Location API is a fused location provider. The fused location provider is a location API in Google play services that intelligently combines different signals to provide the location information that your app needs. It manages the underlying location technologies, such as GPS and Wi-Fi, and provides a simple API that you can use to specify the required qualify of service.
You can use this feature to enhance the device’s location awareness when you turn on location and Wi-Fi scanning. It measures the distance between the phone and the Wi-Fi access point (AP) that supports RTT.
You can turn on the Wi-Fi scanning by accessing the menu -> “Settings” ->“Location” -> “Wi-Fi and Bluetooth scanning” -> “Wi-Fi scanning”.

Note: In order to protect privacy, this feature will not connect to Wi-Fi. It can only determine the distance from the AP to the device, and it can be accurate to the range of 1 to 2 meters.