Assessment of Video Transmission Delay from a Telemetry Surveillance System

The emergence of the Fourth Industrial Revolution along with the rapid development of advanced technologies such as the Internet of Things (IoT) has addressed a significant portion of the essential needs of an ever-changing digital society. Among these needs, remote environmental monitoring systems play a crucial role. This paper presents such a monitoring system, which incorporates compact devices like Raspberry Pi. The system is assembled and programmed to transmit images or videos from the environment via the Internet to end-user devices. To transmit video from the monitoring station to the end-user devices, commonly used video streaming protocols such as HLS, DASH, RTMP, and RTSP were tested in practical scenarios. The authors observed differences in video transmission latency among these protocols through various experimental setups. Specifically, HTTP-based protocols like HLS and DASH exhibited higher transmission latencies compared to the RTMP and RTSP protocols, and significantly higher latencies than the video encoding latency at the IoT device. The primary reasons for these discrepancies lie in the differences in real-time video streaming techniques and video encoding technologies employed by each protocol.