Multi-Connections at same time possible on newest version of Channel Sounding for ranging Initiator/Reflector?

[NickDeLeenheer]

Hi,

I was wondering if the newest sample available in NCS3.0.1 is already capable of holding multi connections. Otherwise, for this little time that is present i will do my own implementation to connect with the boards sequentially...

Also, would it be hard to implement multiple antennas to my nRF54L15 boards? I think that multiple antenna paths would increase accuracy, since the accuracy of the distance estimation is very dependent on the specific shortest path that it found. nRF54L15 only has 1 Antenna path (i Think). And if it has more, is it easy to configure multiple antenna paths?

A last question on how to improve accuracy: Is the ifft better for inside? It uses the same phase samples as the Phase Slope method, but i was wondering how it works and where i can find the implementation, because it seems better for now. I also was wondering why it is now taking longer to get my distances with the same configuration compared to the previous version of this sample?

Kind regards,

Nick De Leenheer

[Elfving]

Hi Nick,

It's possible to run CS on multiple connections at the same time. We don't make much effort to avoid scheduling conflicts however so parameters and kconfigs have to be selected carefully. One thing to note that if you have issues with this, one usual suspect is that you haven't increased BT_CTLR_SDC_CS_COUNT.

Is your end-goal to trilaterate a position? 

Also, would it be hard to implement multiple antennas to my nRF54L15 boards? I think that multiple antenna paths would increase accuracy, since the accuracy of the distance estimation is very dependent on the specific shortest path that it found. nRF54L15 only has 1 Antenna path (i Think). And if it has more, is it easy to configure multiple antenna paths?

Could you expand a bit on what you mean by this, and "antenna paths"? EDIT: I see now that we support multiple antennas for CS much like DF. This was news to me. That is what is being referred to by antenna paths. The NRF54L15DK just has one paths, but you could connect more.

The nRF54L15DK has one antenna on it. You can however connect a different antenna on it as well. I am not so sure if something along the lines of a antenna matrix (like what you use for direction finding) would be able to improve anything here.

A last question on how to improve accuracy: Is the ifft better for inside? It uses the same phase samples as the Phase Slope method, but i was wondering how it works and where i can find the implementation, because it seems better for now. I also was wondering why it is now taking longer to get my distances with the same configuration compared to the previous version of this sample?

Not necessarily. This older webinar goes through the differences.

Regards,

Elfving

[NickDeLeenheer]

Hi,

Thank you for your input on this matter, i will look into parallel connections later.

But for now, i already succeeded in multiple connections being hold SEQUENTIALLY for my older version, i a almost succeeded in this matter using the new sample from Nordic.

I would like to get the problem that i stated in my other thread: "Ranging CS data from multiple connections", to be fixed by this Thursday, since i will be doing measurements with my thesis supervisor.

It's a problem with the fact that we don't get succesfull data steps anymore, so the distance estimates are not getting updated (data_complete) ...

If you could take a look at that thread, or if another engineer can help me with this quickly, i would be very happy.

Kind regards,

Nick De Leenheer

[NickDeLeenheer]

Hi,

I just got a working code! Thank you very murch!

Kind regards,

Nick De Leenheer

[Elfving]

Great Nick! Glad to hear it Hope your supervisor accepts you getting it a day late.

Regards,

Elfving

[Triscuit]

Hey Nick, I am also working on multi-connections. I saw that you were able to get sequential connections, I was wondering how you achieved this, is it by making a queue in the reflector to manage the connections? Right now my initiators are just connecting simultaneously, and which ever comes first connects first and the second one would sometimes be able to connect, the other times it shows "tried to parse empty step data". Sometimes they both connect, and at times they both don't connect. I believe they are competing for resources, leading to a race condition. I cannot get consistent results due to uncertain outcomes. I was wondering how you managed to get a perfect sequential order, or if you even have a simultaneous connection now. Thanks.

[NickDeLeenheer]

Hi,

Yesterday i did measurements, and i must say... it works, but it is pretty slow. And with a lot of beacons, it takes longer because of large memory being used i think. i am making an initiator who reconnects with multiple devices and i succeeded in this matter, altough it is not yet very good...

I am still looking forward on improving my code.

Kind regards,

Nick De Leenheer

[Triscuit]

Hi Nick,

I am curious about how you actually implemented the system to reconnect with multiple devices. Did you put them in a queue and make them retrieve data one by one and then dequeue after? If so did you implement a queue structure in the reflector code? I am also concerned about the memory, as I have observed, conducting multiple channel sounding procedures at once slows each one down significantly and sometimes causes one of them to stop updating completely, but I am using a free for all system where multiple initiators work all at once. Thanks for your response.

Sincerely,

Triscuit