# Insights into the Issue of Deploying a Private LoRaWAN
## 4 Experimental and Analytical Results
### Performance Evaluation
#### 4.1.2 Indoor Coverage and Signal Propagation  
We measured the public and private network performance in the campus building (see Figure 3). Specifically, we estimated the RSSI, which provides information about signal propagation, coverage, sensitivity, and attenuation of materials. Each value is an arithmetic mean of 20 measurements. These values were obtained for each building part and the floor. Together, they were used to create a heat map of the RSSI (the outdoor calibration values are in Table 3--scenario (ii), private \(-84\) dBm and public \(-108\) dBm). Figures 7 and 8 provide results for both networks on the seventh floor. The public network RSSI ranged from \(-97\) to \(-119\) dBm. The private network RSSI ranged from \(-70\) to \(-107\) dBm with expected best results in the building E (the building with our gateway on the roof). The mean loss rate was \(<\)0.1% for both types of network; this allows using both deployments in critical applications requiring \(>\)99.9 availability [64]. However, we observed a higher loss rate (7%) under the gateway (approx. 3 m under a gateway with the reinforced concrete roof in between, the building E--the place with highest RSSI \(-70\) dBm, see Figure 7). Although the private network offers higher RSSI than the public network, the public operator offers sufficient service to cover indoor conditions in this case. Based on the authors' market knowledge, the \(868\) MHz traffic will probably become denser in the future due to the growing number of sensors. Therefore, we can expect that the selected channels in the frequency plan will gain a higher noise level and the \(-119\) dBm might become a border value for the sensitivity because the interferences might cause a signal strength degradation of over 20 dB for the LoRaWAN technology [62]. Figures 9 and 10 provide results for both networks on the fifth floor. The private network signal strength was in the range of \(-86\) to \(-115\) dBm with a strength loss of \(>\)10 dB in most of the building, except for the building A, where the degradation was minimal due to the line-of-sight between the building and the gateway. The loss rate in the private network grows to 1%. Moreover, the higher loss rate under the gateway in the building E was not observed. On the other hand, the public network signal strength ranged from \(-98\) to \(-119\) dBm. The min/max values are the same as on the previous floor, but the heat-map shows a rapid decrease of the mean RSSI (Figure 10). Further, the average loss rate on the fifth floor grew to 7% in the public network, which allows using it in non-critical indications, metering, and other applications requiring (\(>\)90%) availability. On this floor, the private network starts to show a slight advantage. Figures 11 and 12 provide results for both networks on the third floor. The signal strength for the private network was in the range of \(-97\) to \(-115\) dBm. The signal strength dropped again by about 5 to 10 dB and the loss rate increased to 4%. However, the network parameters were stable, and the communication service was available throughout the \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Scenario** & **RSSI (dBm)** & **SNR (dB)** & **LR (\%)** \\ \hline Public—default plan (i) & \(-125\) & \(-18.36\) & \(43\) \\ \hline Public—default plan (ii) & \(-97\) & \(-2.05\) & \(3\) \\ \hline Private—default plan (i) & \(-96\) & \(0.01\) & \(21\) \\ \hline Private—extended plan (ii) & \(-70\) & \(14.90\) & \(1\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Effect of the plan on performance (arithmetic means). whole building. An availability of 96% allows using it in most of the metering applications which require (\(>\)90%) availability [64]. Further, the range of RSSI for public networks was in the range of \(-\)116 dBm to no signal (N/O). The signal strength also decreased by another 10 dB. Compared with the calibration value, the attenuation is already more than 30 dB, which can be considered as a deep(er) indoor condition.