Wi-SUN SDK Version 2.6.0 (June 16, 2025) - Release Notes#

Simplicity SDK Version 2025.6.0

Wireless Smart Ubiquitous Network (Wi-SUN) is the leading IPv6 sub-GHz mesh technology for smart city and smart utility applications. Wi-SUN brings Smart Ubiquitous Networks to service providers, utilities, municipalities/local government, and other enterprises, by enabling interoperable, multi-service, and secure wireless mesh networks. Wi-SUN can be used for large-scale outdoor IoT wireless communication networks in a wide range of applications covering both line-powered and battery-powered nodes. Silicon Labs' Wi-SUN hardware is certified by the Wi-SUN Alliance, a global industry association devoted to seamless LPWAN connectivity. Wi-SUN builds upon open standard internet protocols (IP) and APIs, enabling developers to extend existing infrastructure platforms to add new capabilities. Built to scale with long-range capabilities, high-data throughput and IPv6 support, Wi-SUN simplifies wireless infrastructure for industrial applications and the evolution of smart cities.

Release Summary#

Key Features | API Changes | Bug Fixes | Chip Enablement

Key Features#

  • Added Wi-SUN+BLE dynamic multi-protocol (DMP) support.

  • Added concurrent detection support.

API Changes#

  • Added sl_wisun_set_preferred_pan() API that sets a FFN preferred PAN. A router will try to roam to its preferred PAN if it is available.

Bug Fixes#

  • Fixed an issue causing devices to be stuck in join state 3.

  • Fixed multiple MAC issues causing RCP instabilities.

Chip Enablement#

EFR32FG23 as RCP.

Key Features#

New Features | Enhancements | Removed Features | Deprecated Features

New Features#

  • Added concurrent detection support. EFR32FG25 is capable of receiving and processing FSK and OFDM without any prior negotiation, optimizing the mode switch procedure by making the mode switch PHR optional. Refer to AN1410 Getting Started with Concurrent Mode on EFR32FG25 using RAILtest for more information.

  • Added sl_wisun_config_concurrent_detection() API. It configures whether an alternate PHY can be used concurrently for transmissions instead of the standard mode switch.

  • Added Wi-SUN/BLE dynamic multiprotocol (DMP) support.

  • Updated BZ and SG channel plans according to Wi-SUN PHY TPS 2v03.

  • Ownership of chan_params_table is now transferred to the application. Each entry of chan_params_table defines a specific configuration containing PHY information such as the frequency, the channel numbers, and the modulation. It is recommended to adapt the content of the table to the end application use to optimize flash consumption. It is critical to ensure the content of the table is well aligned with the content of the configuration set in Simplicity Studio Radio Configurator.

  • Added sl_wisun_set_preferred_pan() API. It sets a preferred PAN ID that the device will always select during connection if available, or seek to roam to while connected to another PAN.

  • Added sl_wisun_config_neighbor_table() API. It configures the maximum number of RPL children, neighbors, and security neighbors, allowing fine-tuning of memory usage and network scalability.

  • Added sl_wisun_br_trigger_global_repair() border router API to manually trigger a global repair. It allows manual triggering of a global repair operation on the border router.

  • Added sl_wisun_br_get_routing_table_entry_count() and sl_wisun_br_get_routing_table() for the SoC Border Router. They can be used to retrieve the number of routing table entries and the routing table itself in order to render the network topology.

  • Added an event SL_WISUN_MSG_BR_ROUTING_TABLE_UPDATE_IND_ID that is triggered when the Border Router (BR) routing table is updated, with differentiation by update type. The structure returned by this event contains details about the routing table change, including the type of update and relevant routing entry information.

  • Introduced sl_wisun_lfn_params_t v3, with new eapol_unicast_interval_ms parameter.

  • Extended the network statistics (sl_wisun_statistics_network_t) with MPL statistics.

  • Extended the network statistics (sl_wisun_statistics_network_t) with the node's estimated hop count to the BR. Paired with sl_wisun_set_leaf(), it could be used to limit the depth of the network.

  • A SL_WISUN_MSG_NETWORK_UPDATE_IND event is now triggered upon a hop count estimation update. Added a new value SL_WISUN_NETWORK_UPDATE_FLAGS_HOP_COUNT to sl_wisun_msg_network_update_ind_body_t flag field.

  • Extended the MAC statistics (sl_wisun_statistics_mac_t) with the time spent in idle and TX states.

  • Extended the Heap statistics (sl_wisun_statistics_heap_t) with output highest used, currently used, free, and total heap space.

  • Extended the connection parameters (sl_wisun_connection_params_t) with fragmentation and EDFE configuration parameters.

  • Extended the LFN configuration parameters (sl_wisun_lfn_params_t) with EAPOL unicast wake-up interval.

  • Added multi-fragment EDFE support. EDFE is used automatically on all fragmented packets.

  • Introduced Wi-SUN NVM versioning.

  • ETSI Adaptive Power Control is now available for EU PHYs. It was previously limited to Indian configurations.

  • FFN and LFN now store frame counters for up to 15 different PANs. It was necessary to be able to navigate between two PANs either in the context of a switch to a preferred PAN or following multiple power outages.

Enhancements#

  • Rework the supplicant leading to significant RAM and Flash usage diminution.

  • Enhanced debug and trace capabilities for RCP and SoC. MAC traces are now enabled by default in the RCP.

  • ACK timeout is now measured to the start of the response frame, allowing faster RX channel return if no response is received.

  • EDFE FC-IE transmit flow control now matches estimated frame duration. It was previously set to the maximum value and was not used on the receiver's side.

  • Wi-SUN Header IEs (WH-IEs) from duplicate frames are now processed.

  • Delayed initial DIS to avoid overlap with PC sequence.

  • Added more meaningful status codes for SL_WISUN_MSG_SOCKET_DATA_SENT_IND_ID indication.

  • Temporary denial of routers unable to parent. Do not send unicast DIS to denied neighbors.

Removed Features#

None.

Deprecated Features#

None.

API Changes#

New APIs | Modified APIs | Removed APIs | Deprecated APIs

New APIs#

New API Signature

Deprecated API replaced by this (if any)

sl_wisun_set_preferred_pan()

None

sl_wisun_config_neighbor_table()

sl_wisun_set_neighbor_table_size()

sl_wisun_br_trigger_global_repair()

None

sl_wisun_config_concurrent_detection()

None

sl_wisun_br_get_routing_table_entry_count()

None

sl_wisun_br_get_routing_table()

None

Modified APIs#

Removed APIs#

None.

Deprecated APIs#

Deprecated API Name

Planned Removal Date

sl_wisun_set_neighbor_table_size()

Not before June 5, 2026

Bug Fixes#

ID Issue Description GitHub / Salesforce Reference (if any) Affected Software Variants, Hardware, Modes, Host Interfaces
1373901Fixed mode switch from router to LFN.FFN
1384392Fixed a PSA crypto key leak that prevented authentication after multiple attempts during the device's lifetime.FFN
1385981Fixed a critical failure when receiving a GKH in join state 1 by dropping security handshake frames from previous connections.FFN
1385791Fixed an issue that prevented LFNs from sending LPAS.LFN
1388948Fixed LFNs not unregistering from multicast groups when the corresponding socket was closed.LFN
1144019Fixed MPL messages being transmitted more times than the MPL "TimerExpirations" configuration allowed.BR, FFN
1392144Fixed DHCP preferred lifetime being invalid when the address lifetime was infinite.FFN
1393742Fixed SoC BR task priority starvation by the Wi-Fi backhaul task.BR
1366711Fixed unregistering when changing parent (sent NS(ARO) with no lifetime).FFN
1394368Fixed RPL Global Repair not transmitting DAO if the same preferred parent was selected.FFN
1390717Fixed memory corruption causing authentication failures on Secure Vault Mid devices.BR, FFN, LFN
1399233Fixed neighbor cache refresh procedure.BR, FFN
1389186Fixed LFN being blocked in reception state for the duration of a broadcast interval.LFN
1394656Fixed aborted frames not generating confirmation, which caused many RCP stalls.BR, FFN, LFN
1401857Fixed LFN PAN Advertisement transmissions sometimes being stuck until timeout.LFN
1230806Fixed EDFE retransmissions not performing retries with CCA backoff.BR, FFN
1412771Fixed an FHSS synchronization issue caused by incorrect UFSI values.BR, FFN, LFN
1412117Fixed a radio configuration file error with SG PHYs.BR, FFN, LFN
1412791Fixed an issue where border router address/prefix lifetime was advertised as 0 instead of infinite in DIO packets.BR
1411742Fixed an issue where nodes roamed back and forth with PAN Defect and Preferred PAN enabled. A device could not re-join its previous PAN before a given duration hardcoded in the stack.FFN
1414646Fixed an issue by analyzing inner IPv6 headers to refresh neighbor address registrations.BR, FFN
1419046Fixed an issue that caused devices to be stuck in join state 3 when they could not decrypt a PC from their previous PAN.FFN
1271915Fixed an issue that prevented DAO path sequence counter from resetting when going to join state 1 and 3.FFN
1426446Fixed a rescheduling issue with LFN frames that would make a node completely unable to operate.FFN, LFN
1425204Fixed invalid duplicated frame detection from LFN neighbors as an FFN.LFN
1425204Fixed invalid duplicated frame detection from FFN parent as an LFN.FFN
1438701Fixed an LFN issue when multiple frames advertised an updated LUS-IE.LFN
1440283Fixed an issue handling invalid 4WH message 3 and GKH message 1.FFN, LFN
1437500Fixed the return option value of getsockopt() for SO_SNDLOWAT option.BR, FFN, LFN
1436839Fixed send/sendto setting the wrong errno when sendq was full and socket was not in blocking mode.BR, FFN, LFN
1436839Fixed send/sendto not returning the correct number of sent bytes in the case of a partial packet send.BR, FFN, LFN
1435786Fixed setting errno values for socket API. It was missing for some of the socket APIs.BR, FFN, LFN
1442451Fixed synchronization to broadcast schedule after LFN parent selection.FFN, LFN
1429143Fixed an issue by deleting ND entries upon the reception of a NS with ARO containing a lifetime of 0.BR, FFN
1445797Fixed incorrect backoff slot duration with SUN OFDM.BR, FFN, LFN
1441981Fixed an issue where LFN failed in join state 3 when it failed to decrypt an FFN-specific packet.LFN
1424293Fixed an issue where PAN Defect IE was relayed twice by FFNs.FFN
1446315Fixed ETSI Adaptive Power Control with FAN TPS version 1.0.BR, FFN, LFN
1452100Fixed invalid default k trickle parameter.BR
1453003Fixed an issue that caused the connections to be significantly longer when an error occurred while trying to send a DAO. Routers were unable to send a second DAO until PAN timeout.FFN
1454000Fixed an issue where Preferred PAN and PAN Defect generated too much traffic.FFN
1387966Fixed an issue where RCP reset was triggered when MAC purged LFN frames upon LFN PAN Advertisement transmission. It was an abusive critical failure.RCP
1402855Fixed Source Addressing Mode of EDFE Response Frames in the RCP.RCP
1377305Fixed a wrong error message when reconnecting during an ongoing disconnection.CLI
1390370Fixed handling of SL_WISUN_MSG_REGULATION_TX_LEVEL_IND_ID.BR

Chip Enablement#

Chip Family OPNs / Boards / OPN Combinations Supported Software Variants (if applicable) Supported Modes Supported Host Interfaces
EFR32xG23
  • OPN: efr32fg23a010f512gm48, efr32fg23a020f512gm40, efr32zg23b010f512im48, efr32fg23b010f512im40, efr32fg23b021f512im40, efr32fg23a011f512gm40, efr32fg23b010f512gm48, efr32zg23a020f512gm48, efr32fg23b021f512im48, efr32zg23b020f512im48, efr32fg23b020f512im48, efr32fg23b020f512im40, efr32zg23b010f512im40, efr32zg23a010f512gm48, efr32fg23a010f512gm40, efr32zg23a020f512gm40, efr32fg23a021f512gm40, efr32fg23a020f512gm48, efr32zg23a010f512gm40, efr32zg23b021f512im40, efr32zg23b020f512im40, efr32zg23b011f512im40, efr32fg23b010f512im48
  • Boards: brd4204d, brd4210a, brd4263c, brd4264c, brd4265b, brd4269b
 N/ARCPUART

Application Example Changes#

New Examples | Modified Examples | Removed Examples | Deprecated Examples

New Examples#

Example Name Description Supported Software Variants (if applicable) Supported Modes Supported OPNs / Boards / OPN Combinations Supported Host Interfaces

Wi-SUN BLE DMP - SoC Empty

Application Readme

 The Wi-SUN Bluetooth DMP - SoC Empty example project serves as a starting point for developing Wi-SUN and BLE DMP applications. This example can be tested using the Simplicity Connect smartphone application, available on iOS and Android. N/A SoC
  • Parts: EFR32xG28
  • Boards: BRD2705A BRD4400A BRD4400B BRD4400C BRD4401A BRD4401B BRD4401C
 N/A

Wi-SUN BLE DMP - SoC SPP

Application Readme

 The Wi-SUN BLE DMP - SoC SPP example demonstrates how to use the Serial Port Profile (SPP) over Bluetooth Low Energy (BLE) to enable wireless serial communication between devices, providing a wireless alternative to traditional wired serial connections. This application reroutes the command line interface (CLI) over BLE, allowing users to interact with the device remotely. You can test this example using the Serial Bluetooth Terminal app for Android. N/A SoC
  • Parts: EFR32xG28
  • Boards: BRD2705A BRD4400A BRD4400B BRD4400C BRD4401A BRD4401B BRD4401C
 N/A

Modified Examples#

Example Name Changes Supported Software Variants if applicable Supported Modes Supported OPNs / Boards / OPN Combinations Supported Host Interfaces

All examples

 Migrated all the examples to the new System Setup component. N/A N/A
  • All supported parts
  • All supported boards
 N/A

All examples

 Refactored polling loops in the CoAP, TFTP Client, OTA DFU, and Ping components. Introduced a new sl_tftp_clnt_wait_op_finished API to wait for the operation finished event flag. N/A N/A
  • All supported parts
  • All supported boards
 N/A

All examples

 Enabled RTS/CTS flow control in the applications. N/A N/A
  • All supported parts
  • All supported boards
 N/A

All examples

 Introduced new CLI command configurating RTT Trace level and forwarding the content of RTT traces. N/A N/A
  • All supported parts
  • All supported boards
 N/A

Wi-SUN - SoC Network Measurement

 Added support for displaying estimated hop count to the Border Router in the measurement output. N/A N/A
  • Parts: EFR32FG25
  • Boards: BRD2705A BRD4270A BRD4270B BRD4271A BRD4272A BRD4276A
 N/A

Wi-SUN - SoC Socket application

 Updated socket_read CLI command for UDP. Removed the misleading read size argument. The whole received buffer should be read, this argument is unnecessary. N/A N/A
  • All supported parts
  • All supported boards
 N/A

OTA DFU component

 Increased SL_WISUN_OTA_DFU_TFTP_TIMEOUT_SEC to 8 seconds in OTA DFU config N/A N/A
  • All supported parts
  • All supported boards
 N/A

OTA DFU component

 Fixed TFTP Error code typos and added additional debug logs to the error handling in OTA DFU component. N/A N/A
  • All supported parts
  • All supported boards
 N/A

Removed Examples#

None.

Deprecated Examples#

None.

Known Issues and Limitations#

ID Issue or Limitation Description Workaround (if any) Affected Software Variants, Hardware, Modes, Host Interfaces
Wi-SUN Configuration is only capable of provisioning routers using the new Dynamic Data Provisioning methodology. The generation of border router certificates is not supported. Use the previous provisioning methodology. All supported parts and boards
1119464 Packets sent when FSK FEC is enabled can infringe ARIB regulation. Until this problem has been addressed correctly, the stack will refuse to start if both ARIB enforcement and FEC are enabled. All supported parts and boards
1067978 Packets sent using a PHY with a bandwidth larger than the base PHY’s bandwidth can infringe ARIB regulation. Limit the communications when using mode switch with ARIB enforcement enabled. EFR32FG25
1176014 FG25 asserts with a RAIL_ASSERT_FAILED_RTCC_SYNC_STALE_DATA error code when entering EM2. Do not allow the power manager to go to EM2 by adding a requirement on EM1 in the application. EFR32FG25
1373879 The RCP is sometimes unable to send packets using mode switch. None EFR32FG25
Throughput is reduced compared to previous releases due to the fix for 1445797. The previous CSMA slot duration was too short, which artificially increased throughput. The impact is more noticeable with high-throughput modulations. Further investigation will be run to better understand and improve the current performances. None EFR32FG25
Wi-SUN RCP operation on EFR32FG23 requires hardware flow control to be enabled. Without hardware flow control, CPC requires an additional buffer, which exceeds the available RAM on this device. None EFR32FG23

Impact of Release Changes#

Impact Statements | Migration Guide

Impact Statements#

None.

Migration Guide#

Previous versions of "Wi-SUN - LFN CLI" were using SL_POWER_MANAGER_EVENT_TRANSITION_ENTERING_EM3 that was removed in that version 2025.6 of the SiSDK. Applications generated with an older release of the SiSDK will not compile against version 2025.6. All references to SL_POWER_MANAGER_EVENT_TRANSITION_ENTERING_EM3 can be safely deleted.

Using This Release#

What's in the Release?#

This release contains the following:

  • Wi-SUN stack library

  • Wi-SUN sample applications

  • Wi-SUN border router and RCP pre-compiled demos

  • Documentation

If you are a first-time user, see the Wi-SUN Getting Started Guide.

Compatible Software#

Software Compatible Version or Variant
Wi-SUN Linux Border Router (wsbrd) v2 and more recent.
Wi-SUN Linux Router (wsrd) v2.2 and more recent.

Installation and Use#

The Wi-SUN SDK is distributed as part of the Simplicity SDK, Silicon Labs' unified software development kit suite. To get started quickly, install Simplicity Studio 5, which provides a complete development environment, including project and resource management, software configuration tools, a full IDE with GNU toolchain, and analysis utilities. Step-by-step installation instructions are available in the Simplicity Studio 5 User’s Guide.

Alternatively, you can manually install the Simplicity SDK by downloading or cloning the latest release from GitHub.

By default, Simplicity Studio installs the Simplicity SDK to:

  • Windows: C:\Users\<NAME>\SimplicityStudio\SDKs\simplicity_sdk

  • macOS: /Users/<NAME>/SimplicityStudio/SDKs/simplicity_sdk

Documentation for each SDK version is included with the SDK installation.

For information about Secure Vault Integration, see Secure Vault.

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Help and Feedback#

SDK Release and Maintenance Policy#

See our SDK Release and Maintenance Policy.