CTR: Carry Time-Based Routing for Increasing Delivery Ratio in Mobile Social Networks

摘要

Mobile social network is a kind of social networks through which the nodes have some social features such as: gender, job, friendship relations, centrality, and so on. The nodes mobility, leads to avoid forming connected routes between the source and the destination all the times. Therefore, routing is one of the main challenges in these networks. In such networks for routing store-carry-forward pattern is used. In this method each node produces a packet or receives it from another node, carries it until it finds an appropriate opportunity, and delivers it to the encountered node when an opportunity occurs. During the time interval through which the node tries to find a good opportunity and carries the packet is called carry time. Most proposed routing methods have had some suggestions on store step or forward step. It seems that we can improve routing in these networks through considering carry time by the nodes. This means that the longer carry time of a node shows that it is not an appropriate candidate to redistribute the packet. In this paper a routing algorithm based on carry time (CTR) is proposed. In this method carry time by the nodes is saved for each packet. The proposed method was presented considering three states of single-copy and only based on carry time, single copy and based on carry time and the probability of encountering the nodes, and multi copy and quota based on carry time and encountering the nodes. The simulation results show that proposed method optimized regarding delivery ratio and the average delay compared to the related works.