The Intelligent Communications and Avionics for Robust Unmanned Aerial Systems group (ICARUS group) are formed by researchers of the Technical University of Catalonia. One of research lines is the automation and development of on-board avionics and ground systems in order to support either manned and Unmanned Aircraft Systems (UAS) while providing high levels of flexibility and low development costs. The ICARUS group developed a UAS simulation platform called ISIS which simulates UAS missions. This platform allows to study their behavior in interaction with the environment. However, it soon appeared the need to simulate more complex operations in which the UAS interacted not only the environment but also with air traffic. Eurocontrol (European Organisation for the Safety of Air Navigation) provided an Air Traffic Management (ATM) simulator platform called eDEP to ICARUS group. It opened the possibility of developing a simulation tool for integrating UAS into non-segregated airspace. This project has consisted of integrating these two simulation tools to build a new version of the UAS simulator able to integrate air traffic on ISIS platform. Air traffic will allow to create simulations in more complex environments.