How to determine channel sounding security level

[Shreeyash17]

How to check CS procudure used by controller in BLE Channel sounding security I am refering to this ticket so i have questions related to it that 

I have tried to find answers of below questions in samples of channel sounding but could not find in the samples.

1. What parameters must the host set(in which command) to ensure that the controller operates with 150ns CSS RTT accuracy and 10ns CSS RTT accuracy?

2. Which parameter(along with command) determine or distinguish whether the host is setting Channel Sounding Security Level 1, 2, 3, or 4 and for these parameters which values must be assigned for each Channel Sounding Security Level  ?

3. Does the controller generate any event that informs the host which Channel Sounding Security Level is currently being used?

4. If the controller does not support 10ns RTT accuracy, what HCI error code will it return to the host when the host attempts to configure parameters that require 10ns RTT? Additionally, after this error is returned, does the channel sounding procedure continue, or does it get stuck at that point?
   
   
   

[Edvin]

Hello,

You can look at the file ncs\zephyr\samples\bluetooth\channel_sounding\src\connected_cs_initiator.c.

In the main.c, it uses first:

err = bt_conn_set_security(connection, BT_SECURITY_L2);

and then later:

err = bt_le_cs_security_enable(connection);

So these are a bit different from a normal BLE service.

Both of these are waiting for callbacks using their respective semaphores:

security_changed_cb()

and

security_enable_cb().

The first one contains a parameter saying what security level it has.

Have you tested this sample? 

Best regards,

Edvin