my recent work swarm_ros_bridge for multi-robot ROS message communication:
ROS wiki: swarm_ros_bridge - ROS Wiki
swarm_ros_bridge is a lightweight middle interface ROS package mainly based on ZeroMQ. It enables the specified ROS message transmission among swarm robots through socket communication. The purpose of this package is to replace the traditional way of running ROS across multiple machines in ROS1 , which has some drawbacks under the swarm robots situation.
An example of two ROS robots communicating with each other through swarm_ros_bridge is shown below:
Some discussion: Announcing the ''swarm_ros_bridge'' ROS package for muti-robot communication