I try connect the Airis 3G USB for Android tablet. It asks for password after the USB is recognized. Please let me know if this device have a default password.
The device doesn't have a default password. If you are prompted to input the password, then it means the password is for something else. However, I recommend using PPP Widget 2 on Android to connect through Internet using the USB modem.
Download through Play Store: https://play.google.com/store/apps/details?id=de.draisberghof.pppwidget2
Additional configuration is necessary based on the SIM card added to your device.