Introducing Bluetooth LE Audio - Part 1: Sound of a Revolution

Following the Bluetooth Core 5.2 release, Bluetooth Low Energy Audio introduces capabilities that will revolutionize audio applications through isochronous channels and new audio middleware. Nick writes about a framework supporting bidirectional audio and shared listening in Part 1 of a two-part article.

- Nick Hunn

Most developers working with Bluetooth specifications focus on the release of the core specification. That's the foundation of Bluetooth, defining the radio, the protocols that transport data over the air, and the fundamental security mechanisms. The first release, Version 1.0, was back in 1999, when the Core included everything up to the application layer, including audio. When new applications were developed, these moved out into individual application profiles, which evolved independently over time. Significant new features in the Core resulted in new prime numbers for subsequent releases. Core 2.0 introduced enhanced data rates, potentially trebling the throughput. Core 3.0, now deprecated, allowed alternate radios, such as 802.11, to achieve higher data rates. Core 4.0 introduced the biggest innovation in 2010, adding Bluetooth LE, which introduced a redesigned radio to support much lower power applications.

Ten years later, in 2020, the release of Core 5.0 started the path to enabling audio over Bluetooth LE, with key innovations appearing in the following two releases. 5.1 brought in extended advertising, which would be key to broadcast applications, and 5.2 added isochronous channels, which enable audio transfer over a Bluetooth LE radio [1].