Research On Resource Location And Dissemination For Mobile Peer-to-Peer Computing

With the development of mobile networks and Peer-to-Peer computing, Mobile Peer-to-Peer (MP2P) computing has become a popular network computing paradigm by several advantages, such as infrastrucuture-less support, flexible self-orgnization and cost-effiecient way. Compared with peer-to-peer systems, mobile peer-to-peer systems exhibit some special characteristics, such as high dynamic and limited-resource, which have brought many challenging problems for MP2P research. Resource location and dissemination are very important basic problems in the research field. In this paper, to improve the communication performance of MP2P system as the goal, around resource location and dissemination, we focused on the technologies of connectivity, message routing and resource dissemination. The specific work and contributions are:1. Based on the probability analysis of dependent edges, this paper proposed the calculation method of connectivity for the MP2P network. Currently there are many connectivity analysis methods. The classic approach is mostly on the base of an assumption that the edge distribution is an independent event. However in the actual network the existance of edges is dependent and the independent edges occur as a small probability event. Firstly, we distinguished the independence edges and dependence edges in the MP2P network, defined the whole set containing all the edges and the ignored set only containing the independent edges. In this paper we used the different set of the basic set and ignored set called the basic set to analize connectivity. Then we introducted the the smallest subgraph composed of dependent edges, which is the "atomic subgraph" used to decomposite the random graph by the technology of network coverage set. According to two scenarios, finite network boundary and infinite network boundary, we respectively gave the classification of nodes level, and determined the probability of connectivity between neighbors inside out. Finally we had the connectivity probability formula of any two nodes. The simulation shows that with comparation of classic flooding routing protocols, the routing protocol calculating probability of connecitivy with the relevant edges can gain better routing success rate and reduce average routing delay, routing overhead, reduce average routing length.2. On the base of VRR (Virtual Ring Routing) routing protocol, this paper design the 6DMPP routing protocol consistent with the small world model. VRR is the first international MP2P routing protocol with high performance, which is based the concept of DHT (Distributed Hash Table). But VRR does not research the influence on routing performance which comes from nodes' activity on mobile social networks. Therefore, under the characteristics of small world model of social network, this paper presented the long link and its probability replacement method based on VRR. Our work is to increase the intersection probability of links. We also showed that the probability of long link replacement method is consistent with the small world model. The results show that, compared with VRR and other classic routing protocols, 6DMPP can improve routing performance, meanwhile by the designed link repair mechanisms, the effectiveness of 6DMPP can be ensured.3. The bandwidth adaptive multicast mechanism Together which consist of a multicast tree as backbone and an assistant mesh for MP2P network. In mobile network with unreliable connection, limited bandwidth and limited processing power, the data dissemination will directly affect the efficiency of the whole MP2P system, so the multicast service is an important data distribution service for MP2P appliations. However, existing mechanisms for multicast on the Internet less consider the above situation on multicast performance. This paper analized the multicast tree problem of uneven bandwidth usage, and then introduced an assistant mesh and the bandwidth adaptive multicast mechanism. Analysis of results showed that compared with existing mechanisms, Together can achieve better multicast performance.4. In the Android mobile operating system we designed and simulated the support platform for MP2P called MOBIPEER. In this article we firstly summarized the naming, publishing, organizating and interactive functions, and then described MOBIPEER structure. We designed and implemented the function of connectivity analysis and the routing protocol 6DMPP mainly on discovery module and routing module of MOBIPEER. Finally based on Together, we developed an instant text messaging application on Android.