All of the embedded modules follow the same plan: a host microcontroller at the designer’s end hosting the application and then talking via UART to the module itself and then either 2.4 GHz or in the case of the sub-Gigahertz and other devices, 915 or in Bluetooth 2.4 GHz also. It is a serial-to-RF application, so in most cases the entire application interface in the stack are all on the module.