Hybrid ray optical models for the penetration of radio waves into enclosed spaces

With the growing interest for broadband mobile services in 3rd generation mobile communication networks, the investigation of radio transmission into vehicles and buildings is getting more important. Models for the propagation into vehicles and buildings enable the calculation of the field strength or received power inside these objects. The inner structure of the vehicles (e.g. metal parts) and buildings (inner walls, furniture) as well as the surroundings (other vehicles, buildings) must be considered, and also different construction materials must be taken into account. A deterministic ray tracing approach has been developed, enabling the computation of the transition from an urban scenario to an indoor scenario and vice versa, thus allowing a very accurate computation of the field strength or received power inside vehicles or buildings. Due to the ray tracing technique, the approach can also be utilized to evaluate wideband properties of the mobile radio channel by computing its impulse response. In order to validate such propagation models, measurements inside and outside a building were made.