Cooperative Guidance System for Mobile Users Inside Large Buildings Based on Visible Light Communication

Toward supporting people's wayfinding activities, we propose a VLC-based guidance system for mobile users inside large buildings. A mesh cellular hybrid structure is chosen as the architecture, and the communication protocol is defined for a multi-level building scenario. The dynamic navigation system is made up of several transmitters (ceiling luminaries) that transmit map information and path messages for wayfinding. Each luminaire includes one of two types of controller: a "mesh" controller that communicates with other devices in its vicinity, effectively acting as a router for messages to other nodes in the network, or a "mesh/cellular" hybrid controller that communicates with the central manager via IP. Edge computing can be performed by these nodes, which act as border routers. Mobile optical receivers, using joint transmission, collect the data at high frame rates, extracts theirs location to perform positioning and, concomitantly, the transmitted data from each transmitter. Each luminaire, through VLC, reports its geographic position and specific information to the users, making it available for whatever use. A bidirectional communication process is carried out and the optimal path through the venue is determined. Results show that the system offers not only self-localization, but also inferred travel direction and the ability to interact with received information optimizing the route towards a static or dynamic destination. According to global results, the location of a mobile receiver is found in conjunction with data transmission. The dynamic LED-aided guidance system provides accurate route guidance, allows navigation, and keeps track of the route. Localization tasks are automatically rescheduled in crowded regions by the cooperative localization system, which provides guidance information and alerts the user to reschedule.