-11.3 -19.0 -10.3 station Hotspot railway -19.2 station Picocell highway with metal support structures in München this ratio was 1.8, 5.2 and 17.2 GHz respectively, in 600 MHz of -10.3 dB, Table 4.7-15. Other environments, such as bandwidth for good temporal resolution, using a pro- urban microcell streets and squares, an indoor auditorium prietary stepped-frequency correlation sounder. People lobby, and a highway bridge picocell, showed power ratios walking around in the room acted as moving scatterers. in between. In the environments with relatively large The effect on static channels was clear from the broad- amounts of DMC power, the estimator tended to find ening of the otherwise very narrow Doppler spectrum and fewer specular components than in environments with the changes in the impulse response. Also, the amplitude relatively high power in the specular components. variations over time are better noticeable than phase The observation by Trautwein et al. that diffusely fluctuations, as many multipath components, stemming scattered power cannot be neglected in a number of en- from for instance the constructional part of the building, vironments, was made by others within COST 273 too, do not change at all. The effect of moving scatterers was i.e. they experienced that there seems to be a ceiling as also distinctly different from time-variant channel be- regards the amount of power that can be captured by high- haviour due to receiver movement. Therefore, Katten- resolution estimators. Wyne et al. retrieved in an outdoor- bach and Früchting conclude that channels with moving to-indoor environment a worst case of 60% with 40 scatterers should be modelled differently from those only multipath components, with a median around 85% and showing time variance due to receiver movement. For the most probable extraction efficiency of around 90% modelling temporal correlations, the moving scatterers [WAKE04]. Haneda et al. found slightly lower figures can be ignored irrespective of their number, but they indoors, betwe