# Data Traffic Modeling in RPAS/UAV Networks with Different Architectures
## 5 Results  
This section presents the calculated dependencies of the average utilization for the \"BS-RPAS1\" link (AU1) on the TS parameter, the link bandwidth and the BER. The average channel utilization refers to the average traffic on a given channel as a percentage of a total channel bandwidth. The channel bandwidth is the amount of information in bits per second that a channel can pass over a certain time period. In addition to the average utilization, such parameters as message travel time, the number of dropped packets, and the average workload were also calculated. For simplicity, this article provides data for the average utilization only. It is necessary to find how the architecture of the models is related to the quantitative characteristics of traffic. How can adding of one or two new RPASs change traffic? How does traffic change across models with different architectures in response to increasing transaction sizes? At what size of transactions is the channel closed? Does this happen for the same values in different architectures? All distances were considered to be equal to 10 km, as indicated in Table 1. The goal was to find out the average AU1 link utilization for different models. Figure 3 shows the dependencies of the AU parameters for the \"BS-RPAS1\" channels on the size of the Common Data transactions for different models. At the same time, Tactical Data traffic remained constant with TS = 100 Kbits. Messages of both types of traffic are sent every second. The nature of the dependencies is approximately the same for all models. The AU values practically do not change for TS parameter values from 10 bits to 10 Kbit, increasing only for TS = 100 Kbits. The increase in the AU parameter occurs as the transition from  
Figure 3: Dependencies of Average Utilization (AU) for AU1 link on Common Data Transaction Size (TS) (Tactical Data—File Transfer Protocol (FTP), TS = 100 Kbits, Time Between Transactions (TBT) = 1 s, Const law; Common Data—Local Area Network (inter LAN), TBT = 1 s, Const law; and Bit Error Rate (BER) = 0%). Model 1 to Model 4, that is, as the architecture of the models becomes more complex. When TS > 100 Kbits, the channel is closed for all models. The transmission of Common Data becomes impossible in the case of the selected transmission conditions for Tactical Data traffic. The results for Models 1 and 2 are practically the same (for example, \(\approx\)2.5% and \(\approx\)2.7%, respectively, for TC = 1000 bits), but with increasing complexity of the model architecture, the AU parameter becomes equal to \(\approx\)5.7% (Model 3) and \(\approx\)7.5% (Model 4). The increase in the load of the AU1 channel during the transition from Model 1 to Model 4 occurs almost three times. The established requirements for the cellular communication of the RPASs/UAVs [8,36] correspond to the data transfer rate over the Command and Control channel \(\sim\) 100 Kbps and the payload channel \(\sim\) 50 Mbps. That is why when obtaining the dependencies shown in Figure 3, for Tactical Data the parameters TS = 100 Kbits, TBT = 1 s were chosen. At the same time, the data transfer rate or bandwidth for Tactical and Common Data in all network branches was T3 (44.736 Mbps), as indicated in Table 1. However, in reality, the data transfer rate may decrease due to different reasons. As the bandwidth decreases, less and less information can pass through the channel per unit of time. How can a change in data transfer rate affect network load in models with different architectures? With what data transfer rates models can operate? The answers to these questions are contained in Figure 4.  
The dependencies of the AU parameter on AU1 link bandwidth for all models (Figure 2) are shown in Figure 4. The bandwidth ranged from 6 Mbps to E3 (34.368 Mbps) and T3 (44.736 Mbps). Dependencies are given for TS = 1 Kbits for Tactical Data traffic and TS = 10 Kbits for Common Data traffic.