  The Internet of Things helps to have every individual interconnected with
their surroundings and to interact with them through smart devices. In recent
years, Bluetooth Low Energy (BLE) technology has become very popular in smart
infrastructures, the medical field, the retail industry, and many more areas
due to its availability in a plethora of wireless devices. BLE is widely used
in IoT devices, such as smartphones, smart watches, and BLE beacons. Beacons
are small, low-cost, and low-power wireless transmitters that bring attention
to their location by broadcasting a signal with a unique identifier at regular
intervals. BLE beacons are a promising solution for many smart city
applications, from proximity marketing to indoor navigation. However, they do
pose security and privacy challenges. This work discusses the characteristics
of BLE beacons, the applications that can benefit from them, and the challenges
they pose while trying to identify research opportunities and future
directions.
