orming both reflected and transmitted power mea- [CoLA03] and [LoCo05] a multi-environment predic- surements on different kinds of walls with directive an- tion tool based on a 2.5 ray-launching technique for tennas. An IEEE 802.11b transmission system between outdoor and for outdoor-indoor propagation and a 3D- two Power Controls (PCs) was used. In order to separate RT for indoor propagation is presented (see also Sub- the desired reflected or transmitted signal from spurious section 4.7.3.4). An optimised indoor database format signals coming from surrounding objects, a time-domain was adopted to speed up indoor prediction without sig- resolution method using the Pseudo-Noise (PN) sequences nificant loss in accuracy. Only the main structures that of the IEEE 802.11 was adopted. The electromagnetic significantly infer on the propagation mechanisms (typi- characteristics were then determined by a 'feedback' it- cally the floor surfaces, the facades and the concrete erative technique where the Electro-Magnetic (EM) pa- partitions) are used in the computation of the multipath rameters in the input to a 3D RT (see Subsection 4.7.3.4) ray trajectories, the light partitions are only taken into were varied until the measured value was reproduced with sufficient accuracy (see Figure 4.7-7). Mixed database handling Table 4.7-2 Frequency dependent conductivity o (f) of EMC shielded MRTo-rooms for RT simulations. A variety of radio communication systems such as DAB and DVB, 3G public networks and Wireless Local Area Frequency (MHz) o (S/m) Networks (WLANs) must coexist in urban and suburban environments. To assure high-quality in-building cover- age for the different systems in different environments (indoor, microcellular, macrocellular, etc.), or to control the limits and interferences between the various cell layers in a complex network, deterministic simulation tools are required in conjunction with appropriate multi- environment database handling techniques. In [LoCo02a], Propagation modelling and channel characterisa