Most Bluetooth audio devices on the market today are based on Bluetooth classic (BR/EDR) audio profiles such as the Advanced Audio Distribution Profile (A2DP) and the Hands-Free Profile (HFP). A2DP is commonly used for high-quality audio transmission, such as for music playback, while HFP is used for voice calls and other types of audio transmission requiring less fidelity.
A2DP allows for the transmission of two-channel stereo audio and is commonly used for music playback and other applications where high-quality audio is required. A2DP uses the AVDTP protocol to transport audio data between devices and relies on other Bluetooth profiles, such as the Audio/Video Remote Control Profile (AVRCP), to handle control and signaling functions.
A2DP transmits high-quality audio with a bit rate of up to 352 Kbps (thousand bits per second) and a sampling frequency of up to 48 kHz (thousand cycles per second). So that all devices can communicate the standard specifies that SBC ( low complexity Sub Band Code) be the minimum support audio compression algorithm. At the highest bit rate, the audio experience is closeto CD-quality audio. A2DP is supported by Bluetooth-enabled audio devices, including smartphones, tablets, and laptops, as well as many Bluetooth audio devices, such as headphones and speakers.
Cloud2GND has extensive experience with classic Bluetooth audio (e.g., A2DP, Hands-Free) and ensuring products interoperate to provide outstanding user experiences. We know how to develop optimized audio solutions and troubleshoot complex issues. Through our semiconductor and stack partners we can offer licenses to multiple different audio stacks and solutions to jump-start product development.
Our latest focus is the newly released Bluetooth LE Audio profiles and specifications, which are in the process of revolutionizing Bluetooth audio.
The new Bluetooth LE Audio profiles are based on a new controller-layer feature called Isochronous Channels (ISOC). ISOC was introduced in the Bluetooth 5.2 specification and allows for the transmission of one or more fixed-rate data streams with low latency and minimal jitter, making it ideal for applications such as high-quality wireless audio. Isochronous Channels can be connection oriented (CIS) or broadcast (BIS), which can be sent to one or more devices. This new architecture opens up a wide range of previously difficult use cases such as wireless stereo with two independent devices for the left and right channels and the use of broadcast transmissions to an unlimited number of receiving devices.
The new broadcast capability, under the Bluetooth SIG’s new Auracast™ brand, is a completely new way to deliver audio using Bluetooth. It opens up a range of new use cases such as delivering one or more streams of audio to hear aids and other hearing-assistance devices (hearables), providing audio streams to “unmute” the video displays often found in public spaces, and providing context-aware audio streams in a range of public, private, and commercial spaces. In addition, by embedding multiple streams into an environment, different languages or special audio streams can be offered to meet a particular user’s needs.
The new LE audio profiles are built on top of the capabilities offered by the lower-layer controller features, such as Isochronous channels, and defines how devices that support the new audio features discover, connect with, configure, control and interact with each other. Lower-layer LE audio profiles provide the building blocks on which use-case-specific top-layer profiles are built.
The new LE audio specifications also introduce a new high-efficiency codec called LC3. The LC3 codec replaces the legacy Subband Codec (SBC) used by traditional Bluetooth classic A2DP and wideband HFP audio, and offers higher perceived quality and lower power consumption than SBC for any given bitrate. LC3 support is mandatory for the new LE audio profiles and is licensed royalty-free when used as part of a qualified Bluetooth solution.
Cloud2GND has been working with the Bluetooth Isochronous Channels feature and LE audio profiles since before their adoption. Cloud2GND is uniquely positioned to create LE-audio-based products leveraging our unequaled experience:
Our combined knowledge and experience uniquely qualifies us to help our clients transition to this new generation of Bluetooth technology which will open up many promising new use cases and opportunities.