VoIP support for nRF91x LTE Modules

[4HERE_Corp]

Hello, 

Is there any documentation on setting up VoIP on the nRF91x module with Zephyr?

As the nRF91x does not have a built-in VoIP app layer, I can assemble the hardware and software pieces to address this.  In order to proceed in the correct direction, I would like to know if Nordic has any documentation/ref designs that discuss; 1. audio drivers, 2. Voice Codecs, 3. VoIP protocol stack such as PJSIP.

Thanks

Gerard

[Benjamin]

Hi Gerard,
The nRF9151 SiP is not designed for VoIP. It targets lower data-rate use cases. It may be possible to make it work over LTE-M with an efficient codec, but neither Zephyr nor our SDK provides support for VoIP or audio streaming over cellular. We use the LC3 codec for BLE Audio but I guess you will find a more suitable open source codec.

Best regards,
Benjamin

[EAB]

I just wanted to add a comment here. VoIP calls on LwM2M IoT have been proven successful by several operators. For example, ~1-2 years ago there was a very nice PoC by Vodafone, and they rarely do original work, so was likely based on some other projects. I don't recall on which tech it was, but could in theory be applied also to NB-IoT if the DM provider conforms to the full LwM2M v1.2 and DTLS 1.3.

Sorry, I don't have any links.