Modeling opportunistic communication with churn.

•We establish stochastic models for two epidemic content spreading schemes and we validate our models by means of simulation.•We investigate five mobility scenarios including: realistic simulator-based traces, two sets of real-life traces and synthetic mobility.•We analyze the scenario-specific distributions of the contact rate and node sojourn time, and we compare these empirical distributions with modeling assumptions.•We study contact patterns in systems with churn and provide an approximation of the contact rate for the system in the transient state.•Based on the proposed modeling approach, we demonstrate an estimation method for the system parameters.