Bluetooth Location Services Version 11.1.0 - Release Notes (Jun 23, 2026)#

The Real-Time Locating (RTL) library contains features for high accuracy distance estimation, Angle of Arrival / Departure estimation and spatial positioning. The software library comes with a C-programming language API for ARM Cortex M33, Windows (x86_64) and Linux (ARM Cortex A, x86_64) hosts.

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Release Summary#

Key Features | API Changes | Bug Fixes | Chip Enablement

Key Features#

Added new RTL Service component (rtl_service) providing a unified, thread-safe API for RTOS and bare-metal environments.
Added sl_rtl_get_lib_version() function to retrieve the RTL library version.
Renamed algorithm mode enums with backward-compatible defines.
Improved PBR distance measurement accuracy for SL_RTL_CS_ALGO_MODE_STATIONARY.

API Changes#

Added RTL Service APIs for context and instance lifecycle, configuration, and result queries.
Added sl_rtl_get_lib_version() function.
Modified sl_rtl_util_validate_bluetooth_cs_channel_map to add sub_mode parameter.
Old sl_bt_cs_ APIs now return error when running in RTOS mode.

Bug Fixes#

Removed maximum distance limitation of 40 m for PBR estimation in SL_RTL_CS_ALGO_MODE_TRACKING_ACCURACY_OPTIMIZED.
CS API now returns error for unsupported submode and channel map combinations.

Chip Enablement#

None.

Key Features#

New Features | Enhancements | Removed Features | Deprecated Features

New Features#

Real-Time Locationing Service#

The RTL Service (rtl_service) is a new software component providing a unified API that works in both RTOS and bare-metal environments.

The service automatically adapts: in RTOS mode it runs a dedicated processing task; in bare-metal mode it processes within the application main-loop.
All API functions can be called from any task or interrupt context. The service handles mutual exclusion internally.
Submit CS or Ranging Service (RAS) procedure data and receive distance estimates asynchronously through a result callback.

RTL Library Version Function#

A function sl_rtl_get_lib_version() was added to return the exact library version.

Algorithm Mode Enum Renaming#

The enum sl_rtl_cs_algo_mode field names have been renamed as follows:

SL_RTL_CS_ALGO_MODE_REAL_TIME_BASIC renamed to SL_RTL_CS_ALGO_MODE_TRACKING_ACCURACY_OPTIMIZED
SL_RTL_CS_ALGO_MODE_REAL_TIME_FAST renamed to SL_RTL_CS_ALGO_MODE_TRACKING_LATENCY_OPTIMIZED
SL_RTL_CS_ALGO_MODE_STATIC_HIGH_ACCURACY renamed to SL_RTL_CS_ALGO_MODE_STATIONARY

Backward-compatible defines are provided for existing code. Additionally, SL_RTL_CS_ALGO_MODE_INVALID has been added.

Enhancements#

Improved PBR Distance Measurement Accuracy#

PBR distance measurement accuracy has been improved for SL_RTL_CS_ALGO_MODE_STATIONARY.

Removed Features#

LOW Preset Channel Map Removed#

The LOW preset channel map has been removed. Attempting to configure RTLLib with LOW channel map preset will result in an error during estimator creation.

Deprecated Features#

None.

API Changes#

New APIs | Modified APIs | Removed APIs | Deprecated APIs

New APIs#


New API Signature	Deprecated API replaced by this
sl_rtl_get_lib_version()	N/A
sl_rtl_service_init_cs()	N/A
sl_rtl_service_deinit_cs()	N/A
sl_rtl_service_create_cs_instance()	N/A
sl_rtl_service_destroy_cs_instance()	N/A
sl_rtl_service_set_cs_algo_mode()	N/A
sl_rtl_service_set_cs_mode()	N/A
sl_rtl_service_set_cs_params()	N/A
sl_rtl_service_create_cs_estimator()	N/A
sl_rtl_service_set_cs_estimator_param()	N/A
sl_rtl_service_process_cs()	N/A
sl_rtl_service_process_ras()	N/A
sl_rtl_service_get_cs_distance_estimate()	N/A
sl_rtl_service_get_cs_distance_estimate_confidence()	N/A
sl_rtl_service_get_cs_distance_estimate_extended_info()	N/A

Modified APIs#


Old API	Modified
sl_rtl_util_validate_bluetooth_cs_channel_map(cs_mode, ...)	sl_rtl_util_validate_bluetooth_cs_channel_map(main_mode, sub_mode, ...): Input parameter `cs_mode` renamed to `main_mode` and new parameter `sub_mode` added.

Removed APIs#

None.

Deprecated APIs#

None.

Bug Fixes#

ID	Issue Description	GitHub / Salesforce Reference (if any)	Affected SW or HW Variants, Modes
1569167	Maximum distance limitation of 40 m for PBR estimation in algorithm mode SL_RTL_CS_ALGO_MODE_TRACKING_ACCURACY_OPTIMIZED has been removed.	None	SL_RTL_CS_ALGO_MODE_TRACKING_ACCURACY_OPTIMIZED
1524912	CS API will now return error if the unsupported combinations listed below are attempted: Main mode: PBR, sub mode: RTT, algorithm mode: SL_RTL_CS_ALGO_MODE_TRACKING_LATENCY_OPTIMIZED or SL_RTL_CS_ALGO_MODE_TRACKING_ACCURACY_OPTIMIZED, Channel map preset: MEDIUM.	None	PBR with RTT sub mode

Chip Enablement#

None.

Known Issues and Limitations#

ID	Issue or Limitation Description	GitHub / Salesforce Reference (if any)	Workaround (if any)	Affected Software Variants, Hardware, Modes, Host Interfaces
1442293	The velocity output in RTF algorithm mode is for experimental use only in this release. The value may have large outliers, and the distance measurement may stay fixed around the same value in certain cases e.g., when the device is in back pocket.	None	None	EFR32xG24
1449019	The RTF algorithm mode with medium channel map has weak accuracy in some NLOS cases.	None	None	EFR32xG24
1569167	The maximum range is limited to 70 meters in STATIC_HIGH_ACCURACY mode.	None	None	EFR32xG24

Impact of Release Changes#

Impact Statements and Migrations from 11.0.x to 11.1.0#

Change	Migration Guide	Affected Software Variants if applicable	Affected Modes	Affected OPNs / Boards / OPN Combinations	Affected Host Interfaces
Value change of SL_RTL_CS_MODE_NONE	Rebuild the application if this enum is used; otherwise no impact.	All	All	Hardware agnostic	N/A
Parameter change in sl_rtl_util_validate_bluetooth_cs_channel_map	Update calls to include the new sub_mode parameter. The cs_mode parameter has been renamed to main_mode.	All	All	Hardware agnostic	N/A

Using This Release#

Compatible Software | Installation and Use | Help and Feedback

Compatible Software#

Software	Compatible Version or Variant
Simplicity SDK	2026.6.0
GCC	14.2.1

Installation and Use#

For instructions on developing with the RTL library, see Developing Bluetooth Location Services Applications and the API reference included with the documentation installed through Simplicity Studio in the Bluetooth SDK.

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