# Research of Security Routing Protocol for UAV Communication Network Based on AODV
## 4 Simulation and Numerical Results  
In this paper, the network simulation software NS2 with an open source code and good scalability is used to build a network simulation platform, and the effectiveness of the proposed secure routing scheme is verified through simulation and evaluation. Table 4 shows the simulation parameters setting of the UAV communication network based on NS2. In this paper, the UAV communication network is arranged in a geographical range of 1000 m \(\times\) 1000 m. The UAV uses a random waypoint model and the data rate is set to 1 Mbps. The MAC protocol adopts 802.11 b protocol. The CBR source generates four packets per second, and the size of each packet is 512 bytes. Each simulation time is 300 s.  
The UAV communication network has the characteristics of open channel, dynamic topology, no center authorization, distributed cooperation, and limited bandwidth. It adopts the form of dynamic network to complete the interconnection of the internal members of the cluster. Considering the limited bandwidth and low capacity of UAV communication network, it is easy to be affected by signal collision and noise interference during communication. In this paper, the carrier sensing distance of the UAV communication network is set to 550 m, the UAV node coverage is set to 250 m, the bandwidth is set to 2 Mbps, and the transmission power is set to 0.28 W. All parameter settings support the special nature of the UAV communication network. In this paper, packet delivery radio (PDR), average throughput, and average end-to-end delay are obtained to evaluate the performance of the proposed secure routing protocol. \[\text{PDR}=\frac{\text{Number of packet received}}{\text{Number of packet sent}} \tag{11}\]  
PDR is the ratio of the number of packets received to the number of packets sent. From this ratio, it can be seen that the number of data was successfully transmitted in the whole network and the amount of data was lost due to link failure in the transmission process. This parameter can well reflect the efficiency of the routing protocol in data transmission. \[\text{Throughput}=\frac{\text{received packets}\times\text{packet size}\times 8}{\text{Total time of transmission}} \tag{12}\]  
Network throughput characterizes the network transmission rate. The larger the throughput, the higher the transmission rate. \[\text{Delay}=\frac{\sum(\text{Arrive time}-\text{Send time})}{\text{Number of connection}} \tag{13}\] \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Moving range of UAV & 1000 m \(\times\) 1000 m \\ UAV mobile model & Random waypoint \\ Number of UAVs & 50 \\ Maximum speed of UAV & 0–20 m/s \\ Traffic type & CBR \\ Packet transmission rate & 4 packet/s \\ The size of packet & 512 Byte \\ MAC protocol & 802.11 b \\ Data rate & 1 Mbps \\ Routing protocol & AODV, SAODV, ISAODV \\ Simulation time & 300 s \\ Carrier sensing distance & 550 m \\ UAV node coverage & 250 m \\ Bandwidth & 2 Mbps \\ Transmission power & 0.28 W \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Symbol definition. The end-to-end delay refers to the time between the source node sending data and the receiving node receiving data, including routing time and data forwarding time. It can reflect whether the network is unobstructed. The smaller the delay, the better the network. \[\text{Routing\,overhead}=\frac{\text{num\_rte\_pkt}}{\text{num\_ data\_pkt}} \tag{14}\]  
where, num_rte_pkt represents the number of control packets used for route discovery and route maintenance. The num_data_pkt represents the number of data packets received. The routing overhead represents the number of routing control packets needed to successfully transmit a data packet. The smaller the routing overhead, the less additional control packets are required for stable transmission of messages. The simulation experiment in this paper is divided into two situations. Firstly, the performance of ISAODV is compared with AODV and SAODV under normal conditions.