Asymmetric Spray Based Routing for Delay Tolerant Networks

The framework of Delay Tolerant Networks (DTNs) has recently received an extensive attention and widely implemented, ranging from Wireless Sensor Networks (WSNs) to Interplanetary Networks. It has been applied in military communication, scientific research and exploration. Due to the characteristic of long delay, intermittent disruption, limitation of buffer space and energy, the traditional routing algorithms in the Internet do not perform well in DTNs. Since most of the existing DTN routing algorithms are based on the replication mechanism to achieve the high delivery ratio. In this paper, we propose an asymmetric spray algorithm based on the limited number of replication with the consideration of utility metric. In addition, we also design an adaptive replication function to optimize the dropped messages due to the insufficient encounter duration. Simulation results show the effectiveness of our asymmetric spray approach. In combination with the other designed functions, our proposed algorithm achieve a better performance than the state of the art algorithms.