What is Scope Query

The currently two types of main P2P technologies–unstructured and structured approaches do not care about the semantic meaning of the nodes. They do not care about the nodes whose users may take different roles in social groups in the communities. Here, a semantic P2P Network-Virtual Hierarchical Tree Gird Organizations (VIRGO) is described. VIRGO is a hybrid of unstructured P2P and structured P2P technologies by merging a multi-tuple Virtual Hierarchical Overlay Network and random cached network. It has the following properties: Decentralization--VIRGO is fully distributed, robust, and easy-managed; Load balance–Cached nodes in route table help to solve the problem of the load balance in the tree structure; Scalability--Time complexity, space complexity and message-cost of lookup protocol of VIRGO is O (logN), where N is the total number of nodes in the network; Availability–There is at least one path between every two nodes. This chapter gives audience the concepts, framework, protocols and applications about Virtual Hierarchical Tree Gird Organizations (VIRGO). It will point out why VIRGO should exist among lots of P2P technologies