Packetcraft just announced a Bluetooth Low Energy Audio (LE Audio) solution certified by the Bluetooth Special Interest Group (Bluetooth SIG).

This is significant in that Bluetooth for audio has for many years used the SBC audio codec, which is not considered suitable for high-definition audio.  “LE Audio,” as defined by the Bluetooth SIG, uses a new codec called LC3 for higher quality audio.  A codec compresses and encodes the audio in the digital domain, lowering the bit rate and power consumption with as little loss in audio quality as possible.  LC3 offers superior audio quality compared to SBC even at roughly half the bit rate of SBC.

SBC stands for Low-Complexity Sub-Band compression and encoding.    SBC is open source and is obligatory for Bluetooth devices that use the A2DP profile (Advanced Audio Distribution Profile), which specifies how high-quality audio signals are transferred via Bluetooth.

Since the advent of Bluetooth for audio, many companies have come out with proprietary encoders that can provide better quality audio over Bluetooth at the same or even lower bit rates and lower power consumption than SBC.  These codecs are not standards-based and interoperability among manufactures’ devices is not guaranteed.  Some of the most well-known of these codecs:

• Qualcomm’s aptX, including aptX HD, aptX LL, and aptX Adaptive.  Qualcomm offers aptX as part of its Qualcomm Snapdragon Sound for mobile phones, earbuds, wireless headphones, and other audio devices.
• Apple’s AAC.
• Sony’s LDAC.
• Samsung’s SSC.

The new LC3 codec improves on the older SBC, and compares favorably to proprietary codecs such as AAC, aptX, and LDAC, as shown below.  In addition, LC3 is an open source standard specified for Bluetooth LE Audio.   Fraunhofer IIS and Ericsson developed LC3 to Bluetooth SIG specs.

 

Audio quality can be quite subjective of course.  To read more about audio codecs and audio quality, I recommend this guide (no affiliation to the author).  You can see some comparisons of LC3 and SBC on the Bluetooth SIG website here.

Packetcraft, founded in 2019 by an executive management team with experience at Arm, Wicentric, Cambridge Silicon Radio, UWB pioneer Staccato Communications, and Texas Instruments, specializes in easy to embed protocol stack and link layer software for Bluetooth and UWB chips. 

The company’s Bluetooth LE Audio solution includes:

• Packetcraft Host - Bluetooth 5.3 host stack with profiles for LE Audio.
• Packetcraft Controller - Bluetooth 5.3 link layer with isochronous channels, optional 802.15.4 MAC, AoA and AoD direction finding capabilities, full access to open source code.
• Packetcraft LC3 - Bluetooth LC3 codec for LE Audio.

The Packetcraft LE Audio solution is used on the Nordic Semiconductor nRF5340 Bluetooth SoC, which features two Arm®. Cortex®-M33 processors. 

Reducing the power consumption of Bluetooth devices allows designers to use smaller batteries and design smaller devices.  The LC3 codec also enables the Bluetooth SIG’s “Auracast Broadcast Audio” to support streaming to multiple users simultaneously.   These two features, lower power consumption and allowing people to share Bluetooth audio streams, will help the Bluetooth market grow over the next five years well beyond this year’s 5 billion devices predicted by Strategy Analytics.

You can read more about Bluetooth by visiting the Strategy Analytics Bluetooth Device Tracker pages, which includes a recent report on TWS (true wireless stereo) headset shipments here.