Delay based Duplicate Transmission Avoid (DDA) Coordination Scheme for Opportunistic routing

Since the packet is transmitted to a set of relaying nodes in opportunistic routing strategy, so the transmission delay and the duplication transmission are serious. For reducing the transmission delay and the duplicate transmission, in this paper, we propose the delay based duplication transmission avoid (DDA) coordination scheme for opportunistic routing. In this coordination scheme, the candidate relaying nodes are divided into different fully connected relaying networks, so the duplicate transmission is avoided. Moreover, we propose the relaying network recognition algorithm which can be used to judge whether the sub-network is fully connected or not. The properties of the relaying networks are investigated in detail in this paper. When the fully connected relaying networks are got, they will be the basic units in the next hop relaying network selection. In this paper, we prove that the packet delivery ratio of the high priority relaying nodes in the relaying network has greater effection on the relaying delay than that of the low priority relaying nodes. According to this conclusion, in DDA, the relaying networks which the packet delivery ratios of the high priority relaying nodes are high have higher priority than that of the low one. During the next hop relaying network selection, the transmission delay, the network utility, and the packet delivery ratio are taken into account. By these innovations, the DDA can improve the network performance greatly than that of ExOR and SOAR.  Index Term-Opportunistic routing, coordination scheme, transmission delay, duplicate transmission.