LAUSR

To meet the requirements of long range, a small amount of data transmission, low power, and low cost of the Internet of Things (IoT) in actual applications, a low-power wide-area network information monitoring approach based on NB-IoT and LoRa is proposed in this paper. This approach adopts a communication mode that contains a main node and multiple subnodes to adapt to the needs of large-scale information monitoring. Among them, the design of the main node utilizes NB-IoT communication technology, LoRa communication technology, and least recently used algorithm. The design of subnode utilizes LoRa communication technology, sensor technology, and optical-electric conversion technology. Finally, we design and implement a cloud service and computing system, using the Tencent Cloud server. The advantage of this approach is that the combination of NB-IoT and LoRa not only improves transmission distance but also reduces the operating costs of the WAN information monitoring system. In addition, using optical-electric conversion technology, the system can be self-powered. Combined with the principle of electric circuits, the power consumption of the system can also be reduced. Finally, by conducting a system test, LoRa communication distance experiment, NB-IoT communication, and other experiments, the communication distance in a complex environment is up to 1.6 km, the minimum working current is 2 mA, and the system communication packet loss rate is approximately 3%. The system runs stably and the collected data are accurate. The results show that the proposed approach can meet the requirements of data collection, transmission, storage, and calculation in a wide area.