# LoRa, Zigbee and 5G Propagation and Transmission Performance in an Indoor Environment at 868 MHz
## 6 Conclusions  
This work was focused on the study of the propagation and performance aspect of NB, LoRa, Zigbee and 5G transmissions. For this purpose, indoor measurements were performed with four technologies in two NLOS situations at 868 MHz. Two different fitting models have been proposed for the measurements, the CI and the FI models. It has been observed that the CI model shows a behavior more associated with the physical propagation of the wave itself, while the FI model shows a better fit. It has also been shown that the CI model has disadvantages in the NLOS situation, while the FI model does not. The behavior of the RSSI parameter has been found to be very similar to that of the actual measured power. The four transmissions show very similar waveguide behavior in the NLOS-1 zone (\(n<2\)), while in the NLOS-2 zone, the transmissions attenuate more aggressively, with LoRa showing less attenuation in the NLOS-2 zone (\(\beta=4.59\)). This indicates that LoRa has a higher performance than the other technologies used in this work for indoor corridor environments. It has been observed that the BER of LoRa and Zigbee transmissions are strongly related to the distance, so it is also strongly related to the received power. That is to say, the BER is directly proportional to the distance and inversely proportional to the received power. By means of the FI models designed for each technology, the predicted power at a point has been correlated with the measured BER value, and power margins have been established for which a BER of 5% is exceeded. Some graphs have also been presented with which the values of the quality parameters, BER and SS-RSRQ, can be obtained by means of the measured power value and vice versa. Therefore, it is possible to predict, to some extent, quality parameters, such as BER and SS-RSRQ, by using measured power parameters, such as real power, RSSI power and SS-RSRP power. \begin{table}
\begin{tabular}{c c c c c} \hline  & **NB Power** & **LoRa RSSI** & **Zigbee RSSI** & **SS-RSRP** \\ \hline \hline
**LoRa BER (\textgreater{}5\%)** & \(-88\) dBm & \(-119\) dBm & Out of range & Out of range \\ \hline
**Zigbee BER (\textgreater{}5\%)** & \(-56\) dBm & \(-94\) dBm & \(-97\) dBm & \(-98\) dBm \\ \hline
**5G SS-RSRQ (\(\leftarrow\)\(-18\) dB)** & \(-81\) dBm & \(-114\) dBm & Out of range & Out of range \\ \hline \hline \end{tabular}
\end{table} 
Table 4: BER predictions from measurement. \begin{table}
\begin{tabular}{c c c c c} \hline  & **Power Example** & **LoRa BER** & **Zigbee BER** & **5G SS-RSRQ** \\ \hline
**Narrow band power** & \(-61\) dBm & \(0\) \% & \(86.93\) \% & \(-11.04\) dB \\ \hline
**LoRa RSSI** & \(-98\) dBm & \(0\) \% & \(86.67\) \% & \(-11.04\) dB \\ \hline
**Zigbee RSSI** & \(-91\) dBm & \(0\) \% & \(0\) \% & \(-12.14\) dB \\ \hline
**5G SS-RSRP** & \(-103\) dBm & \(3.33\) \% & \(100\)\% & \(-13\) dB \\ \hline \hline \end{tabular}
\end{table} 
Table 5: BER for examples of received power values for each technology. **Author Contributions:** Conceptualization, R.R.-E., J.-M.M.-G.-P. and L.J.-L.; Data curation, R.R.-E., J.-M.M.-G.-P. and L.J.-L.; Formal analysis, R.R.-E.; Funding acquisition, J.-M.M.-G.-P. and L.J.-L.; Investigation, R.R.-E.; Methodology, R.R.-E., J.-M.M.-G.-P. and L.J.-L.; Resources, R.R.-E., I.P.M.-A., A.S.-S., M.T.M.-I., A.M.-A., [PERSON]-M.M.-[PERSON]-P. and [PERSON]-[PERSON]; Software, R.R.-E.; Supervision, [PERSON]-[PERSON]-[PERSON]-P. and [PERSON]-[PERSON]; Validation, R.R.-E., [PERSON]-M.M.-[PERSON]-P. and [PERSON]-L.; Visualization, R.R.-E.; Writing--original draft, R.R.-E., I.P.M.-A., A.S.-S. and A.M.-A. ; Writing--review and editing, R.R.-E. All authors have read and agreed to the published version of the manuscript. **Funding:** This research was co-funded by Ministerio de Ciencia e Innovacion of the Spanish Government under the National Project PID2019-107885 GB-C33 and co-funded by MCIN/AEI/10.13039/501100011033. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable.