Fig. 15

Four representative clustering realizations. In this figure, four representative clustering realizations depending on UEs distribution are highlighted. Figure 13a (realization i.), GPS and UWB methods give us a hotspot where the one given by UWB signals has a smaller radius than the one given by the GPS. Figure 13b (realization ii.), both clustering methods detect this hotspot, its radius is much smaller using UWB method than GPS and also seems to be more dense. In Fig. 13c (realization iii.) and in Fig. 13d (realization iv.), by using GPS for hotspot detection only the predefined hotspot is detected by the method whereas UWB detects the two sub-hotspots. In Fig. 13d, UEs close to the predefined hotspot are taken into account by the UWB method and are included into the final detection