, the more precise ray tracing techniques enable computation of additional parameters, e.g. the mean delay and the delay spread, which are significant for the 4G network planning. The existing ray tracing methods are mainly applied in the indoor and narrow urban environments. In this paper, an open-source solution for propagation prediction with a ray tracing method in the open urban and rural areas is presented. The emphasis is on the implementation of a computationally efficient procedure, which is divided into two separately optimized problems, tessellation and ray tracing. Ray tracing is implemented by applying an improved shooting and bouncing ray (SBR) approach. The efficiency of the implementation is analysed in terms of computational complexity and results accuracy. The simulation results show that by applying a tessellation optimization technique the processing time is reduced up to 50%. The improved SBR ray tracing approach has been incorporated in the existing open source radio planning tool GRASS-RaPlaT.