Micro-ROS is an embedded framework allowing you to connect low-power, cheap IoT devices into a ROS 2 system. By using Micro-ROS together with Husarnet peer-to-peer VPN your robot doesn't need to be in the same LAN as an IoT sensor.
Thanks to that your robot can be mobile/5G connected and talk directly with IoT sensors or actuators connected over Wi-Fi. Without any proxy server in between.
In this article I present a ready to use GitHub template for ESP32 Wi-Fi microcontroller allowing you to bring your ROS 2 powered IoT sensors to life in minutes.