A communication device for a vehicle to communicate features about the vehicle's environment includes one or more processors configured to receive a communication from another device, wherein the communication includes a global reference coordinate system for an area covered by the other device and a number of allowed transmissions to be sent from the vehicle; transform stored data about the vehicle's environment based on the global reference coordinate system; divide the transformed stored data into a plurality of subsets of data; and select one or more subsets of data from the plurality of subsets for transmission according to the number of allowed transmissions.