nRF54L Channel Sounding on iOS 27 Beta

RE: nRF54L Channel Sounding on iOS 27 Beta

Edvin — Tue, 23 Jun 2026 08:26:13 GMT

Hello,

It would be interesting to try it out. Would it be possible to share the application that you used on the nRF in your video?

Best regards,

Edvin

RE: nRF54L Channel Sounding on iOS 27 Beta

Jose Marcelino — Mon, 22 Jun 2026 23:20:30 GMT

iOS27 Beta 2 came out and now my readings work! It's not necessary to wait for the Nordic app, it works with system APIs on iOS.

I posted a video a on X about my first experiences: x.com/.../2069196779988353135

Next up is using both antennas on the Tag. Currently it uses just one, I just got the Tags on Friday :-P

Would anyone be interested on a longer post blog style about what I did?

RE: nRF54L Channel Sounding on iOS 27 Beta

Edvin — Thu, 18 Jun 2026 08:00:40 GMT

Thank you for letting us know about your post.

Just to clarify some expectations. Our app will most likely not support iOS until CS is officially supported (not limited to Beta). This means that we will not have support for it (in our nRF Toolbox app) before iOS27 is released, earliest.

Best regards,

Edvin

RE: nRF54L Channel Sounding on iOS 27 Beta

Jose Marcelino — Wed, 17 Jun 2026 18:44:23 GMT

Reassuring news, Apple replied and it's a known issue. Fingers crossed it will work in the next beta.
https://developer.apple.com/forums/thread/834996

RE: nRF54L Channel Sounding on iOS 27 Beta

Edvin — Wed, 17 Jun 2026 09:26:04 GMT

I understand. I don't know what this app actually looks for. But yes, I checked with our mobile apps team, and they are working on support in our nRF Toolbox app. But unfortunately, we do not have a timeline for when it is ready. But if you download the nRF Toolbox app, and look out for updates, I assume it will come eventually.

Best regards,

Edvin

RE: nRF54L Channel Sounding on iOS 27 Beta

Jose Marcelino — Tue, 16 Jun 2026 15:22:38 GMT

Thank you very much for looking into this. Yes it's new but also exciting for a lot of people - fingers crossed it works very well with a dual antenna design like the new nRF54L15 Tag.

Regarding the ipt_reflector sample: I actually started there! However, iOS completely ignores the ipt_reflector device—it doesn't even show up in the sample app as a pairable/connectable device.

I believe this is because ipt_reflector doesn't advertise or host the RAS (Ranging Service) GATT service. It seems Apple's OS strictly requires the RAS service to be present in the advertising packets/GATT server before it will even attempt to initiate a connection and start the CS procedures.

To get around this, I took the Inline PCT configurations from the ipt_reflector sample (the CONFIG_BT_TRANSMIT_POWER_CONTROL, CONFIG_BT_CTLR_EXTENDED_FEAT_SET Kconfigs, and the bt_le_cs_set_default_settings call with max_tx_power = BT_HCI_OP_LE_CS_MAX_MAX_TX_POWER) and merged them directly into the ras_reflector sample.

This hybrid approach is actually what allowed me to get the results I shared:

iOS sees the RAS service and connects.
The controller negotiates Inline PCT successfully (cs_enhancements_1: 1).
The Apple PacketLogger HCI trace confirms valid Tone PCT[1] I/Q data is being received over the air.
The T_FCS_time_us successfully negotiates to 100 µs.

Since the RAS GATT service is present, the CS config is accepted, and the Inline PCT radio data is flowing perfectly over the air, I'm a bit stuck on why iOS is silently discarding the distance calculation.

I'll check in with Apple on it, if any news comes up on that side will share it here. Thanks again.

RE: nRF54L Channel Sounding on iOS 27 Beta

Edvin — Tue, 16 Jun 2026 12:42:21 GMT

Seems like we don't have much to show for yet. We are working on getting support for this in the nRF Toolbox app (Apple link), but it is not ready. We are waiting for some testing, and unfortunately, I don't have a timeline for when this will be ready at this point in time.

You did mention that you were using the ras_reflector sample. However, the "inline PCT" feature seems pretty central for the iOS support. Since you are at the 3.3.1 tag, perhaps you can test the ipt_reflector sample instead.

Best regards,

Edvin

RE: nRF54L Channel Sounding on iOS 27 Beta

Edvin — Tue, 16 Jun 2026 11:57:19 GMT

Hello,

This is news to me. I was not aware that Apple announced Channel Sounding support in iOS27. Let me look into it, and I will get back to you.

Best regards,

Edvin