Terrain data peer-to-peer storage model

In order to enhance terrain data network service performance, P2P technology is gradually used in large scale terrain data roaming system. It is vital to research on how to construct terrain data peer-to-peer (P2P) storage model according to its features. In this paper, we present a terrain data P2P storage model according to the pyramid model. In our terrain data P2P storage model, terrain data is organized as multi-resolution pyramid model based on multiple of 2, and data blocks among different levels are denoted in quad tree structure. Furthermore, system structure based on the P2P storage model is logically divided as three layers: terrain data server layer, terrain data service layer and terrain data download layer. Terrain data server layer is composed of data servers in traditional C/S model, and its main function is not directly to provide download service to terrain data users, but to manage, distribute and update terrain data in the system. Terrain data service layer is composed of part of clients in traditional C/S model, and its main function is to provide data search service and maintain terrain data download layer. Terrain data download layer is composed of another part of clients in traditional C/S model, and its main function is to store terrain data and provide data download service each other. From the primary test of this model, we find that the terrain data can be downloaded from more than a node so that the download speed is greatly accelerated using the terrain data P2P storage model, which can realize the massive data transmission at the lower cost compared with the single broadcast.