A Peer-to-Peer System for Location-based Services

Location-based services promise to offer highly personalized content based on the users current geographical position. A typical example is a restaurant finder service that returns a list of restaurants in specified proximity of the users ́ current position (via GPS or mobile phone triangulation). Building the infrastructure necessary to offer competitive global location based services of different kinds can be a challenging task for an Internet or mobile phone service provider due to the amount of necessary infrastructure and information. Peer-to-Peer (P2P) systems, however, offer the possibility to deploy new services without the need for centrally managed infrastructure because they use resources available at the participating end-users' systems. In this paper, we describe a new P2P system that can be used to offer location-based service, combining the advantages of location-aware services with the low costs and good scalability properties of modern P2P systems. The system is a structured P2P system based on a novel overlay network described in this paper. The main advantage of this overlay structure is that contrary to existing DHTs it supports location-based area search in a more efficient and reliable way. As proof of concept we built a network that offers location-based search and metadata based search for webcams that are connected to our network.