The wide area differential GNSS can be used to improve the accuracy, credibility and integrity of the navigation by broadcasting augmentation messages for receivers of the covering areas through geostationary earth orbit (GEO) satellites. But in cities with more building obstacles or in rooms, it is unable to realize the high accurate navigation. The way that the navigation augmentation messages are broadcast through internet has its unique advantages. The configuration and the network structure of internet-based wide area DGNSS (IBWD) are designed in this paper. According to node heterogeneity, the nodes that would join IBWD are classified into differential node types including proxy nodes and general nodes. The hierarchy mix multicast system based on node heterogeneity is constructed by the combination of application layer multicast where IP route information table is applied and i3 multicast. The results of simulation show that IBWD allows nodes to leave and join dynamically, and it is highly robust against failures. IBWD allows real time communication and the throughput of server is lower than other systems, so it can well meet the need of applications of large scale and real time broadcasting for the augmentation messages of GNSS through internet.