# Improving Response Time for Crowd Management in Hajj
## 4 Experimentation  
The scenario shown in Figure 5 was selected to demonstrate the effectiveness of PRoFFAN in FANETs. In this scenario, the base station (sink node) is located near the field of interest. It has a range R of 500 m. Hence, the base station has a one km radio range. Seventeen UAVs pass by the base station, one by one, but at different speeds. The first UAV passes at a speed of 1 m/s (3.6 km/h). Therefore, the first UAV will be in the range of the base station for 1000 s. In this time, the UAV has to establish a connection with the sink and transmit one image. The second UAV passes at a speed of 2 m/s (7.2 km/h). As a result, the second UAV will have 500 s to establish a connection with the sink and transmit one image. The exact process continues for all seventeen UAVs. Hence, the last UAV passes at 17 m/s (61.2 km/h) and has about 1 min to establish a connection and transmit one image to the sink. All UAVs send the same image of 512 \(\times\) 512 resolution. As discussed in the Research Methodology section, the image is broken down into two layers. The high-priority layer is sent before the low-priority layer. The packet rate is set at 32 packets per second. Each packet is 100 bytes. Each byte contains either high-priority information of two pixels or low-priority information of two pixels. Hence, one packet contains information of 200 pixels. In our scenario, the UAVs try to send as much image information. In these experiments, we do not optimize the connection establishment between UAV and base station. All experiments are set with default communication parameters of Contiki-NG OS for RPL routing. Once a connection is established between the base station and the UAV, a UAV at 1 m/s should be able to transmit the entire image data, i.e., 2622 packets, in less than 90 s. Note that the 1 m/s UAV is in range of the base station for 1000 s, so it should be able to transmit the entire image. A UAV at 2 m/s should be able to transmit the entire  
Figure 4: PRoFFAN Packet Transmission Algorithm. image as well. However, UAVs at a higher speed would have less time to transmit the entire image. Additionally, packet loss may occur due to other reasons, such as multi-path fading, degradation of transmission, channel characteristics, etc. As soon as a packet of image information is received at the base station, PRoFFAN starts to decode the information and construct a received image. At the base station, PRoFFAN calculates image Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM) while receiving packets on the go. When the PSNR and SSIM reach the threshold required by the FANET application for processing images, PRoFFAN passed the image to the FANET application. Note that the goal of these experiments is to see if the introduction of PRoFFAN reduces the FANET application's response time. This paper focuses on single-hop image transmission between the UAV (Camera Node) and the base station (Sink Node). Therefore, only one UAV is in range for the base station. Each UAV travels a distance of 2 km, of which 1 km is in the sink range. Table 1 summarizes the simulation parameters. When one UAV reaches its end position, the next UAV starts its journey. In this way, the sink node collects packets from all UAVs, constructs received images, and calculates