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Progress In Wireless World: Detailing Interesting, Forward-Thinking Recent RF Developments

Setting new horizons with a combination of radio, antenna, OS, audio and data gathering that present an intriguing picture of where things may be headed.

Almost to the day, it’s been 12 months since I resigned my role at Qualcomm, having looked after aptX for almost 30 years. In that time, I’d been on a journey that took aptX into more than 12 billion devices in the professional and consumer electronic audio sectors.

The resignation was in part down to post-Covid, in part approaching 57 years old, and an interest to see if I could go again but mostly just a sense of frustration about wireless audio. This frustration was almost wholly around Bluetooth and how it really wasn’t delivering on it’s potential.

Hit Or Miss

When APT Licensing Limited was acquired by CSR in 2010, Bluetooth audio was considered a joke from an audiophile perspective. No reputable audio manufacturer was happy with the codec at the time, i.e., SBC. Aside from audio quality, latency was so bad the Bluetooth Special Interest Group (BT SIG, which is a body set up to oversee technical progression) used protocols to achieve synchronization due to unworkable delays, for example, audio/video delay reporting and management.

However, because the SIG didn’t have a fit, for-purpose Interop program, it was hit or miss if that feature worked between different OEMs. Introducing aptX helped with a number of these problems and by the time I left, audio quality was up to CD Lossless and latency had the potential to get to 25 milliseconds (with Bluetooth LE/5.3).

Further, a robust Interop program helped ensured a consistent user experience (UX), i.e., a source device (handset, PC, dongle) purchased from Manufacturer A was going to work with a sink device (earbuds, headset, soundbar, speaker) purchased from Manufacturer B.

However, due to Bluetooth performance being driven by a small number of semiconductor companies, it meant that innovation and the UX was in the hands of a few. These few were without doubt staffed by supremely talented RF engineers, but they had little or no working knowledge of audio. The SIG was spectacularly slow-moving (which is good and bad) which all added up to something that was underwhelming.

New Horizons

Without really a joined-up plan, I left and fairly quickly got drawn into two companies and a different RF topology. The first company is AntennaWare, which came from the same stable as aptX, i.e., Queen’s University Belfast. The founders (Gareth Conway and Matt Magill) had patented new antenna techniques that address body blocking, which is a problem when streaming audio from a handset placed in the back pocket to earbuds.

The second company is Sonical, with had a plan to deliver an operating system in the ear, i.e., CosmOS. This would allow configurability at the point of use by dropping in an app as opposed to the rigid approach of whatever the semiconductor company dictated at point of build.

Finally, there’s the RF protocol called Ultra Wideband (UWB), which basically seemed pure solid gold in terms of latency and data throughput credentials. However, sometimes all that glitters isn’t gold. There was a fundamental flaw: due to the frequencies UWB employs (6.5 GHz and 8 GHz), devices suffered terribly from body blocking and detuning, which effectively ruled out wearable applications. However, this weakness is solvable with AntennaWare’s BodyWave antenna design.

Now we have an RF protocol with good power figures, sub 5 ms of latency, and enough data to support 24/96 Linear PCM audio (high res). Add in CosmOS and we could now have a headset that provided all the functionality that audiophiles and gamers would like and appreciate but the host device could be configured for high-res audio, immersive gaming, hearing assistance and general health purposes (for example, blood pressure, heart rate and monitoring).

A few months in and the good people at Segotia, which has developed an Auditory Attention Decoding (AAD) algorithm that produces NeuroMarkers, made contact and explained about their EEG technology, which can be used for attention monitoring and cognitive function awareness. With the ear being so close to the brain, inserting an earbud with sensors will readily lend itself to data gathering, which could be used a utility tool or try to improve mental health.

The applications are literally endless for this combination of radio, antenna, OS, audio and data gathering. Almost overwhelming, in fact, and maybe outlining one use case will go some way to paint a picture.

Real Progress

Live music needs low-latency radio links for both microphones and in-ear monitors (IEMs). Anything over 10 ms (mic to front of house console and then back to IEMs) will be just noticeable (especially for drummers and vocalists) but not damaging enough to affect the performers experience. It’s worth noting that 10 ms equates to around 3.5 meters, which is roughly the distance band members are usually separated from each other on a stage or in a performing area.

UWB with AntennaWare’s BodyWave can now service this fundamental requirement of low latency. The mono feed from the mic to FOH is around 4 ms, the same for the stereo send back to the musicians ears. The remaining 2 ms will be taken up with digital-to-analog (DAC) and analog-to-digital (ADC) conversion as well as processing in the console.

An occupational hazard for musicians is damaged hearing. An option is to configure IEMs for normal use, i.e., listening to their feed 99 percent of the time, while for the other 1 percent, the devices can be reconfigured to run hearing tests with the results being held in the cloud. Over a period of time the owner can record, monitor and understand if their hearing is being impaired, and based on ongoing data harvesting, adjust their lifestyle accordingly. The IEMs are tools but can now be configurable tools.

Earlier this year I ran an AES workshop in Helsinki, Finland titled “The Future of Wireless Audio, Headphone 3.0” where the guest panelists were from Qorvo (UWB), AntennaWare, Sonical (CosmOS), Segotia (EEG), MQA (Audio) and Lenbrook. The final name is really important as they are the OEM brand that has taken the leap to announce a product with all the aforementioned functionality.

It’s all very well for me to hypothesize but it needed an OEM to make it real. Bravo Lenbrook. (Slides for this workshop are available on request.)

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