Accurate Probability Distribution of Rehealing Delay in Sparse VANETs In this letter, rehealing delay is analyzed for disconnected highway vehicular ad-hoc networks(VANETs). In the analysis, cluster length is first approximated by a simple but accurate, exponential-like mixed random variable. The relation between two successive network disconnections is then discussed to obtain the steady-state probability distribution of rehealing delay. Simulations show that the proposed analysis significantly outperforms previous works in terms of accuracy.