RE: Matter over thread with Unicast audio server

Hieu — Fri, 11 Apr 2025 16:45:29 GMT

Hi Sivakumar128,

There are two main concerns here: memory footprint and radio time.

First let's consider the memory footprint. For simplicity, let's based on the latest SDK release, v2.9.1.

For the network core, it would be fine, since the nRF5340 supports Matter with BLE coexistence.

On the application core, the Matter template sample takes roughly 545kB of flash (including the bootloader), and 185kB of RAM.

For LE Audio, the nRF5340 Audio application takes about 560kB of flash and 142kB of RAM, no bootloader

Among them, they share the BLE Host. There is a vast feature difference between Matter (simple ACL link) and LE Audio (ISO). Let's say about 20kB of flash, 12kB of RAM.
They also share the bootloader, which takes ~30~32kB. RAM doesn't matter because it runs outside of the application
Finally, they share the Zephyr kernel which takes ~60kB of flash, 29kB of RAM.

Based on those number, we can roughly estimate that RAM requirement is within capability, but total flash required would be almost if not more than the 1024kB of available flash.

Arguably some memory optimization can be done to fit both set of features, but even then, the footprint is so large it can't be recommended for production.

As for radio time, there is also a conflict of interest between the two features. If you want the control over Matter to be responsive, then the radio should spend as much time on Thread RX as possible. However, if you want good audio quality, then the radio should spend as much time on BLE RX as possible.

In conclusion, if you want to make a product out of this, then I strongly recommend against it. If you want to make something for personal use, then it might be possible.

Hieu