A distributed framework for location sensing systems

Location sensing systems became very popular and widely used in the recent years. Many places are already equipped with a great variety of location sensing hardware running specifically tailored software to use it. According to their focused nature, different systems are incompatible to each other. The development of a highly available, context-aware location service raises the challenge of integrating a large quantity of location sensing systems, consequently the service complexity increases. In order to maximize the usefulness and flexibility of already existing location sensing systems as well as to enable a service development separated from special positioning issues, we take advantage of a modular, 4-layered framework design, which hides the specific details of the location sensing system. The client-server architecture ensures that even clients with limited processing power and/or storage capacity are able to participate in the system. The framework features an abstract uniform access to the variety of sensors managed by "Location Servers" 1 and a model of hierarchal zones to describe maps of the environment. Location Servers communicate with each other to exchange information about maps and tracked objects, allowing clients to roam between different location systems. Sensor fusion enhances the accuracy and positioning probability.