## 4 Model Results  
In order to test both aforementioned models, a number of IoT services was assumed. Their characteristic parameters are shown in Table 4:  
For LoRaWAN, it was assumed that different spreading factors are employed in different cell ranges. Additionally, three 125 kHz channels are assumed to be employed within the cell. In all scenarios, the packet preamble was considered to consist of 8 bits, and the packet header included 13 bits. The tests assumed unacknowledged mode uplink transmission by Class A devices following the methodology of [2].  
Figure 2 illustrates the ToA values for the different scenarios. It can be seen that Scenario 3 results in larger ToA values due to its more demanding requirements in terms of the required application bytes to be transmitted per unit time (50 bytes per 5 min). This is also shown in Figure 3, which depicts the throughput variation versus the cell range for the different scenarios. Finally, Figure 4 depicts the maximum number of devices for each of the cell range zones for the three scenarios. Here it is interesting to observe that the highest device capacity is achieved for Scenario 2 (sending 20 bytes per 10 min), followed by Scenario 3 (sending 50 bytes per 10 min), leaving last Scenario 1 (sending 1 byte every 30 s). It can be seen that Scenarios 1 and 2 have much different performance results even though the actual byte transmission rates are the same (1.33 bytes/s). This is due to the fact that the duty cycle of Scenario 1 is much higher than that of Scenario 2. The Duty Cycle (DC) is expressed as:  
\[DC=\frac{ToA}{ToA+T_{OFF}} \tag{12}\]  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Service Parameter** & **Scenario 1** & **Scenario 2** & **Scenario 3** \\  & **PL = 1 B @ 30 s** & **PL = 20 B @ 10 min** & **PL = 50 B @ 5 min** \\ \hline Application data size (bytes) & 1 & 20 & 50 \\ Packet transmission & 30 s & 10 min & 5 min \\ period & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: IoT Service parameters.  
Figure 1: Coverage and capacity assessment methodology.  
Figure 5 depicts the various DC values for Scenarios 1, 2, and 3. It can be seen that Scenario 1 has the highest duty cycle values, approaching the maximum theoretic allowable limit of 1% [2].  
Figure 4: LoRaWAN device capacity for different application payloads and packet rates.  
Figure 3: LoRaWAN device throughput for different application payloads and packet rates.  
Figure 2: LoRaWAN Time over the Air (ToA) for different application payloads and packet rates.  
Considering the NB-IoT model, results have been obtained for similar metrics, assuming a PRB of 180 kHz utilizing for the uplink a subcarrier spacing equal to 15 kHz and an RU that consists of 3 SC-FDMA subcarriers and 8 slots, including 168 REs.  
Figure 6 depicts the ToA values for Scenarios 1, 2, and 3. The difference among the various cell ranges is due to the increase in repetitions from one up to four, which inevitably increases the ToA for each packet transmission. Scenario 3 has the highest ToA values and also the highest throughput values, as shown in Figure 7. However, Scenario 2 is shown to achieve the highest device capacity per cell as depicted in Figure 8.  
Figure 5: Duty cycle values for different application payloads, packet rates, and ranges.  
Figure 6: NB-IoT Time over the Air (ToA) for different application payloads and packet rates.  
Figure 7: NB-IoT device throughput for different application payloads and packet rates.