A Topology Matching Method of Peer-to-Peer in the Mobile Environment

Peer-to-peer constructed on the basis of the distributed hash table don´t consider the underlying physical network topology when it build logical overlay, which lead to topology mismatch. In the mobile environment, nodes move randomly, join and leave frequently, which have exacerbated the underlying physical network topology dynamic changes, and further exacerbated mismatch between the logical overlay and the underlying physical network. This paper propose several novel strategies, which includes dividing the P2P coverage into several regions and giving the node identifiers common prefix in the same region, classifying nodes´ type according to the structure of physical network and node´s moving characteristics under mobile environment, transforming the region of the nodes which move cross-regional and making node replacement when nodes join in or withdraw. All of these enhance the degree of matching overlay network to the physical network. Performance analysis shows that the method have significant advantages in transmission delay and search resources.