Taxonomy caching: A scalable low-cost mechanism for indexing remote contents in peer-to-peer systems

High storage capacity and support for wireless internet is now available in an increasingly higher number of mobile devices. These devices can be connected in a P2P network, thus enabling sharing of resources (which can be both files and services) with other users participating in the network. An important challenge is to enable capabilities for finding relevant resources stored at other devices. In this paper, we present an approach to improve P2P search that is particularly suitable for connections with limited bandwidth, as in the case of portable devices. The contents of a peer are represented by taxonomy terms, and remote peers maintain a taxonomy overview instead of detailed indexing information of remote peers' contents. We show through simulations that our approach, while achieving comparable recall compared to basic flooding, significantly reduces 1) the number of messages needed for performing a query and 2) the number of peers that have to be contacted during the query.