A Semantic Location Service for Pervasive Grids

Grid computing environments have recently been extended with Pervasive computing characteristics leading to a new paradigm, namely the Pervasive Grid Computing. In particular, QoS of existing Grid services is being augmented by means of location-awareness. This paper presents a location service that locates active mobile objects, such as Wi-Fi enabled devices and RFID tagged entities, in a real Pervasive Grid. The key feature of the service is the use of ontologies and rules to define a uniform, unambiguous and welldefined model for the location information, independently from the particular positioning system. Moreover, the location service performs logic and reasoning mechanisms both for providing physical and semantic locations of mobile objects and for inferring the finest granularity for location information in the case a mobile object is located by more than one positioning system. The service has been developed at the top of the standard OGSA architecture.