Research On Information Aided Routing Algorithm In Mobile Opportunity Network

In recent years,with the rapid development of wireless communication technology and the large-scale popularity of portable devices,a network environment where people,the interconnection of machines and things is gradually being formed.However,under some special network scenarios or application requirements.the mobility and uneven distribution of nodes cannot ensure that the network is completely connected in a real-time manner,which leads to a decline in the performance of the traditional network communication methods or even the inability to use them.The Mobile Opportunity Network(MONs),which has the characteristics of data communication under the condition of none real time Unicom,can meet the communication requirements of the above network scene.However,there are still many challenges in the development of the MONs.such as how to ensure the sharing efficiency of content(auxiliary-information)under the premise of reducing the waste of mobile terminal resources,and how to optimize the transmission performance of the content(data packet)in the case of a weak local network topology.Therefore,saving resources and optimizing transmission is an important problem in the research of MONs.In order to deal with the aforementioned challenges,in this paper,we make a study of MONs from two aspects,one is the auxiliary-information collection mechanism and the other is routing algorithm.The main contributions of our work are demonstrated as follows:(1)In opportunistic routing protocols,the exchange process of the auxiliary-information among nodes is performed in an epidemic fashion,which consumes more network resources.Motivated by this problem,this paper proposes a hierarchical auxiliary-information acquisition mechanism.Firstly,nodes which are neighbors exchange information,so as to have a faster update.Secondly,in order to have a higher network coverage rate of auxiliary-information,the nodes are classified into core nodes and boundary nodes and take high-social nodes as the core nodes,the acquisition of auxiliary-information mainly occurs between the two types of nodes to assure the higher network coverage.Selectively sharing information can significantly reduce the auxiliary-information exchange times between nodes.(2)For the problem of how to minimize waste of resources(Efficient)on the premise of ensuring auxiliary-information sharing(Effective).This paper proposes an auxiliary-information collection mechanism that considers efficient and effective.First,Based on the division of nodes,the core nodes are responsible for the collection and diffusion of auxiliary-information to ensure the efficient of auxiliary-information sharing.Then the core node selection problem is converted into a minimum coverage problem.By mathematically verifying that the minimum coverage problem obeys the sub-module property,and based on this,a greedy core node selection algorithm and a coverage-based core node selection algorithm are proposed to ensure the effective of resource conservation.(3)Data transmission performance degradation caused by node mobility and weak local connectivity.Motivated by this,a distributed social distance routing algorithm was proposed.Firstly,social-distance among nodes is constructed by the friend relationship.Then,each node maintains a table for recording the shortest social distance of other nodes,and the minimum social distance is continually updated by exchanging and comparing the information in the table.The construction of social distance only needs to exchange information among friends instead of all nodes,so it can greatly reduce the number of auxiliary-information exchange.Finally,when the packet is sent to the relay node with a smaller social distance to its destination node,the delivery-ratio can be significantly improved.