# Research of Security Routing Protocol for UAV Communication Network Based on AODV
## 4 Simulation and Numerical Results
Secondly, the performance of ISAODV is compared with AODV and SAODV after adding malicious nodes. Figures 4 and 5 show the PDR and throughput of UAV communication network under normal conditions, respectively. As can be seen from the figure, the performance of ISAODV and SAODV routing protocols in the packet delivery rate and throughput is very close to the AODV routing protocol. This shows that the ISAODV and SAODV routing protocols inherit the characteristics of the AODV routing protocol and maintain the route discovery and route maintenance capabilities of the AODV routing protocol to the greatest extent. With the increase of the moving speed of UAVs, the link state changes frequently, and the rate of processing packets decreases, which leads to the decrease of packet delivery rate and throughput. Therefore, the faster the UAV moves, the more unstable the communication quality is. In this paper, the common malicious node attack model is implemented in the simulation experiment. After receiving the RREQ message that does not take itself as the destination node, the malicious node will immediately reply to RREP and set the hop number to 1. The source node chooses the path of the malicious node for data transmission, and all packets passing through the malicious node will be discarded. In the simulation experiment, five malicious nodes are set up. Figures 6 and 7 show the PDR and throughput of UAV communication network after adding malicious nodes, respectively. As can be seen from the figure, the packet delivery rate and throughput of AODV routing protocol without the security guarantee are much lower than those under normal conditions when there are malicious nodes in the network, and the performance is far lower than ISAODV and SAODV routing protocols. Due to the added security guarantee, the packet delivery rate and throughput of SAODV and ISAODV routing protocols have not decreased significantly with the  
Figure 4: The packet delivery radio (PDR) under normal conditions. addition of malicious nodes. Therefore, SAODV and ISAODV routing protocols can effectively resist malicious node attacks, and the effect of ISAODV is better than SAODV, with higher security. Figure 8 shows the end-to-end delay of UAV communication network under normal conditions. It can be seen from the figure that the delay of AODV is the lowest no matter what mobile rate the  
Figure 5: The throughput under normal conditions. Figure 6: The PDR after adding malicious nodes. Figure 7: The throughput after adding malicious nodes. node is. The delay of SAODV is higher than that of ISAODV. This is because the complexity of the algorithm is related to the packet delay. The AODV routing protocol does not consider the security factor, so the complexity of the algorithm is relatively low and the delay is the lowest. Since each node on the active path of the SAODV protocol must be authenticated and signed based on the CA certificate, the complexity of information transmission is much higher than that of ISAODV based on the elliptic curve cryptosystem. The end-to-end delays of the three protocols increase as the speed of the UAV moves. This is because when the link state changes frequently, the chance of signal collision and collision increases, the proportion of route failure increases sharply, and the route reconstruction process suddenly becomes frequent, thereby increasing the end-to-end delay. Figure 9 shows the end-to-end delay of UAV communication network after adding malicious nodes. As can be seen from the figure, after adding malicious nodes to the network, the end-to-end delay of the AODV routing protocol is still the lowest. This is because the AODV routing protocol does not consider the security factor, and its algorithm complexity is low. Due to the added security guarantees, SAODV and ISAODV routing protocols have higher computational overhead and higher algorithm complexity, so the delay is also higher.