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In vehicular ad hoc network (VANET), the standard topology changes caused by the fast mobility of nodes create many challenges to the efficient data delivery in vehicular environment. The density-, mobility- and location-based dissemination technique can fulfill the needs of emergency message broadcasting. Emergency message broadcasting in both highway and urban scenarios has so many problems such as high reliability, low latency and scalability that remains unsolved. The road structure, message redundancy, channel contention are the major issues in urban scenarios. Usually, broadcast protocols for VANET use beacon messages, which is disseminated among the vehicles, in order to get neighborhood information. When the vehicles are next to each other trying to broadcast at the same time, this may lead to frequent contention and broadcast storms. On the other hand, in sparse density scenarios …