The Research Of Data Disseminating Optimization In Mobile Opportunistic Networks

Mobile Opportunity Networks(MONs)is a network model for the lack of a continuous end-to-end connection,some of its concept from delay tolerant network(DTN)research.Mobility of the nodes in the network causing link disconnected and network partition,and the node limited by storage capacity and energy costs,therefore the data transmissions in MONs faces huge challenge.The traditional method does not consider the data size,when arises tremendous needs for large size file transmissions in MONs,such as multimedia advertisement distribution or video sharing,the storage space of relay nodes is becoming the bottleneck of achieving higher performance.And multicast is an important research topic of MONs.The traditional multicast routing is necessary to predefine the destination group.However,when destinations are not predetermined,achieving efficient data routing in this scenario can be very challenge.This paper mainly makes two aspects about multimedia data transmission and multicast routing in MONs.The multimedia data transmissions refer to unicast of multimedia data and broadcast multimedia advertisement.And the multicast includes K-Anycast and M×N search routing.The primary content as follows:(1)To solve the contradiction between limited storage capacity and big multimedia data size in MONs,this dissertation proposes the multiple knapsacks based solution which can achieve the local optimal in a distributed manner.And the contact duration is considered so that the arrangement has to follow the constraint of communication capacity.(2)To the question of delivering multimedia advertisements which have big data size in VANET,this dissertation proposes TaxiCast which is a taxi based broadcasting scheme.It first applies signal strength based coding and decoding to obtain the demanding of the surrounding vehicles.Then it solves the advertisements selection process as a knapsack problem combined with communication capacity and multimedia data size.(3)This dissertation investigates a special multicast named K-Anycast.To solve the problem,first model it as a resource allocation and propose to solve it using bipartite matching,and then build a layered.Based on this structure,two algorithms(K-Cast and K-Epidemic)are proposed.(4)This dissertation investigates the M×N multi-source manycast problem in Mobile Opportunistic Networks.To solve the problem,first propose a layered hierarchical structure constructed in the proactive mode,and the forwarding will along the upstream direction of such a structure.Based on this structure,propose the algorithm in the single copy model first and then extend to multi-copy delegation to further reduce the delay.