Comparison of Policies 1 Running head: COMPARISON OF POLICIES FOR EPIDEMIC BROADCAST IN DTNS Comparison of Policies for Epidemic Broadcast in DTNs under Different Mobility Models

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