ROS2 Connect: A new ROS2 over WAN Solution
This paper introduces ROS2 Connect, a WebSocket-based client-server framework that enables secure, transparent, and scalable ROS2 communication across wide-area networks by overcoming the limitations of multicast-dependent discovery mechanisms while outperforming existing solutions like DDS Router, rosbridge, and Zenoh in latency and stability.
Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine a fleet of robots working together, each needing to share information instantly to navigate a warehouse, assist in a rescue, or explore a distant planet. For these machines to function as a single, coordinated unit, they rely on a shared language called the Robot Operating System 2. This system acts as the nervous system for modern robotics, allowing different parts of a robot, or even different robots entirely, to talk to one another. However, this language was built with a specific assumption: that all the machines are sitting in the same room, or at least on the same local network, like devices connected to a home Wi-Fi router. In this local setting, the robots shout out their presence and listen for answers using a method that works perfectly when everyone is nearby. But when you try to move a robot to a different city or a different continent, this shouting method fails. The internet, which connects these distant locations, does not allow this kind of broadcast shouting to pass through its routers. Consequently, trying to control a robot from afar has historically been a difficult puzzle, often requiring complex, custom-built networks or leaving the robot unable to communicate at all.
To solve this problem, a team of researchers from the University of Würzburg in Germany has developed a new tool called ROS2 Connect. Their goal was to create a bridge that allows these robots to speak their native language across the vast distances of the internet without needing to change the underlying network infrastructure or reconfigure the robots themselves. Instead of relying on the shouting method that fails over long distances, the researchers built a system that uses a standard, reliable connection known as a WebSocket. You can think of this connection as a dedicated, secure telephone line that stays open between the robot and the human operator, regardless of how many routers or firewalls stand between them. The system works by placing a small software program on the robot's local network that acts as a server, and a matching program on the operator's computer that acts as a client. When the operator wants to send a command, the client program packages it and sends it over this secure line to the server, which then delivers it to the robot. The process works in reverse for the robot's data, allowing the operator to see what the robot sees and feel what it feels in real time.
What makes this approach particularly clever is that it does not force the robot to change how it thinks or speaks. The researchers designed the system to be transparent, meaning the robot continues to use its standard software components exactly as it would in a local room. The new software simply intercepts the messages, wraps them in a secure container, and sends them across the internet. It also handles the tricky business of security, ensuring that only authorized users can connect. Before any data is exchanged, the system requires the operator to prove who they are, much like showing a key card to enter a secure building. Once verified, the system only allows access to specific parts of the robot's data that the operator is supposed to see, preventing anyone from accidentally or maliciously accessing sensitive information. This design ensures that the connection remains safe and controlled, even when crossing public networks.
To test if this new method actually worked better than existing solutions, the researchers set up a real-world experiment. They connected a computer in a residential home to a server located at their university, simulating a typical long-distance connection. They then measured how long it took for messages to travel back and forth between the two points, testing everything from tiny control signals to large images from a robot's camera. They compared their new system against three other methods that are currently used to connect robots over the internet. The results were clear and consistent: the new system was faster and more stable than the others. When sending small messages, all the systems performed reasonably well, but as the size of the data grew, the other systems began to slow down significantly. The new system, however, maintained a steady speed, delivering messages with very little delay even when the data was large. It also showed much less variation in its speed, meaning the time it took for a message to arrive was predictable, a crucial factor for tasks like driving a robot remotely where timing is everything.
The researchers also tested how the system handled multiple streams of data at once, simulating a busy environment where a robot might be sending video, sensor readings, and control signals simultaneously. Even when ten different streams of information were flowing at the same time, the system remained stable. While the time it took to send larger messages did increase slightly as more data was added, the system handled the load efficiently without breaking down. This performance suggests that the new tool is well-suited for the complex demands of teleoperation, where a human might need to control a robot in a disaster zone or a remote factory with high precision. The study confirms that it is possible to extend the reach of robotic systems across the globe without sacrificing speed or safety, offering a practical foundation for the future of distributed robotics. The work does not claim to solve every possible networking challenge, but it provides a reliable, secure, and efficient way to connect robots over the internet, removing a major barrier that has long limited how far these machines can be controlled.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.