I am trying to use SUMO in my MATLAB VANET simulator, and as per my understanding, SUMO is a standalone mobility simulator which can simulate different mobility models such as: car following (platoon), lane changing and traffic intersections. On the other side, the VANETs applications shall make use of the VANETs protocol messages (Beacon messages or EMG or whatever) and take actions based on these infos and update the vehicles' mobility as well.
I am already familiar with veins and plexe frameworks which already make use of SUMO via TraCI, however I can't understand the big picture for how they affect mobility in SUMO! For instance, in Plexe framework, sumo configuration files with vehicle routings can be loaded in SUMO and simulate the platoon scenario itself, so what is the value added from using VANETs protocol messages? The same for lane changing simulation, SUMO will perform lane change for vehicles based on certain conditions, so what have the VANET simulator to add using the VANETs protocol messages?