how do i manualy add networks to my lg optimus g?

[Android Question]

i have an lg optimus g... bought it from amazon and used it in the u.s. for a month, but when i got the at&t chip the data wasnt working, i went to at&t an they fixed it, on the phone settings somehow they added manualy a conection to the at&t data network, or something similar...

now i came back to my country, where the costumer service is reeealy bad, and the same is happening to me, its like the phone recognizes the sim card but stays with a gsm network, even when it has the data enabled, on network prefferences i got all of them not only gsm, got the wifi turned off, i cant seem to find the right setting to fix this.

 

[Mr. Lucky]

Buried in Settings is the network APN configuration. That's what AT&T set. The info you're seeking is freely available by searching online for carrier name and APN (e.g., "Orange APN").