A Hybrid Type DTN Routing Method Using Delivery Predictability and Maximum Number of Replication

In recent years, by spread of wireless communication terminal, a demand for wireless networks which can use anywhere and anytime is increasing. In some of wireless networks, communication environments have became with long time communication delay and occurrence of link disconnection. It was not supposed in current communication networks. In such a worst communication environment, Delay / Disruption / Disconnection Tolerant Networks (DTN) are paid attention as a communication technology with high reliability. In DTN, each node replicates messages to an encountered node and the receiving node repeats this procedure until the messages reach destination nodes. However, in DTN which assumes poor communication environment, it is difficult to determine nodes for replication. Since nodes in DTN control the replication by a routing method, communication performance changes by affinity of communication environments and routing methods. From these reasons, the routing method is important research target in DTN. In this paper, we propose a routing method which combines Spray and Wait, and Prophet. The Spray and Wait restricts a number of replications and the Prophet determines a replicated node by comparing delivery predictability for destination node. We aim improvement of message arrival rate by combining these two methods. From evaluations of experiments of real machine and simulation, we show that the proposed method has high message arrival rate than Spray and Wait, and Prophet.