Hi guys,
This is a “hot” topic, and we have been working during the last 2 months to benchmark the behavior of ROS2/DDS on WIFI scenarios.
In order to do that, we have this cool raspberry pi farm fully dedicated to our tests:
30 Raspberry pi connected to wifi networks, using different routers, and running different cases over wireless and wire setups, to benchmark everything. In a single Raspberry pi we can have multiple ROS2/DDS participants, with many publishers and subscribers.
Everything is automated, and we can run any test just with a single command. We are preparing an article with the conclusions.
In short: It is true that many wifi scenarios have a lot of packet loss, especially when using multicast, and this is more noticeable when you have many nodes on the same wifi network. But in simple wifi scenarios, ROS2 works out of the box.
We have written some tutorials on how to setup Fast RTPS when you notice such problems as an initial guide:
and we have already some good data, in complex scenarios, for example, 30 Raspberry PIs, 1 Participant per Raspberry PI, with 5 publishers and 5 subscribers, using discovery server (best solution when you have many nodes and a lossy network)
In that specific case, the start-up time of the system is around 3 seconds, a good number in these scenarios.
We were waiting to have a full set of results with a comprehensive set of scenarios, to write a detailed article, but as this is a hot topic, we will write several articles while we complete the work, and we will update our configuration guides.