Amazon Sidewalk Physical Layer and Configuration#

Switch Between BLE, FSK, and CSS#

When Multi-link or Auto connect is enabled, the system automatically switches between links based on certain criteria, such as a timeout during time synchronization attempts. For more details on these features, refer to Multi-link.

If you prefer to manually switch between radio links, you can stop the Sidewalk stack using sid_stop and restart it with sid_start, specifying a different sid_link_type link_mask parameter.

Additionally, it is possible to run another protocol alongside Amazon Sidewalk. The Amazon Sidewalk - SoC Dynamic Multiprotocol Light application demonstrates Client BLE working alongside Sidewalk BLE and Client BLE working alongside Sidewalk FSK. You can also implement double advertising in Amazon Sidewalk or perform an OTA using the standard BLE stack. For implementation details, refer to the Multiprotocol documentation.

Change Radio Configuration#

In the Amazon Sidewalk Empty sample application, the radio is pre-configured with selected parameters. You can modify these parameters by editing the parameter of the sid_platform_init function call in app_init.c.

sid_error_t sid_platform_init ( const void * platform_init_parameters );

The BLE configuration is managed in the component/sidewalk_radio_config/ble/app_ble_config.c file of the Sidewalk extension, with the main configuration structure being sid_ble_config_t ble_cfg. The sub-GHz configuration is divided between different sub-GHz solutions: one for the native radio for Silicon Labs parts that support FSK modulation, and one for the external radio when using an external Semtech radio transceiver. The sub-GHz parameters can be found in the sidewalk_<extension_version>/component/sidewalk_radio_config/subghz/ folder, specifically in app_subghz_config.c under rail/ folder for the native radio, with radio_efr32xgxx_device_config_t radio_efr32xgxx_cfg as the base structure, and under semtech/ folder for the Semtech radio, with sid_sub_ghz_links_config sub_ghz_link_config as the base structure.

Change Amazon Sidewalk Power Profile#

With sub-GHz radio, besides adjusting the radio parameters, you can also select a configuration profile, known as a power profile. This profile alters the protocol behavior by modifying aspects such as the number of listening windows or their periodicity.

For FSK, refer to the documentation on FSK Configuration.

For CSS, refer to the documentation on CSS Configuration.

Modifying the power profile or parameters of the radio link affects the performance of the Amazon Sidewalk protocol. For more details, refer to our study on Amazon Sidewalk performance.