## 6 Model Result
### Multi-Hop LoRaWAN Scenarios
When the payload is 20 bytes, the ToA is decreased to 71.9 ms, so the maximum number of transmitted packets increases to 500 packets/h. For temperature sensors, there is no traffic limitation for the different payload sizes (20-30-51 bytes). The pressure sensors in the first scenario network exceed the limit at device 306, whereas the second and third achieve it at device 308, as shown in Figure 9b. Due to the higher sample rate of the pressure sensors compared to the temperature sensor, the payload size must be 20 bytes or less to avoid more throughput, as we see in Figure 9. Thus, using a low payload size can solve the aforementioned issues in multi-hop scenarios and help avoid network congestion. Furthermore, that will allow the LoRaWAN network to accommodate more sensors. In terms of energy consumption analysis, both transmitted and received energy were considered, as well as the number of bytes and LoRaWAN configurations (SF = 7, CR = 1, BW = 125 kHz, payload = 20 bytes). We tested various transmission powers and selected the best in energy consumption (TP = 2 dbm). When the TP and SF increase, the ToA increases, which means more energy is needed for transmission. Equation (11) was used. Table 5 presents the energy test parameters. Figure 8: Generated packets per day for temperature sensors in different multi-hop scenarios for 88.6 km and 443 devices. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sensor Type** & **Temperature Sensor** & **Pressure Sensor** \\ \hline No. Packets (packet/day) & 3 & 24 \\ \hline Experiment Duration & 1-day & \\ \hline Packet Size & 35 bytes & \\ \hline LoRaWAN Parameters & SF = 7, CR = 1, BW = 125 kHz, Payload = 20 bytes \\ \hline Duty Cycle & 1\% & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The parameters of energy consumption experiments for the multi-hop scenarios. Figures 10 and 11 show the energy consumption/bytes for two sensor types within three multi-hop scenarios. The test uses previous LoRaWAN configurations (packet size = 35 bytes (15 bytes header and 20 bytes payload), SF = 7, BW = 125 kHz, CR = 1, TP = 2 dbm) and tests the energy of 50 devices. In the temperature sensor, the energy is high in the first scenario and lower in the third. For example, device 40 consumes 800 MJ in the first scenario and approximately 100 MJ in the third scenario. This means that the devices use more energy to cooperate in communication and send packets. Also, the energy consumption results show that pressure sensors demand more energy than temperature sensors. The second scenario decreased the transmission energy consumption by 44%, while the third scenario decreased it by 59%. We can conclude that the network architecture and the coordination of data transmission have a great impact on energy consumption. The hop ranges affect the performance metrics like throughput and energy consumption. The first scenario achieved more throughput than the others; however, that increased data traffic by 38%. Energy consumption was lower by 44% in the second scenario and 59% in the third. Figure 9: Generated packets per day for pressure sensors in different multi-hop scenarios for 88.6 km and 443 devices: (**a**) the generated packets for all 443 devices, (**b**) the generated packets for 20 devices as an example (devices from 300 to 320) to display the maximum number of packets transmitted in each multi-hop scenario (exceeding the maximum packets at device 306 in the first scenario and at device 308 in the second and third scenario). As Figure 9b shows, setting the payload to 51 bytes achieved higher throughput; however, it exceeded the traffic limit and could not accommodate all sensors. To solve that, the number of sensors must be decreased. When payload = 20 bytes, the network could accommodate more sensors, which increased the scalability. Additionally, packets with larger sizes consumed more energy. Because our case study has medium traffic demand and energy consumption is a priority, setting the payload to 20 bytes fits our network requirements.