Quasi-real time remote video surveillance unit for LoRaWAN-based image transmission

The aim of this paper is to demonstrate the usability of the Long Range Wide Area Network (LoRaWAN) transmission technology for the implementation of a quasi-real time Video Surveillance Unit (VSU) to be employed for remote monitoring within the safety and security application domains. The VSU is provided with motion detection features that allow for actual transmission only of significant images: once that motion is detected within the camera field of view, image is acquired, processed, compressed and subdivided to fit within the maximum LoRaWAN payload size. The paper presents software and hardware architecture of the VSU as well as a set of preliminary tests carried out in an indoor environment, with different dynamic activities within the camera field of view. Image transmission by means of LoRaWAN connectivity is achieved keeping the average overall transmission timing in the order ten minutes, fulfilling all the requirements and limitations foreseen by the LoRaWAN specification: the system proved to be able to satisfy the quasi-real time requirement for the aforementioned application contexts.