Bluetooth Low Energy (BLE) is a wireless connection specification supported by the majority of mobile computing devices. BLE (also called Bluetooth SMART) can extend battery life for mobile devices using connected accessories (such as MIDI keyboards and controllers) that don't continuously stream data.
An MMA Working Group evaluated Bluetooth LE MIDI performance (latency and jitter) and decided on a specification for MIDI over Bluetooth which would enable products from different manufacturers to interoperate. The Specification for MIDI over Bluetooth Low Energy (BLE-MIDI) is based on Apple's implementation which appeared in iOS8 and OSX 10.10, so that products from early adopters would remain compatible with the industry standard.