Subject / Author / Abstract
BeDIPS A Building/environment Data Based Indoor Positioning Service
J. W. S. Liu, E. T. H. Chu, J. M. Ho, L. J. Chen, S.-W. Bai, Y.-C. Chen, Y.-J. Lin, & J. Su
Despite years of efforts of research communities and industry on indoor position/location technologies and services, there is still no clear winner and no common standard today. By and large, existing indoor positioning services/systems (IPS) are not well suited for large public buildings/facilities such as train stations, airports, major hospitals, department stores, sports centers and theater complexes. Common characteristics of such buildings include complex and dynamic operating environment, large/fast fluctuations in density of people, criticality of IPS during emergencies and diversity in capabilities of user devices. Existing IPS do not address these challenges well enough to be easy to deploy and maintain, stay scalable in response to orders of magnitude surge in location queries, degrade gracefully to be disaster resilient, and minimize requirements of user devices to use the service.
This report describes an IPS, called BeDIPS (Building/environment Data-based Indoor Positioning Service). It is designed to meet these high-level requirements of IPS for large public buildings. As its name implies, the service relies on a building and environment data/information cloud (BeDIC), which among other types of data, contains 3D coordinates and geometric models of every object of interest. In particular, it contains the coordinates of location beacons (called LBeacons), which the service uses to deliver location information to users. Basically, Lbeacons are a low-cost, Bluetooth Smart Ready device. At deployment and maintenance times, the 3D coordinates of every Lbeacon are retrieved from BeDIC and stored locally. Once initialized, each Lbeacon broadcast its coordinates to HereUAre, a simple messaging application on Bluetooth enabled mobile device nearby. Interferences among Lbeacons are minimized by partitioning the network of Lbeacons into subnets and having beacons in each subset transit in a time division multiplex manner. From the coordinates of all Lbeacons heard by the HereUAre on a device, the application can easily, and sufficiently accurately, estimate the coordinates of the device when the network of Lbeacons are sufficiently dense and well placed. The report presents the architecture and design of BeDIPS and discusses reasons for its feasibility.