STEID: A Protocol for Emergency Information Dissemination in Vehicular Networks∗

This paper presents STEID, a spatio-temporal emergency information dissemination protocol for vehicular networks. Its main goal is to quickly disseminate traffic alerts about accidents or congestions to every car that passes through an emergency zone during the lifetime of the emergency. To achieve this goal, we propose a hybrid network architecture consisting of WiFi clusters connected through proxy servers and cellular links. STEID executes on top of this architecture and ensures the emergency message delivery to all the intended vehicles in a short time interval. Simulations conducted with hundreds of vehicles moving at speeds between 45mph and 70mph demonstrate this fact. We also compare STEID to a solution using only cellular communication with a central server for information dissemination. The results indicate that the average delay for STEID is between two and four times less than the one for cellular-only approach for regular highway speeds, while the traffic load imposed on the cellular network decreases by more than 65%.