Impact of history on epidemic broadcast in DTNs

The broadcast diffusion of messages in Delay Tolerant Networks (DTNs) is heavily dependent on the mobility of the nodes, since protocols must rely on contact opportunities among devices to diffuse data. This work is the first effort of studying how the dynamics of nodes affect both the effectiveness of the broadcast protocols in diffusing the data, and their efficiency in using the network resources. The paper describes three simple self-adaptive control mechanisms that keep the broadcast overhead low, while ensuring high node coverage. Those mechanisms characterize a family of protocols able to achieve some awareness about the surrounding environment, and to use this knowledge in order to improve performances. Simulation results allow to identify the winning mechanisms to diffuse messages in DTNs under different conditions.