Peer-to-Peer Resource Locating And Retrieval Model Under Wireless Network

Nowadays, with the development of both wireless network and personal mobile device, people are accustomed to access information via wireless network from anywhere at anytime. Also, people more and more want to share and transfer the data between their mobile devices. And more and more people are interested in applying P2P under wireless network. There comes out a new concept called MP2P.Resource locating is a key problem of an efficient MP2P system. But with the restraints of wireless network and mobile device, such as highly dynamic topology, low communication bandwidth and limited battery capacity of the device, the strategy of MP2P's resource locating is different from normal ones.The main work of this paper is as follows.(1)We give a high resource hitting rate and short delay model. It uses the DHT and region partition as our basic resource locating method for quick searching.(2)We introduce super peer to improve efficiency of resource hitting and avoid the poor situation when using flooding request.(3)As existed model didn't consider the situations of imbalanced distribute very much, we give a strategy to improve the efficiency when the problem occurs.(4) We give the solutions to deal with the 'trashing' situation existed in most models, which means peers move frequently between two regions' borderline. When this situation occurs, most of this network's cost will be expended in dealing with the state change.(5)We consider resource locating and resource retrieval together. When the content has more than one provider, we use the provider selection algorithm. And we prove that it improves the stability and fault-tolerance of data transfers.(6)We present the design and experiment of the new model. Then we simulate and evaluate it on the NS2 platform. From the comparison results of our experiment, we have proved that the new model performs better than some models. And at the same time, the new model ensures the high hitting rate and short delay. Also, it improves the stability of transfers. So the new model worth deeply researching.