Mathematical modeling of delivery delay for multi-copy opportunistic networks with heterogeneous pairwise encounter rates

This paper proposes an analytical model that captures the expected pairwise delivery delay in an opportunistic network when the source can generate multiple copies of the message. This model allows for the encounter rates among nodes to be heterogeneous, and it is completely independent of the forwarding scheme. The model is validated through simulation experiments performed with ns-3 and a multi-copy simulator specifically developed for this work. Along with the results, this paper also presents a discussion of the variability of the encounter rates over time and its influence on the accuracy of the proposed model.