  As an emerging technology with exceptional low energy consumption and
low-latency data transmissions, Bluetooth Low Energy (BLE) has gained
significant momentum in various application domains, such as Indoor
Positioning, Home Automation, and Wireless Personal Area Network (WPAN)
communications. With various novel protocol stack features, BLE is finding use
on resource-constrained sensor nodes as well as more powerful gateway devices.
Particularly proximity detection using BLE beacons has been a popular usage
scenario ever since the release of Bluetooth 4.0, primarily due to the beacons'
energy efficiency and ease of deployment. However, with the rapid rise of the
Internet of Things (IoT), BLE is likely to be a significant component in many
other applications with widely varying performance and Quality-of-Service (QoS)
requirements and there is a need for a consolidated view of the role that BLE
will play in applications beyond beaconing. This paper comprehensively surveys
state-of-the-art applications built with BLE, obstacles to adoption of BLE in
new application areas, and current solutions from academia and industry that
further expand the capabilities of BLE.
