Core Concepts
This study examines the dynamics of real-time data transmission, including video and LiDAR streams, from a remote-controlled ferry to a land-based control center over 5G networks. It evaluates key performance metrics such as throughput, latency, and packet loss to determine the bandwidth and latency requirements for reliable communication.
Abstract
This study explores the dynamics of real-time data transmission in 5G networks for remote-controlled maritime applications, focusing on a ferry called "Wavelab" in the Bay of Kiel, Germany.
Key highlights:
Simulation experiments:
Modeled two docking scenarios (REV and DIT) in the Gymir5G simulation platform to evaluate uplink and downlink performance.
Analyzed throughput, round-trip time (RTT), and packet loss rate (PLR) under different network conditions, including background traffic.
Identified factors affecting transmission performance, such as network congestion, handovers, and signal strength.
Concluded that the 5G network can provide around 50 Mbps under light workload, but drops to 20-30 Mbps with background traffic, potentially causing video streams to stall.
Showed that downlink performance is better than uplink, with stable throughput around 20 Mbps and acceptable latency.
Explored the challenges of using multi-homing (Wi-Fi and 5G) for data transmission, including Wi-Fi signal range limitations and out-of-order packet issues.
WebRTC protocol analysis:
Evaluated the use of WebRTC for real-time media streaming, including its advantages over UDP and TCP.
Implemented key WebRTC features in the Gymir5G simulator, such as NACK, FEC, and congestion control.
Conducted sandbox experiments to compare the performance of WebRTC with and without these features under different network conditions.
Demonstrated the effectiveness of NACK and FEC in improving reliability and reducing packet loss, while also highlighting the trade-offs with increased latency.
Observed that the default WebRTC parameters provide a good balance between performance and reliability, and further tuning may not bring significant benefits.
Real-world experiments:
Utilized the AhoyRTC Director platform to stream video from the Wavelab ferry to the land-based control center using WebRTC.
Measured the final latency for the entire data processing pipeline, including acquisition, encoding, and transmission.
Confirmed the feasibility of using WebRTC for real-time communication in the maritime domain.
The study provides valuable insights into the challenges and requirements for reliable real-time data transmission in 5G networks for remote-controlled maritime applications, paving the way for further advancements in this domain.
Stats
The ship can transmit around 50 Mbps of data under light workload conditions, but this drops to 20-30 Mbps with background traffic.
The downlink throughput remains stable at around 20 Mbps, with an RTT of around 200 ms.
The final latency for the entire data processing pipeline, including acquisition, encoding, and transmission, was estimated during the real-world experiments.
Quotes
"The range of the Wi-Fi signal is quite small: after 210 seconds it was lost and half of the traffic was not sent. This time step corresponds to the range of Wi-Fi for about 80 meters from the coast."
"While multi-homing offers potential benefits and an increase in bandwidth, prioritizing 5G for critical data transmission is critical to ensure reliable and efficient communications."