# Design and Implementation of a Mixed IoT LPWAN Network Architecture
## 5 Case Study and Testing Environment
It can be noted that Sigfox improves the reception rate, reaching in some cases a reception rate of 100%. However, it is the solutions based on LoRaWAN and LoRa-Sigfox Gateway that ones that achieve a reception rate of 100% in every analyzed building. In the case of LoRaWAN, possibly the main reason is due to the fact that its base station is placed closer to the water-meter than the Sigfox, which current location is determined the operator of the area. Figure 23: Number of samples received in the case of a building in which the reception rate is ranged within 25%-75%. (**a**) In the 169 MHz ISM band, 121 samples were received (50.4%). (**b**) Reception rate with the Sigfox prototype of 90.8% (**c**) Reception rate with the LoRaWAN device of 100% (**d**) Reception rate with the LoRa-Sigfox Gateway device of 100%. Figure 24 shows a graph with the samples received during the same period of 10 days (240 samples) by each of the different acquisition devices placed in one of the buildings associated with one of the so-called 'acceptable' water-meters (reception rate higher than 75%). This water-meter is located in the entrance box to a residential house (chalet), similar to the one showed in Figure 20c. The X axis indicates the number of the sample associated with the time at which it was acquired (values between 1 and 240 for the 10-day evaluation period with a sampling time of one hour) and the Y axis indicates the value (litres) measured by the water meter and transmitted by the acquisition device. This figure shows that the samples received with the device operating at the 169 MHz ISM Band, instead of the expected 240, is now 217, which means a reception rate of 90.4%. In this case, the three tested prototypes achieve a 100% reception-rate. Table 3 summarizes the results of the study case for each of the different buildings with acquiring devices attached to water-meters placed on locations where reception rate in the 169 MHz ISM band is higher than 75%. As said before, the three tested prototypes achieve a 100% reception-rate, which clearly confirms that if there are no shadow zones in coverage, the IoT technologies improve the performance of classic solutions such as the 169 MHz ISM Band used by the water distributor. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Building** & **169 MHz ISM** & **Sigfox** & **LoRaWAN** & **LoRa-Sigfox Gateway** \\ \hline B06 & 121 (50.4\%) & 218 (90.8\%) & 240 (100\%) & 240 (100\%) \\ B07 & 148 (61.7\%) & 229 (95.4\%) & 240 (100\%) & 240 (100\%) \\ B08 & 170 (70.8\%) & 240 (100\%) & 240 (100\%) & 240 (100\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Reception rates over a period of 10 days (240 samples) with each of the different systems tested in a water-meter with a percentage of received samples ranged within 25%–75% over expected in the 169 MHz ISM band. Figure 24: Number of samples received in the case of a building in which a reception rate higher than 75%. (**a**) In the 169 MHz ISM band, 217 samples were received (90.4%). (**b**) Reception rate with the Sigfox prototype of 100%. (**c**) Reception rate with the LoRaWan device of 100%. (**d**) Reception rate with the LoRa-Sigfox Gateway device of 100%. To check system performance and ensure load capacity, the whole set has been subjected to stress testing above the common operating conditions. Instead of sending data once an hour, all the devices have been configured to send data every 10 min, the minimum allowed interval due to duty cycle regulation in the 868 ISM band. In a period of 72 h, it supposes 432 frames per device and a total of 14256 frames, equivalent to 99 days sending data once an hour. It allows check hardware devices reliability and system behaviour in a longer operational period. Reception rates can be seen in Table 4, very close to those obtained in the 10 days period study case. Increasing the number of devices and so on the network load, is not a problem for Sigfox and LoRaWAN technologies due are able to manage \(10^{6}\) and \(10^{4}\) devices per base station respectively.