Reset the channel sounding parameters after a disconnection

[Vinayaka KS]

Hi, I am trying to sound two reflectors from a single initiator, and since the CS works on a one-to-one ACL system, I wanted to know how I can reset the CS-related stuff in the code. I did try this without reboot, the data becomes stagnant after a reconnection or when I connect 2 reflectors (not sound, but just connect)  

The sample provided by Nordic does a soft reboot, so it works flawlessly. I am trying to take a different path of not connecting to both of my nodes at once and do a soft reboot every time I wanna switch the sounding, but I wanted to know if a manual reset was possible for the CS params and buffer, so that I can continue with sounding another device without doing a soft reboot.

[Edvin]

Hello,

Where is "Data from Reflector 1" printed from? I couldn't find it.

I was able to reproduce it, yes. I am discussing this with our channel sounding team. I will get back to you as soon as I know more. I am sorry for the delay.

Best regards,

Edvin

[Vinayaka KS]

It's printing over the UART, and it's getting generated in the reflector and sent via NUS. 

And thanks for the update.

Regards,

Vinayaka KS

[Vinayaka KS]

Hi Edvin,
This works as intended on v3.2.2.

I tried to test it on v3.1.1, and it had build issues. I might have to port my existing code to the new version of NCS.

Regards,
Vinayaka KS

[Edvin]

Hello,
Yes, I see that this doesn't build out of the box with v3.1.x, but it builds for v3.2.x. There are some API changes to the changes in the channel sounding API.

It was our Channel Sounding team that suggested that I used 3.2, because they were not sure it would work with multiple connections in v3.1.x. 

They also suggested to have a look at this:

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrfxlib/softdevice_controller/doc/scheduling.html#channel_sounding_timing

But that document doesn't exist for NCS v3.1.x.

Best regards,

Edvin

[Vinayaka KS]

Thanks for the information, Edvin.
Now I see that the problem of mismatch and disconnection actually lies in the scheduling of the events. I will port to v3.2.2

Regards,
Vinayaka KS

[Application Ninja]

I know it's not correct to comment another persons thread, but I am commenting directly on this sample here...

So for this two connection example, it really doesn't scale well, due to the large buffer requirements of  latest_local_steps_storage and latest_peer_steps_storage.

How can Channel Sounding be effectively used to support 100's of connections then?

[Edvin]

I am not sure channel sounding is the best option if you plan to support 100's of connections. Bluetooth Low Energy even without channel sounding is challenging to maintain that many connections (probably impossible). 
You can read about the scheduling in the link in my previous reply. 

One option is probably to reconnect/disconnect whenever you change the device, but it will not be as fast, so you will not be able to get channel sounding data from all 100 devices that often. It depends on the use case. For tracking location in a storage, it might be fine, but not for real time locationing of a lot of devices. 

Best regards,

Edvin