WaveConnect : A LoRa Based Offline Communication System for Text Messaging

Over the past several years, there has been an increased need for reliable communications systems—namely, systems that do not rely upon any type of internet or cellular infrastructure—especially for use in remote, disaster-prone, and rural areas. In this paper we present an Offline LoRa-based Secure Communications System that utilizes ESP32 microcontrollers and a web-based interface, called WaveConnect, that is simple and intuitive to use. The communications system has a hybrid security approach, utilizing both lightweight scrambling and AES‑128 encryption. The WaveConnect user interface allows for people to communicate via chat on a mobile browser interface with ESP32 devices connected via the Web Serial API over a USB OTG connection. The communications system has long-range, low-power wireless data transfer capabilities with LoRa modules. The user interface’s communication through ESP32 devices utilizes a scrambling-before-encryption security method that results in very little overhead. Experiments showed that the communications system has an approximate range of 3.2 km in open areas with an encryption latency of only 28 ms. The combining of the hardware, security methods, and software interfaces creates a very inexpensive and low-power option for use in emergency, military, and remote locations without requiring any infrastructure.