## 8 Performance Comparison with Related Protocols  
In this section, we firstly address the improvement ratios of the proposed AFB-GPSR compared to the conventional routing protocols AODV and GPSR with fixed periodic beaconing. In summary, in the first scenario of varying network size (i.e., small network scalability up to 50 nodes), it is found that the PDR is improved by nearly 10%, 5% and 5% on average compared to GPSR-2s, GPSR-1s and AODV, respectively. Additionally, throughput percentage of AFB-GPSR also increases by 15%, 5% and 5% on average, respectively. Moreover, the speed-variant scenario shows the improvement in ratios of 17%, 8% and 13% on average and improvement in throughput of 35%, 13% and 23% on average compared with GPSR-2s, GPSR-1s and AODV, respectively). However, it is noticed that E2 ED is approximately the same in the conventional GPSR-1 and GPSR-2 when there is an increase in the node density or node speed as well. Meanwhile, AODV has registered a higher delay than AFB-GPSR and the standard GPSRs, because AODV usually takes a longer time to establish its routes. For the third scenario, the proposed AFB-GPSR also outperforms GPSR-2s and GPSR-1s when the transmission power varies from 1 mw to 5 mw. Higher transmission power means higher network reliability, and lower transmission power leads to low node connectivity. As a result, the AFB strategy can provide more optimal routing performance when the transmission power decreases. Furthermore, this AFB strategy can reduce the routing cost of NRL by 14% and 35% compared with GPSR-2s and GPSR-1s, respectively. On the other hand, Table 4 summarizes the average results of the three experimental scenarios as follows. In the first scenario, with different network sizes (i.e., number of nodes varies up to 50 nodes), it is found that the PDR achieves 67% on average in AFB-GPSR compared to GPSR-2s, GPSR-1s, and AODV (57%, 62%, and 62%, respectively). In addition, the throughput value in AFB-GPSR is 9519 bps on average compared to (8243, 9015, & 9017 bps) in GPSR-2s, GPSR-1s and AODV, respectively. Moreover, in the speed-variant scenario, the AFB-GPSR has registered the highest PDR of 75% on average, compared to the GPSR-2s, GPSR-1s, and AODV, (58%, 67%, and \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Routing Protocol** & \multicolumn{3}{c}{**Experimental Scenario (1)**} \\ \hline  & **PDR\%** & **E2E Delay** & **Throughput** \\ \cline{2-4} GPSR-2s & \(57\%\) & 0.193 & 8243 \\ \cline{2-4} GPSR-1s & 62\% & 0.187 & 9015 \\ AODV & 62\% & 0.308 & 9017 \\ \hline AFB-GPSR & 67\% & 0.187 & 9519 \\ \hline  & \multicolumn{3}{c}{**Experimental Scenario (2)**} \\ \hline  & **PDR\%** & **E2E Delay** & **Throughput** \\ \cline{2-4} GPSR-2s & 58\% & 0.25 & 8276 \\ \cline{2-4} GPSR-1s & 67\% & 0.27 & 9924 \\ \cline{2-4} AODV & 62\% & 0.5 & 9056 \\ \hline AFB-GPSR & 75\% & 0.29 & 11,161 \\ \hline  & \multicolumn{3}{c}{**Experimental Scenario (3)**} \\ \hline  & **PDR\%** & **NRL** & **Throughput** \\ \cline{2-4} GPSR-2s & 73\% & 21 & 10,568 \\ \cline{2-4} GPSR-1s & 81\% & 27 & 11,733 \\ \cline{2-4} AODV & --- & --- & --- \\ \hline AFB-GPSR & 86\% & 18 & 12,462 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The average performance of three experimental scenarios. 62%), respectively. And, AFB-GPSR has the highest average throughput of 11,161 bps in various speed settings. For the third scenario, when the transmission power varies from 1 mw to 5 mw, at fixed speed 10 mps and 50 nodes, AFB-GPS outperforms in its PDR up to 86% on average compared to the GPSR-2s and GPSR-1s (both achieve 73% & 81%), respectively. However, this AFB strategy can effectively reduce the NRL routing cost to achieve 18 on average compared with GPSR-2s and GPSR-1s; meanwhile both GPSRs reach higher routing costs, 21 and 27, respectively. On the other hand, to verify the robustness and effectiveness of the proposed AFB-GPSR protocol, Table 5 showcases different comparative performances with other recent adaptive-beaconing-based GPSR protocols.