# A Comprehensive Evaluation Algorithm of Multi-Point Relay Based on Link-State Awareness for UANETs
## 4 Simulation and Results
### Analysis of Results  
To evaluate the quality of the routing protocol design, this paper considers two aspects: data transmission accuracy and transmission speed. It selects the following four indicators to assess whether the optimized routing protocol can better meet the network performance requirements in the set task scenario. 1. Packet Delivery Rate  
Figure 7a illustrates the packet delivery rate for five protocols under varying speeds, while Figure 7b depicts the growth rate in packet delivery rate for CEL-OLSR, PM-OLSR, ML-OLSR, and LD-OLSR when compared to OLSR. Notably, CEL-OLSR demonstrates the highest packet delivery rate. When compared to PM-OLSR, CEL-OLSR exhibits an average increase in packet delivery rate of 2.56%. Compared to ML-OLSR, this increase is 6.89%. Furthermore, when compared to LD-OLSR and OLSR, CEL-OLSR registers an average improvement of 11.11% and 22.04%, respectively. In our simulation, we categorize the drone flight phase into three stages based on speed: low speed, mid-low speed, and mid-high speed. Table 2 presents the packet delivery rate for the comparison protocols at different speed stages. It is evident that the packet delivery rate decreases as speed increases. Importantly, CEL-OLSR exhibits the smallest decrease. The probability of link disruption rises with node speed, leading to an increase in the number of lost packets. Figure 7: The comparison of packet delivery rate. (**a**) Trends in packet delivery rate for various protocols with changing speeds; (**b**) growth rate of packet delivery rate for various protocols compared to OLSR at different speeds. In the environment of ad hoc networks, the stability between links is a crucial factor in ensuring smooth packet delivery. With the increase in node mobility, the stability of links faces challenges because the relative positions of nodes become more variable, leading to continuous changes in network topology. This dynamic variation forces routing protocols to update frequently to adapt to the new network state, which may lead to the occurrence of routing loops, outdated routing information, and potential packet loss before reaching the destination. Additionally, as link disruption events increase, ensuring successful packet delivery becomes more difficult, often requiring multiple retransmissions. This not only exacerbates network load pressure but also, in cases of repeated unsuccessful retransmissions, may result in eventual packet discarding. In summary, the acceleration of node mobility inevitably exacerbates network dynamics, leading to a series of link and routing issues that may negatively impact successful packet delivery. 2. Average End-to-End Delay  
As depicted in Figure 8a, within the node speed range of 10 m/s to 50 m/s, CEL-OLSR exhibits a maximum average end-to-end delay of approximately 11.07 ms, characterized by minimal fluctuations. In comparison to PM-OLSR, CEL-OLSR demonstrates a reduction in average end-to-end delay by 4.66 ms. Compared to ML-OLSR, this reduction amounts to 9.03 ms. Furthermore, when contrasted with LD-OLSR and the standard OLSR, CEL-OLSR showcases an overall decrease of 12.98 ms and 24.82 ms, respectively. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Speed Stage** & **Speed** & **CEL-OLSR** & **PM-OLSR** & **ML-OLSR** & **LD-OLSR** & **OLSR** \\ \hline \multirow{3}{*}{Low speed stage: 10 m/s\(\sim\)20 m/s} & 10 m/s & 81\% & 78\% & 75\% & 72\% & 62\% \\  & 15 m/s & 79\% & 76\% & 73\% & 69\% & 60\% \\  & 20 m/s & 78\% & 76\% & 72\% & 68\% & 59\% \\ \hline \multirow{3}{*}{Mid low-speed stage: 25 m/s\(\sim\)35 m/s} & 25 m/s & 79\% & 75\% & 72\% & 68\% & 56\% \\  & 30 m/s & 77\% & 74\% & 71\% & 67\% & 55\% \\  & 35 m/s & 76\% & 74\% & 69\% & 65\% & 54\% \\ \hline \multirow{3}{*}{Mid high-speed stage: 40 m/s\(\sim\)50 m/s} & 40 m/s & 75\% & 73\% & 68\% & 63\% & 52\% \\  & 45 m/s & 72\% & 70\% & 64\% & 59\% & 47\% \\ \cline{1-1}  & 50 m/s & 71\% & 69\% & 62\% & 57\% & 45\% \\ \hline \hline \end{tabular}
\end{table}