Creating swarms of robots can be tough. Different systems have to communicate while wandering around separately in a spacious area. The obvious solution in such a situation is to use a WAN connection. Even so, one obstacle remains, which is the safe communication of the different systems through this connection.
What can come in handy here is the eProsima Integration-Service, as addressing such a problem is one of the most critical and powerful application cases of this tool.
Using a pair of eProsima Integration-Service instances, or System-Handles, one for each system, this scenario can be addressed with a secure TCP tunnel thanks to the SSL TCP capabilities of Fast-DDS. Integration Service acts as a gateway to translate each system to DDS over SSL-TCP, after which a proper configuration of the destination router and firewalls will allow the communication.
Check a nice and instructive example on how to use the Integration Service for a similar purpose, which illustrates how it can be configured to get the classic talker-listener ROS 2 example up and running over WAN communication!