The role of caching and context-awareness in P2P service discovery

Mobile terminals (cellular phones, PDAs, palmtops etc.) emerge as a new class of small-scale, ad-hoc service providers that share data and functionality via mobile web services' calls. In mobile service discovery, it is often the case that implicit contextual information such as the location of the requestor, time the query was submitted, capabilities of the involved devices have a significant impact on query evaluation and the quality of the results. On the other hand, lack of scalability and the well-known single point of failure problem call for distribution of service directories into several peers. In this paper, we present an approach for context-aware service discovery where service directories reside in a P2P architecture. We explore the role and benefits of context-awareness and caching query results in the service discovery process. We conduct extensive experiments coming up with guidelines for service directory design in a P2P context.