LE Channel Sounding

LE Channel Sounding (CS) is a feature defined in the Bluetooth Core Specification. CS allows two devices in a connection to perform measurements of their communication channel, both the round trip time (RTT), and the phase and magnitude (as in-phase and quadrature (IQ) values) can be measured. The RTT and IQ values can then be sent to an application to calculate the distance between devices.

Channel Sounding currently has Experimental support in the SoftDevice Controller for the nRF54L15 SoC. CS can be enabled by building with the CONFIG_BT_CTLR_CHANNEL_SOUNDING Kconfig option enabled.

Developing with CS

Currently, the HCI UART sample is recommended to get started with Channel Sounding. Build the sample with the following command to enable the CS feature:

west build -b nrf54l15dk/nrf54l15/cpuapp --pristine -- -DCONFIG_BT_CTLR_CHANNEL_SOUNDING=y

You can use the sample to run the following supported HCI commands over UART:

  • LE CS Read Local Supported Capabilities

  • LE CS Read Remote Supported Capabilities

  • LE CS Security Enable

  • LE CS Set Default Settings

  • LE CS Read Remote FAE Table

  • LE CS Create Config

  • LE CS Set Channel Classification

  • LE CS Set Procedure Parameters

  • LE CS Procedure Enable

  • LE CS Test

  • LE CS Test End

Experimental Limitations

Currently, the following limitations apply to the Experimental support of Channel Sounding: