nRF 5340 Audio DK - PHY coding

RE: nRF 5340 Audio DK - PHY coding

SwRa — Wed, 10 May 2023 12:25:05 GMT

Hi Joe,

For information regarding roadmap and future plans, You will need to get in touch with your Regional Sales Manager.

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

JoeBakalor — Wed, 10 May 2023 12:23:30 GMT

Thanks, Swathy. Do you know if it’s on the roadmap?

RE: nRF 5340 Audio DK - PHY coding

SwRa — Wed, 10 May 2023 11:08:34 GMT

HI Joe,

We support only 1M and 2M PHY for PCFT controller.. So no, Coded PHY is not supported.

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

JoeBakalor — Mon, 08 May 2023 19:52:37 GMT

Hi SwRa , what about support for Coded PHY in BIS mode?

RE: nRF 5340 Audio DK - PHY coding

SwRa — Wed, 03 May 2023 13:18:42 GMT

HI Lars,

I heard back from the developers.. This is what they said:

"Following are details of PHY in CIS demo:

In NCS v2.3.0, ADV-EXT is used for headset advertisement, so once if gateway connected with a headset, the ACL will use 2M PHY as default. User can try to send PHY update from either side for changing the PHY for ACL to 1Mbps for a trial.
For PHY in ISO, that is decided by gateway, and it is 2M in the default setting.
In the current code, the gateway will use a preset configuration for codec and QoS setting, which is in here
https://github.com/nrfconnect/sdk-nrf/blob/8f26142b2f815d5a12e1f77ee8a6ea554a89b079/applications/nrf5340_audio/src/bluetooth/le_audio_cis_gateway.c#L93

However, if we trace the code a little further bit, we will find the PHY is fixed in here:
https://github.com/nrfconnect/sdk-zephyr/blob/74c7bca86e6a7d590333681eef90e159d79bcfe8/include/zephyr/bluetooth/audio/audio.h#L373
So customer can try to create a preset by self (that would be better), or do a quick trial to modify the above line for assigning the PHY to 1Mbps (not suggested)
Please note that
a. We are focusing on using 2M PHY in ISO CIS, we are not well tested other options
b. Coded PHY might not work properly, we haven't tested that, and that is not covered in the contract
c. 1M PHY means slower than 2M PHY, so we cannot use the same bitrate anymore because of the bandwidth.
(CONFIG_BT_AUDIO_BITRATE_UNICAST_SINK=32000, which means 40 bytes per frame works for 1M CIS ISO)"

Hope this helps.

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

Lars.Bjok — Tue, 02 May 2023 10:22:08 GMT

The aim is to test the CIS mode over the different PHY settings.

Since the LE codec is seperate from the physical layer in the BLE stack i dont see why it would not work to switch between the different configurations. Any future updates for the Audio application planned to improve these features?

Regards,

Lars

RE: nRF 5340 Audio DK - PHY coding

SwRa — Thu, 27 Apr 2023 09:40:51 GMT

HI Lars,

Do you want to test the application in CIS mode or BIS mode? I am checking with the developers if it is indeed as Paal has mentioned in the previous reply and any additional information would be helpful.

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

PaKa — Mon, 24 Apr 2023 14:16:20 GMT

Does Bluetooth LE Audio allow you to use any other PHY than the 2Mbps? It would consume a lot of the bandwidth available so inclined to believe this won't be Bluetooth compliant.

RE: nRF 5340 Audio DK - PHY coding

SwRa — Mon, 24 Apr 2023 13:02:29 GMT

Hi Lars,

The Audio application uses extended advertisement.. It uses 2M PHY by default.. So if you want to change the PHY, you will first need to disable extended advertising and add legacy advertising and then change the PHY for it.

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

Lars.Bjok — Thu, 20 Apr 2023 14:36:48 GMT

Yes i understand that power efficency might be different. I want to change the PHY - configuration to test if the range that audio can be transmitted in the different configs between the 2M, 1M 500kbps and 125kbps. I dont see why you would keep these changes locked for the application.

I want to know if it's possible to change the to the different PHY - settings and if it's possible how would i do it on the nRF5340 Audio DK.

Regard,
Lars

RE: nRF 5340 Audio DK - PHY coding

SwRa — Thu, 20 Apr 2023 10:58:42 GMT

Hi Lars,

Sorry for the delay..

The default for the Audio application is 2M PHY. You would loose half the bandwidth by going to 1 M PHY - it would also cost more power, since it takes longer (more radio time) to send the same message in 1 M PHY compared to 2 M PHY. Could you tell me why you need to change the PHY.?

Regards,

Swathy

RE: nRF 5340 Audio DK - PHY coding

Lars.Bjok — Thu, 20 Apr 2023 07:25:37 GMT

Hello Swathy!
I was wondering if there was any update about the PHY coding?

RE: nRF 5340 Audio DK - PHY coding

SwRa — Fri, 14 Apr 2023 13:30:23 GMT

Hi Lars,

Letting you know that I am looking into it.. I will get back to you with an update on Monday.

Regards,

Swathy