The ubiquity of Bluetooth-enabled smartphones and peripherals has brought tremendous
convenience to our daily life. In recent years, Bluetooth beacons have also been gaining popularity
in implementing a variety of innovative location-based services such as self-guided systems in
exhibition centers. However, the broadcast-based beacon technology can only provide unidirectional
communication. In case smartphone users would like to respond to the beacon messages, they have
to rely on their own mobile Internet connections to send the information back to the backend system.
Nevertheless, mobile Internet services may not be always available or too costly. In this work, we
develop a real-time locating system based only on the Bluetooth low energy (BLE) technology to
support interactive communications by combining the broadcast and mesh topology options to
extend the applicability of beacon solutions. Specifically, we turn the smartphone into a beacon
device and augment the beacon devices with the capability of forming a mesh network. The
implementation result shows that our beacon devices can detect the presence of specific users
at specific locations, and then the presence state can be sent to the application server via the relay of
beacon devices. Moreover, the application server can send personalized location-based messages to
the users, again via the relay of beacon devices. With the capability of relaying messages between
the beacon devices, it would be convenient for developers to implement a variety of interactive
applications such as tracking VIP customers at the airport, or tracking an elder with Alzheimer’s
disease in the neighborhood.