licensed or unlicensed?
It all depends on the application. If the application is critical, or the network covers a large geographical area, or radio channel occupation rate is high, you will need to use a licensed frequency. This will ensure that the application will work well against possible interference (or if interference occurs, you can ask the government telecommunications service to locate and eliminate the interfering source). However, if you use an unlicensed frequency (433 MHz, 868 MHz or 929 MHz) you risk other surrounding radio systems interfering legally whilst your application is operating.
