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

摘要

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.