Low-cost Radio Channel Sounder for the ISM 2.4 GHz Band

Due to the ISM 2.4 GHz-band is becoming more and more crowded, some wireless communication services in this band could be seriously affected. Because of that, this paper proposes a reliable and networked system able to monitor in real-time or near-real-time, the radio channel health based on a channel sounding technique. The results here presented are divided into two groups: large-scale and small-scale. In the first one, a Close-In Breakpoint Path Loss model is fitted to data empirically obtained for the 2.4 GHz-band in indoor and outdoor scenarios. In the second group, two parameters are introduced to determine the influence of multipath in the radio link. One of them, named as the Line of Sight (LoS) Factor, determines how strong the direct path is in relation to the set non-direct propagation paths. The second one, named as the Channel Health Indicator (CHI), determines the availability of the radio link by using a percentage scale.