BLE MIDI 1.0.pdf
This specification defines a method for encoding and decoding MIDI data for transmission over Bluetooth Low Energy (BLE) connections which enables product compatibility across all computing platforms (iOS, MacOS, Windows, and Android).

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.