  Delay-Tolerant Networks (DTNs) have emerged as an exciting research area with
a number of useful applications. Most of these applications would benefit
greatly by a reduction in the message delivery delay experienced in the
network. The delay performance of DTNs is adversely affected by contention,
especially severe in the presence of higher traffic rates and node densities.
Many-to-Many (M2M) communication can handle this contention much better than
traditional one-to- one communication employing CSMA. In this paper, for the
first time, we analytically model the expected delivery delay of a DTN
employing epidemic routing and M2M communication. The accuracy of our model is
demonstrated by matching the analytical results against those from simulations.
We also show using simulations that M2M communication significantly improves
the delay performance (with respect to one-to-one CSMA) for high contention
scenarios. We believe our work will enable the effective application of M2M
communication to reduce delivery delays in DTNs.
