If the Bluetooth of the smart phone is turned on, the Ultra Stream App can discover the encoders via Ethernet or Wi-Fi. When your smart phone and your Ultra Stream encoders are connected within the same subnet, the App will search for available devices automatically and pair your phone with the Ultra Stream encoder you choose. Even if there is no Wi-Fi network onsite or the wireless environment is complicated, you can turn on the AP mode of the encoder via your Ultra Stream App to connect the encoder to your phone. You can check here
for how to enable the AP mode.