Hybrid Architectural Network Implementation to Realize a Fire Evacuation Path with 2.4 GHz Zigbee and LoRa  
[PERSON]  
1 School of Electronics and Electrical Engineering, Lovely Professional University, Jalandhar 144001, India; [EMAIL_ADDRESS] (R.S.); [EMAIL_ADDRESS] (G.S.B.); [EMAIL_ADDRESS] (A.G.); [EMAIL_ADDRESS] (S.V.A.)  
[PERSON]  
1 School of Electronics and Electrical Engineering, Lovely Professional University, Jalandhar 144001, India; [EMAIL_ADDRESS] (R.S.); [EMAIL_ADDRESS] (G.S.B.); [EMAIL_ADDRESS] (A.G.); [EMAIL_ADDRESS] (S.V.A.)  
[PERSON]  
2 Department of Computer Engineering, Faculty of Science and Technology, Vishwakarma University, Pune 411048, India 2  
to a safe location. Generally, when a fire accident occurs, the fire emergency unit controls the fire with water and other procedures [4]. In this procedure, the fire emergency unit lacks a facility to monitor the building's fire status. At present, advancements in sensors and wireless communication technology provide an opportunity to enhance the existing infrastructure with accuracy and reliability [5; 6]. Wireless sensors and communication protocols have led to the evolution of wireless sensor networks (WSN) [7; 8]. Wireless sensors are used at physical objects to sense parameters and communicate with the server via a wireless communication protocol [9]. Moreover, real-time monitoring of fire safety is lacking in the WSN; real-time monitoring would enhance the fire authorities' ability to keep a continuous watch on the building fires [10; 11]. The wide availability of the internet enhances the utilization of IoT in various fields for realizing real-time monitoring from any location [12; 13]. Generally, in IoT, the role of the communication protocol is crucial because the IoT devices are energy-constrained [14; 15]. Moreover, it is recommended to utilize a low power consumption-based wireless communication system for implementing real-time monitoring. At present, Zigbee [16] and LoRa communication provide reliable data transmission with low power consumption. LoRa technology is one of the LPWAN emerging technologies that meets the requirements of IoT in terms of low power consumption and long-range transmission for real-time monitoring [17]. With the motivation of implementing a real-time monitoring system with advanced infrastructure, in this study we propose a real-time monitoring-based hybrid architecture for fire safety and evacuation paths in buildings. The proposed architecture is based on two different wireless communication, namely: 2.4 GHz Zigbee and LoRa communication.  
The contribution of the study is as follows.  
* In this study, a hybrid architecture was proposed and implemented to complete fire monitoring of buildings. The hybrid architecture integrates multiple systems such as a real-time vision-node for people estimation and smoke detection, an evacuation path display with the shortest algorithm, real-time monitoring of the building-related fire on the cloud server, and control of the water sprinklers through real-time sensor data.
* Customized hardware is realized for real-time implementation with 2.4 GHz Zigbee and 433 MHz LoRa communication with a node mapping feature.
* A simulation of 2.4 GHz Zigbee and 433 MHz LoRa is carried out to analyze the behavior of network parameters.
* The shortest path algorithm logged in the evacuation display controller shows the fire exit path based on sensor data received from the end devices.
* The vision-based system with a web application also shows real-time visuals for fire status and people detection.  
The structure of the paper is as follows: Section 2 covers the literature review. Section 3 covers the overview of LoRa and Zigbee communication. Section 4 covers the proposed architecture. Section 5 covers the hardware design of the detection end device, evacuation path display controller, safety operation controller, and gateway. Section 6 covers the simulation analysis of Zigbee and LoRa. Section 7 covers the experimental results. Finally, the article concludes.