  Most V2X (Vehicle-to-Everything) applications rely on broadcasting awareness
messages known as CAM (Cooperative Awareness Messages) in ETSI or BSM (Basic
Safety Message) in SAE standards. A large number of studies have been devoted
to guarantee their reliable transmission. However, to date, the studies are
generally based on simplified data traffic models that generate awareness
messages at periodic intervals or with a constant message size. These models do
not accurately represent the real generation of CAM messages that follow
specific mobility-based rules. Using simplified and unrealistic traffic models
can significantly impact the results and validity of the studies, and hence
accurate models for the generation of awareness messages are necessary. This
paper proposes the first set of models that can realistically generate CAM
messages. The models have been created from real traces collected by two car
manufacturers in urban, sub-urban and highway test drives. The models are based
on mth order Markov sources, and model the size of CAMs and the time interval
between CAMs. The models are openly provided to the community and can be easily
integrated into any simulator.
