Analysis of rehealing delay for the delivery of downstream messages in sparse highway vehicular ad hoc networks

In vehicular ad hoc networks (VANETs), the delivery of messages may suffer from network disconnections due to medium or light vehicle traffic density or low penetration rate of a wireless communication device. When a network disconnection occurs, vehicles traveling in the opposite direction can generally help to restore it. In this paper, we analyze the mean delay incurred during the restoration of a network disconnection (i.e. the mean re-healing delay) for the delivery of downstream messages. Simulation results confirm that our analysis is very accurate. Furthermore, we show that the rehealing delay for the delivery of downstream messages is larger than that for the delivery of upstream messages.