# Combined Use of LoRaWAN Medium Access Control Protocols for IoT Applications
## 6 Performance Evaluation
### Assessment in Different Scenarios and Channel Configurations
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multirow{2}{*}{**MAC Protocol**} & \multicolumn{2}{c}{**Type of**} & \multirow{2}{*}{**PLR- Case L**} & \multirow{2}{*}{**PLR-Case M**} & \multirow{2}{*}{**PLR-Case H**} \\  & & **End-Devices** & & & \\ \hline \multirow{4}{*}{SHC} & Pure ALOHA & Stationary & 6.08\% & 10.50\% & 18.68\% \\  & & Mobile & 5.49\% & 9.73\% & 18.07\% \\ \cline{2-6}  & LBT AFA & Stationary & 5.09\% & 8.78\% & 16.14\% \\  & & Mobile & 4.30\% & 7.38\% & 14.32\% \\ \hline \multirow{4}{*}{SPC Configuration A} & Pure ALOHA & Stationary & 6.68\% & 10.27\% & 18.46\% \\  & & Mobile & 5.69\% & 9.30\% & 18.25\% \\ \cline{2-6}  & LBT AFA & Stationary & 3.88\% & 7.62\% & 15.93\% \\  & & Mobile & 3.59\% & 6.60\% & 13.77\% \\ \hline \multirow{4}{*}{SPC Configuration B} & Pure ALOHA & Stationary & 7.07\% & 11.70\% & 21.79\% \\  & & Mobile & 6.62\% & 11.11\% & 21.34\% \\ \cline{2-6}  & LBT AFA & Stationary & 3.31\% & 6.15\% & 12.92\% \\ \cline{1-1}  & & Mobile & 3.18\% & 5.29\% & 10.96\% \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Average PLR under different traffic conditions. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multirow{2}{*}{**MAC Protocol**} & \multicolumn{2}{c}{**Type of**} & \multirow{2}{*}{**PLR- Case L**} & \multirow{2}{*}{**PLR-Case M**} & \multirow{2}{*}{**PLR-Case H**} \\  & & **End-Devices** & & & \\ \hline \multirow{2}{*}{SHC} & \multirow{2}{*}{LBT AFA} & Stationary & 1.69\% & 4.44\% & 6.90\% \\  & & Mobile & 1.61\% & 4.62\% & 6.97\% \\ \hline \multirow{2}{*}{SPC Configuration A} & SPC & \multirow{2}{*}{LBT AFA} & Stationary & 1.74\% & 4.41\% & 6.91\% \\  & & Mobile & 1.83\% & 4.37\% & 7.00\% \\ \hline \multirow{2}{*}{SPC Configuration B} & SPC & \multirow{2}{*}{LBT AFA} & Stationary & 1.33\% & 4.36\% & 6.95\% \\  & & Mobile & 1.35\% & 4.31\% & 6.93\% \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Average PDR under different traffic conditions (LBT AFA only). As it was expected, the highest maximum e2 eDelay values are experienced in Case H, i.e., when the end-devices generate the highest number of messages. In fact, in this case, for both the MAC protocols under consideration, multiple messages can be enqueued in the MAC layer queue, and therefore, the e2 eDelay also includes the time spent by the message in the MAC layer queue waiting for being transmitted. Moreover, in Case H, the probability that the channels are found to be busy with LBT AFA is higher than in the other cases. As a result, sometimes, the end-devices reach the maximum allowed number of backoffs before a successful transmission, and therefore, they experience the highest maximum e2 eDelay values. Finally, Table 11 shows the energy-consumption ratio per transmission in all the scenarios assessed. As expected, the energy consumption of the end-devices that use LBT AFA is higher than that of the end-devices that use Pure ALOHA, as LBT AFA involves one or more CCAs before transmission. Furthermore, the highest \(ECR^{tx}\) values are obtained in Case H, i.e., under the highest workload. In fact, in this case, the end-devices that adopt LBT AFA run a higher number of CCAs due to multiple (unsuccessful) transmission attempts on busy channels. As shown in Table 11, the \(ECR^{tx}\) values obtained in the SHC scenario are higher than those obtained in the two configurations of the SPC scenario. This is because in the SHC scenario, LBT AFA can use all the available channels, and therefore, a higher number of CCAs can be run before performing a backoff. However, the end-devices that use Pure ALOHA and those that use LBT AFA compete for the same channels. Consequently, the  
channels are sensed as busy multiple times, and therefore, the higher number of CCAs implies a higher energy consumption.