Speed Detection in VANET using OMNET++ for broadcasting data video

I need help in my project, that is velocity detection on vehicles on VANET using omnet++, sumo, open street map and veins. When some cars on the road that get in a Road Side Unit(RSU) range and in front of there is a red traffic light, and the speed is slowing down(about 40km/h to 10km/h) then a data in form of video will be sending by the RSU to that vehicles. But when the traffic light is green and the speed is up(about 10km/h to 40km/h) then no video will be sending to that vehicles.