Network Settings - Zte R570 Quick Start Manual

Asked to enter the SIM card PIN code. After entering the correct before
setting. If the SIM card is set to ON, each time you boot, you need to
enter the PIN code, when entered incorrectly three times, it is required
to enter your PUK (Personal Unblocking Key). PUK code is used to unlock
and change the locked PIN code. If the PUK code is not provided or is
lost, please contact your network operator.
Mobile Security Settings:
Use the phone lock operation; enter the password when opening or
closing operation of the phone lock when the phone is turned off, you
will be asked to enter the phone password at boot time. Phone
password is 4 to 8 digits. The default password is "1122".
Change the password.
Privacy protection: After setting the privacy protection into different
menus are required to enter a password

Network settings:

Network -> mode selection: 2G only.
Connectivity
1. Activate or deactivate the Bluetooth.
[Power] Activate the Bluetooth function.
[Visibility] Activate /Deactivate this function.