Research On Cooperative Forwarding Mechanism In Mobile Social Opportunity Network

With the popularity of social network service and the development of mobile terminals, mobile social networking opportunity services gradually flourished as a product of opportunities network and social network combining, and showing a good development trend. Mobile opportunity social network with no fixed infrastructure, the nodes in the network will achieve communication with each other according to the social relationship between them by using all kinds of mobile devices and taking the "storage-carry-forward " data transmission mode. However, due to memory, bandwidth, energy restriction, some nodes do not participate in network collaboration in order to maintain its own interests and save resources. So, how to encourage the nodes to collaborate forwarding message is the key of the network communication research problem. This thesis has carried on the research on node collaboration forward incentive mechanism by analyzing the relation between the nodes and the strength of the social relations.This thesis first summarize the mobile social opportunistic networks, including the concept of mobile social opportunistic networks, research background, the research actuality at home and abroad, the main application and the critical issues and so on. We analyze the causes of selfish behavior, species and the current routing algorithms, summarize the advantages and disadvantages of them. These routing algorithms mainly focus on how to improve the performance of network communication, such as:transfer success rate, forward delay, etc. But they did not take into account the actual device holder movement characteristic and the social relationship between them, and the intensity of the different social relations between nodes is different. Social relationship of some nodes is weak due to the weak connection between them. These nodes presented a kind of selfish and we call them "selfish" nodes. If the number of "Selfish" nodes is lager, it will have great influence on the performance of the network, so it is necessary to take some measures encouraging the "selfish" nodes involved in the transmission of messages.To deal with the strong dynamic of mobile social networking opportunity and the big number of the "selfish" nodes, this thesis proposed a Social Relations Routing (SRR) protocol. The protocol evaluates the social relations of nodes in the opportunistic network by analyzing the physical social relations of nodes and the contact probability of nodes, and dynamically updates the social relation matrix. Source node or the current node chooses the strong social relations node as an intermediate node to forward messages to the destination node according to the social relationship matrix. But, to those nodes whose social relations is weak, we design a coordination mechanism, to promote the "selfish" nodes involved into the message transmission, and avoid the "selfish" transfer node discarding the message.Finally, this thesis use the network simulation tools to simulate the performance of SRR algorithms and collaboration mechanisms. SRR algorithms has certain advantages in data transfer rate and transmission cost through comparing with Prophet and SimBet routing algorithm. By compared with other collaboration mechanisms, the cooperation mechanism proposed in this thesis has a better performance of cooperation between the selfish nodes, transfer in success rate and network throughput.