ubsections, such as database sim- points where the field has to be evaluated. Simulations of plification studies, fast BL models, etc., several recent amplitude-delay profiles are performed at 60 GHz, the studies within COST 273 specifically dealt with the considered indoor environment being a small laboratory development of techniques aimed at decreasing compu- area (3.5 X 6.5 X 2.8 tation time and improving capabilities or performances of In order to validate the simulated results, measure- ray models. ments were performed in the 59-61 GHz frequency band with a network analyser. Both for simulations and mea- Speed-up techniques surements, the transmit and receive antennas were open In [HoWW03] a novel method for the acceleration of 3D ended waveguides. The measurement campaign consisted ray models is presented. As the database of the consid- of amplitude/phase measurements at 10 to 30 different ered urban topology remains the same during one or sampling points within four spots, chosen to illustrate more 'runs' and only the position of the TX or of the RX different types of channels (Line-of-Sight, LoS, Non- changes, most part of the rays remains unchanged: only Line-of-Sight, NLoS). Root Mean Square (RMS) delay the rays connecting terminals change. Therefore, a sort of spread values computed from simulated amplitude-delay 'database preprocessing' can be performed which only profiles and from measurement results are shown in depends on the particular topology. In a first step building Figure 4.7-12. For clarity, only rectangles containing the walls are divided into tiles and the edges into horizontal values obtained for all points in a given spot are shown in and vertical segments (see Figure 4.7-13). After this, the the figure, together with the mean value for each spot. Not visibility conditions between these different elements CHAPTER 4.7 Propagation modelling and channel characterisation measurements: the agreement is very good, comparable to what is obtained in [HoWW03]. In Figure 4.7.14 an example of pred