Peer-to-peer searching mechanisms for location-aware contents with time-dependent importance

Recently, peer-to-peer (P2P) networking has become popular, and is being expected as a content sharing platform for ubiquitous networking. In ubiquitous networking, the notions of location and time are essential. Although some location-based P2P networks have been proposed, they only consider locations, and the notion of time has not been considered. In this paper, we propose P2P searching mechanisms for location-aware contents with time-dependent importance, which enables us to retrieve contents with high importance in time period specified in a query. The proposed mechanisms are based on a location-based P2P network, and each peer establishes additional links to peers within n-hops. Each peer also manages a link table, which records location and time-dependent importance of contents that its linked peers hold. Using the link table, a time-specified query is forwarded selectively to neighboring peers. Simulation results show that the proposed mechanisms enable us to search contents with high relevance while keeping network traffic low.