Design And Implementation Of Emergency Communication System Based On LoRa

Traditionally,emergency communication systems are most the public emergency communication systems which are set up by government or public organizations temporarily,and they are often costly.Also,there are not so many people concern about routine emergency communication systems for personal use home and abroad.For solving these problems,the system proposes a new design of emergency communication system based on low power wide area network LoRa,which is a new wireless spread spectrum technology.This system can communicate in a long range with an ultra-low power consumption.This article mainly achieves a kind of personal emergency communication system and come up with a new thinking of setting up emergency communication system based on low power wide area network such as LoRa and etc.,which is applicable and practical broadly.The emergency communication system designed by the article can be divided into three parts: personal portable device,relay base station and application software by different function of different parts.The main function of personal portable device is message sending and receiving,a key for help and so on;the relay base station is used to relay message,respond to help information and so on;and we use an application software to connect the personal portable device,type in the message we want to send and see the message we received.The connection and communication between personal portable device and relay base station is based on LoRa,and the protocol follows the LoRaWAN protocol stack,from which we design the user's information format to ensure the correct sending,relaying and displaying of the message.The personal portable device and the application software connect with each other through Bluetooth,and its protocol is transparent transmission based on Bluetooth version 4.0.Message is typed in by users from application software and sent to personal portable device through Bluetooth,then is transmitted to receiving user through LoRa network by the relaying of relay base station,finally is displayed on the application software.Above is the whole transmission of the message.After multiple debugging and remote testing,the emergency communication system designed by this article has achieved bidirectional data communication,which can be a reference for the follow-up research.