Possibility of Using Existed WLAN Infrastructure as an Emergency Network for Air-to-Ground Transmissions: The Case of WebRTC-Based Flying IoT System

In many urban and industrial areas, there exist wireless network infrastructures - usually complex, covering large public buildings (often with adjacent parking lots and green areas). In the case of emergency situations, such infrastructure could be used as a production network (i.e. a network dedicated to the transmission of user data) for creating ad-hoc flying monitoring systems, composed of one or more air stations (drones equipped with specialized sensors and detectors, as well as a high resolution camera), and corresponding ground station(s). This paper proves that the existing network architecture is able to play a significant role in the casual assurance of suitable air-to-ground transmission of monitoring data. Transmissions are carried out between two WebRTC applications of IoT brokers, placed on the air station, and on the ground one. The stations are connected through the IEEE 802.11ac (Wi-Fi) production network. During experiments, two different wireless local area networks were used as a production network. The first one was dedicated to transmissions coming from the flying monitoring system. The second one was the private network of the AGH University of Science and Technology, available for the academic community. Results of experiments show that although a dedicated network better fits the needs of the flying monitoring system, a well-dimensioned public network that has good coverage of the monitored area is able to effectively replace it in an emergency.