This paper presents OHMS-NetSim (Outdoor Heterogeneous Multi-Robot System Network and Physics Co-Simulation), an integrated simulation environment combining Docker-based network simulation and NetEm traffic control with Gazebo-based physics simulations. The motivation for this work stems from the need to develop and validate adaptive communication systems for cooperative perception applications, which require realistic testing environments that account for environmental communication constraints. OHMS-NetSim extends current co-simulation approaches by introducing obstacle-induced signal attenuation directly linked to the physical simulation, offering a tightly coupled and more faithful representation of real-world conditions. Designed for ease of deployment, this method promotes the adoption of network–physics co-simulation as a standard approach in multi-robot systems research. To demonstrate the platform’s effectiveness for developing communication-aware multi-robot systems, we also present OHMS-Comm (Outdoor Heterogeneous Multi-Robot System Communication), a Robot Operating System 2 (ROS 2)-based adaptive communication system, designed to facilitate information sharing within multi-robot systems operating in challenging outdoor environments. It is shown that in an Octomap sharing scenario, OHMS-Comm significantly reduces bandwidth usage while maintaining effective information flow between robots. This demonstrates that OHMS-NetSim provides a robust solution for simulating information sharing in communication-constrained outdoor environments, with significant potential for simulating a wide range of multi-robot applications including environmental monitoring, search and rescue operations, and distributed situation assessment in complex terrains.