How to lock android sim network? I want to manually lock the android sim card network is that possible and how to do it?
From your homescreen ….


Tap the menu button/key
Select "Settings"
In the network settings, tap "more…"
Then tap "Mobile networks"
On the next screen, select "Network Operators"
Instead of "Select automatically", select your network operator manually here



Network selection screen (click for larger variant)

Note that the network must be available in order for you to select it. You cannot e.g. select an US network operator while you're in China :)