# Railway Wireless Communications Channel Characterization
## 3 Characterization Tools  
The mentioned QoS parameters shall be measured in the proposed environment in order to characterize the communication channel. In fact, the mapping of the different QoS parameters and the corresponding impairments with the location is relevant information in order to know how the communication channel is and where the environment could affect it. Thus, the reason for possible degradation of the communication channel or even the lack of coverage can be known thanks to the mapping of location-impairment. For that, three tools available in the market are compared and shown in Table 1: R&S products for drive test software, Pilot Pioneer from DingLicom, and RantCell.  
As Table 1 shows, these tools can measure different technologies and parameters in any environment. Nevertheless, they are not a user-customizable tool, technologies are fixed, and there is no chance to integrate another current of future technologies in the system. Additionally, the system hardware set-up--more particularly, the antennas--cannot be  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **R\&S**[13] & **DingLicom [14]** & **RantCell [15]** \\ \hline \multicolumn{3}{c}{5G NR} \\ \multicolumn{3}{c}{Nb-IoT/Cat-NB1} \\ GSM/EDGE & 5G \\ WCDMA/HSPA+ & 4.5G & 5G \\ CDMA2000 & 4G & 4G \\ WiMAX & 3G & 3G \\ LTE & 2G & 2G \\ LTE-M & LTE-IoT \\ TETRA & \multicolumn{3}{c}{WLAN} \\ \hline
**Environment** & Any environment & Any environment & Any environment \\ \hline \multicolumn{3}{c}{RF (SINR, RSRQ, RSRP)} \\ \multicolumn{3}{c}{RSF (SINR, RSRQ, RSRP)} \\ \multicolumn{3}{c}{QoS testing capabilities:} \\ \multicolumn{3}{c}{QoS coverage measurements,} \\ \multicolumn{3}{c}{interference identification,} \\ \multicolumn{3}{c}{performance measurements,} \\ \multicolumn{3}{c}{quality analysis in mobile networks} \\ \multicolumn{3}{c}{Bandwidth,} \\ \multicolumn{3}{c}{Location} \\ \hline \multicolumn{3}{c}{ROMES4} \\ \multicolumn{3}{c}{**Testing and**} \\ \multicolumn{3}{c}{**post-processing/visualizing**} \\ \multicolumn{3}{c}{**from the user point of view**} \\ \multicolumn{3}{c}{Additional devices/drivers depending on**} \\ \multicolumn{3}{c}{the use case to be tested**} \\ \hline
**User-customizable** & - & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 1: Tool comparison.  
changed, reducing the capabilities of measuring the impact of the different antennas during the measurements and avoiding the use of higher gain antennas.  
Furthermore, some of these tools need the purchase of more than one product of the same company instead of having an all-in-one device or one service for the whole test performance.  
Moreover, these tools can be employed in any environment as they are not railway-specific, so they would not consider the railway specific track with the corresponding stations.  
Regarding how to obtain and visualize the results, the DingLicom tool requires another product for the post-processing and visualizing task. Moreover, if the goal is to measure different environments at the same moment, R&S needs multiple products to reach the same goal present in the R&S products.  
As well, some of these tools can measure specific impairments such as maximum data rate with a location, but not in a continuous mode; they are rather individual tests in separated moments, and therefore, separated locations. The aim of having a continuous geolocated impairment is not covered by any of these tools.  
In conclusion, these tools do not completely fulfill the purpose of the railway migration task. Because of these reasons, an innovative tool called Channel Characterization Tool (CCT) is proposed.