Measurement of latency during real-time wireless video transmission for remote supervision of autonomous agricultural machines

As the prominence of autonomous vehicles continues to rise within agriculture, remote surveillance of the equipment is likely to become a key aspect of operation. Transmission latency during the relay of video from vehicle to viewer is not well explored and is an important part of communications which should be assessed. A riding mower was equipped with a Raspberry Pi using GStreamer and an open-source latency measurement library to assemble a real-time streaming system to evaluate transmission latency in different environments using cellular and radio transmission. In most locations, measured latencies were under 200-300 ms. In areas where cellular connection quality was adequate, cellular latency and variance were reduced compared to that of radio transmission for higher qualities of video. In areas of poor cellular network coverage, cellular transmission latency increased while radio transmission latencies remained constant. Overall, latency tends to increase with video quality to a statistically significant degree. It is recommended that real-time video can be transmitted over short distances for edge-of-field surveillance of autonomous agricultural machines using existing cellular networks in areas where adequate cellular signal strength is available. If adequate cellular signal strength is not available in a specific field location, it is recommended that video should be transmitted using radio transmission.