# Secure Utilization of Beacons and UAVs in Emergency Response Systems for Building Fire Hazard
## 5 Performance Evaluation  
In order to evaluate the performance of our UAV-EMOR system protocol, we implemented our day-to-day monitoring protocol on a commercially available augmented reality drone (AR.Drone) 2.0 for both indoor and outdoor monitoring. The AR.Drone 2.0 is a quad-copter equipped with front and ground cameras and Wi-Fi (2.4 GHz). It has a 1-GHz 32-bit ARM cortex A8 CPU and a 1 GB RAM. The main board of the AR.Drone 2.0 runs the BusyBox-based GNU/Linux distribution with the 2.6.32 kernel. We also used a personal computer with Linux OS as the control server and Raspberry  
Figure 8: The interface of the building Security Manager app. (**a**) first page of security manager app, (**b**) fingerprint authentication process, (**c**) security manager app in a normal situation, (**d**) an abnormal temperature is detected, (**e**) security manager app in abnormal situation, (**f**) rescue and emergency evacuation mode of security manager app  
Pi as a smart sensor. Figure 9 shows the experimental flow of the day to day monitoring protocol. In this experiment, we mainly evaluated the performance of the indoor/outdoor UAV and smart sensors during execution of the protocol, as they are resource-constrained devices. We measured the completion time of the protocol for day-to-day monitoring to evaluate the communication overhead according to flight altitude. For evaluating the communication overhead, we placed the server on the ground and periodically increased the drone's flying altitude, measuring the communication time between the UAV and the server at each altitude. The parameters used in the simulation are shown in Table 2. We measured the communication time between the UAV and the server under two different circumstances: (1) communication secured by an encryption algorithm, AES (Advanced Encryption Standard) on the AllJoyn Security platform, and (2) unsecured communication without using the encryption algorithm on the AllJoyn security platform. The communication time was measured from the time that a ping was sent from the server to the time that the drone's response ping was received back at the server. Figure 10 shows the communication overhead according to the distance between the UAV and the server. In Figure 10, we can see that, generally, the communication overhead increases as the distance between the UAV and the server increases. However, it can also be seen that the communication overhead is not significantly increased by the use of an encryption algorithm for a secure communication, as represented on the graph by the orange line. Figure 10: The communication and computation overhead according to flight altitude. Figure 9: The experimental flow of the day-to-day monitoring process. Moreover, in order to evaluate the computational overhead of the AR.Drone 2.0 (which we used as our indoor/outdoor UAV), we measured the encryption/decryption time of messages or images to complete the monitoring mission of UAV. Table 2 shows the time required to execute encryption and decryption algorithms for completion of a mission according to the size of the messages or images. When the size of the text message for transmission was 128 bytes, the UAV with our protocol took 1.1 ms and 0.9 ms to complete the protocol with encryption and decryption, respectively. Even for a large text size such as 10,240 byte, the UAV with our protocol encrypted and decrypted the message relatively quickly. It took only 180 ms to perform the encryption or decryption operation. Generally, images take longer to encrypt and decrypt than text messages do. However, our system is still relatively fast in this regard. It took the UAV 15 ms to encrypt/decrypt 473 bytes (one or two images). For the secure transmission of 10,703 bytes (about six or seven images), the UAV took 306 ms. Furthermore, in order to evaluate the computational overhead of the smart sensor, we measured the cryptographic operation time such as the encryption or decryption time of messages to securely communicate with the UAV.