Globase.KOM - A Peer-to-Peer Overlay for Fully Retrievable Location-based Search

Location based services are becoming increasingly popular as devices that determine the geographical position got more available to the end users. The problem of existing solutions to location-based search, e.g. in car navigation systems, is keeping information updated because of centralized maintenance at specific times. Therefore, retrieved results do not include all objects that exist in reality. A peer-to-peer approach can easily overcome this issue as peers are responsible for the information users are searching for. Unfortunately, current stateof-the-art overlays cannot fulfill the requirements for efficient and fully retrievable location-based search. In this paper we present Globase.KOM, a hierarchical tree-based peer-to-peer overlay that enables fully retrievable area search, lookup, and finding the geographically closest node. Simulation results prove that the overlay operations of Globase.KOM are highly efficient, fully retrievable, and logarithmically scalable. Protocol overhead and load of the peers in the overlay have been evaluated as well.