A very fast ray-based field strength prediction tool for urban microcells operating in the UHF-band

Many microcell models in literature apply ray tracing or ray launching techniques, having however the disadvantage of consuming too much computer-running time for engineering applications. The number of propagation paths has to be minimised and the path finding algorithms have to be simplified in order to achieve a much faster average field strength prediction. This is possible particularly for dense urban microcells, where, in essence, street canyons can be assumed. On behalf of the Research Centre of Deutsche Telekom a prediction tool was developed based on this assumption and on two semi-empirical models to determine the propagation loss through these street canyons. To extract the empirical propagation parameters and to verify the fast prediction tool, comprehensive simultaneous measurements at 919 and 1873 MHz were carried out in many different streets and in two urban microcells of approximately 600/spl times/800 m.