Bluetooth Location Services Version 11.0.0 - Release Notes (Jan 22, 2026)#
Simplicity SDK Version 2025.12.0
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#
Support for multiple sub-events per initiator and reflector role in a CS procedure.
Support for non-zero maximum procedure count in REAL_TIME_FAST algorithm mode.
API Changes#
Value change of enum item SL_RTL_CS_MODE_NONE.
RSSI data type change in struct sl_rtl_cs_mode_calib_data.
Bug Fixes#
Selected bug fixes for accuracy estimation.
Chip Enablement#
None.
Key Features#
New Features | Enhancements | Removed Features | Deprecated Features
New Features#
RTL now supports multiple sub-events per initiator and reflector role in a CS procedure. Previously only 1 sub-event was supported.
RTL now supports non-zero maximum procedure count in REAL_TIME_FAST algorithm mode. Previously only value 0 was supported.
Enhancements#
RTT accuracy improvements.
Removed Features#
None.
Deprecated Features#
All estimation for the Channel Map Preset LOW is deprecated in this release. The support will be removed from the next major release.
The RTL library for x86_64 macOS is deprecated in this release. The support will be removed from the next major release.
API Changes#
New APIs | Modified APIs | Removed APIs | Deprecated APIs
New APIs#
None.
Modified APIs#
Old API | Modified |
|---|---|
enum sl_rtl_cs_mode { SL_RTL_CS_MODE_NONE = 3 } | enum sl_rtl_cs_mode { SL_RTL_CS_MODE_NONE = 0xff } |
struct sl_rtl_cs_mode_calib_data(uint8_t packet_quality, uint8_t packet_rssi, ...) | struct sl_rtl_cs_mode_calib_data(uint8_t packet_quality, int8_t packet_rssi, ...) |
Removed APIs#
None.
Deprecated APIs#
None.
Bug Fixes#
| ID | Issue Description | GitHub / Salesforce Reference (if any) | Affected Software Variants, Hardware, Modes, Host Interfaces |
|---|---|---|---|
| 1501684 | Fixed an issue in the STATIC_HIGH_ACCURACY mode that may affect the accuracy in some circumstances. | None | All; generic software issue |
| 1509641 | The RTF estimator will no longer return a raw distance of 40m if no valid distance is found. | None | All; generic software issue |
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 40 meters in RTB mode. | None | None | EFR32xG24 |
Impact of Release Changes#
Impact Statements and Migrations from 10.x to 11.0.0#
| 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 |
| Data type change in struct sl_rtl_cs_mode_calib_data | Pass in a signed-integer as RSSI value instead of unsigned-integer. | 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 | 2025.12.0 |
| GCC (The GNU Compiler Collection) | 12.2.1 (provided with Simplicity Studio) |
Installation and Use#
For instructions on developing with the RTL library, see AN1296: Application Development with Silicon Labs’ RTL Library and the API reference included with the documentation installed through Simplicity Studio in the Bluetooth SDK.
Development Kit customers are eligible for training and technical support. Use the Silicon Labs Bluetooth LE web page to obtain information about all Silicon Labs Bluetooth products and services, and to sign up for product support.
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SDK Release and Maintenance Policy#
See our SDK Release and Maintenance Policy.