An Extension of Virtual Globe to Build On-Demand Geospatial Data Sharing Capability Using Peer-to-Peer Technology

In the virtual globe system, ever higher performance is demanded for high quality service, especially when requesting intensive data from large-scale networks, such as large scene 3D city models with fine textures. Extending the virtual globe platform from the present centralized mode into a decentralized mode can significantly improve platform capacity and service quality without additional investment in hardware, but presents new challenges such as the time cost of finding a peer, unstable offering, and low service capacity. A GeoODP2P network is designed based on specific features of spatial data transmission. Next, we discuss peer selection mechanisms that relieve the negative influence of peers, and propose a pre-fetch mechanism that takes advantage of the unique characteristics of the P2P environment. This article implements a simulation system for a GeoODP2P network and presents a prototype platform that incorporates P2P functionality. Peer selection and pre-fetch mechanisms are studied and tested on this simulation system. The prototype platform run in a real scenario demonstrates the effectiveness of applying P2P to a virtual globe platform.