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Bluetooth Low Energy (BLE) in Android Devices

“Bluetooth Low Energy, a short range, low power consuming, wireless standard adds to the Android device feature lists, offering quick connection with other BLE devices such as smartwatches, heart-rate monitors, and proximity sensors, etc.”

With the widespread use of smartphones, most of which are Android devices, Bluetooth Low Energy technology is becoming the most preferred choice of wearable devices across the world. Apart from Android devices being so prevalent, another reason for BLE technology being the go-to technology for smartwatches, Fitbits, and other smart wristbands is low power consumption.

The BLE standard was designed in 2006 as Wibree, by Nokia which was later christened as BLE when Bluetooth 4.0 standard was launched in 2009-2010. Nokia wanted to design a short-range, wireless network standard like Wi-Fi and Classic Bluetooth while keeping the power consumption to a minimum.

Many Android devices, be they smartphones wearable devices, or various IoT devices that we use in healthcare, come with built-in platform support for Bluetooth Low Energy (BLE) in the central role. The Android operating system also provides APIs (Application Programming Interfaces) that are used by applications to not only discover nearby devices but also query services as well as transmit information.

Bluetooth Low Energy and Classic Bluetooth Standard

Unlike Bluetooth classic, BLE data transmission is restricted to limited channels. Though the BLE 5.4 standard, which was launched in February 2023, allows bi-directional communication and PaWR (Periodic Advertisement with Response), the power consumption is the lowest in comparison to other short-range wireless standards.

In short, Bluetooth Classic consumes more power but provides a higher data transfer rate than BLE, which consumes low power. So, for devices that use small, non-chargeable batteries, and data transfer is low, BLE is the right technology as BLE devices, even with small coin-sized batteries can have a lifetime of 5-6 years.

How does BLE Technology Work in Android Devices?

For your BLE-enabled android-based devices to connect with other BLE-enabled devices and share data, they must first establish a connection, a channel of communication. For designing BLE applications and APIs, you must first declare several Bluetooth permissions in your apps. Specify whether your app requires Bluetooth Classic or Bluetooth Low Energy.

Subsequently, you can declare BLUETOOTH_SCAN, BLUETOOTH_ADVERTISE, BLUETOOTH_CONNECT, and ACCESS_FINE_LOCATION, as per your requirements.

Afterwards, since your app now has permission to use Bluetooth, it needs to access the BluetoothAdapter and determine the Bluetooth availability on the device. If that is the case, Bluetooth is available; the device will scan for nearby Bluetooth-enabled devices to connect.

Once a nearby device is found, a connection on the GATT server (Generic Attribute Profile) on the BLE device is established to discover the capabilities of the BLE device, using connectGatt(). Once the connection is made, data can be transferred to the connected device as per the characteristics of the device.

Bluetooth Low Energy Applications