how to configure Channel sounding Security level 3,4 on the host?

[Shreeyash17]

ticket link
I have reviewed an existing thread and learned that when using Main Mode 1 or 3, the Channel Sounding Security Level is set to Level 2. For other modes, it defaults to Security Level 1.

Given that the controller does not support 10ns CSS RTT accuracy, I attempted to configure Security Level 3 and 4 by using:

• Main Mode 2 with Sub Mode 3, and

• Main Mode 3 with Sub Mode 2

in the Create Config command. The host receives error code 0x211 (Unsupported Feature or Parameter Value).

My question is:

     1 . Is this the correct approach to attempt to configure Security Levels 3 or 4, knowing that the controller does not support 10ns RTT?

     2 . Is this the error the host needs to expect from the controller?

If this is not the correct practice, then:

• What is the proper way to request Security Level 3 or 4, even if unsupported?

• Are there any other valid Main Mode/Sub Mode combinations or approach I should use for this purpose

[Menon]

Hello,

Please refer to the Sounding Security section(10.11.1) in the documentation and check the supported capabilities. As you can see, the SoftDevice Controller does not support 10ns RTT accuracy or NADM, and therefore Security Levels 3 and 4 are not supported.

in the Create Config command. The host receives error code 0x211 (Unsupported Feature or Parameter Value).

Are you using CONFIG_BT_CTLR_SDC_CS_STEP_MODE3=y, and is there any typo in the error code you have shared? 

Kind Regards,

Abhijith

[Shreeyash17]

Thank you for the response.

Menon said:

is there any typo in the error code you have shared? 

Yes you are correct.it is 0x11 (Unsupported Feature or Parameter Value error). and I have not made any changes to CONFIG_BT_CTLR_SDC_CS_STEP_MODE3.

One thing I didn’t mention earlier is that I am using an external host.

 Menon Could you please help me with the questions I raised earlier.

Given that the controller does not support 10ns CSS RTT accuracy, I attempted to configure Security Level 3 and 4 by using:

• Main Mode 2 with Sub Mode 3, and

• Main Mode 3 with Sub Mode 2

in the Create Config command. The host receives error code 0x211 (Unsupported Feature or Parameter Value).

My question is:

     1 . Is this the correct approach to attempt to configure Security Levels 3 or 4, knowing that the controller does not support 10ns RTT?

     2 . Is this the error the host needs to expect from the controller?

If this is not the correct practice, then:

• What is the proper way to request Security Level 3 or 4, even if unsupported?

• Are there any other valid Main Mode/Sub Mode combinations or approach I should use for this purpose

[Elfving]

Closing as this is addressed in 349316

Regards,

Elfving