[update]
The Samsung SM-B780A is available now from AT & T as Samsung Rugby 4. It is a basic feature handset.
Visit Samsung offcial Support page for Samsung Guby 4 here to find out the handset spes and features.
The still unannounced Samsung SM-B780A has just passed through the FCC with support for AT&T 3G bands.
According to FCC filling, the Samsung SM-B780A’s FCC ID is “A3LSMB780A″. It supports the 850/1900 MHz GSM/WCDMA bands which means that it will work on AT&T’s 3G/HSPA network. Moreover, the letter “A” at the end of the model number suggests that AT&T will carry the device.
The FCC reveals that the SM-G870A is 108mm tall, and 54mm wide. The SM-B780 is identified as “portable handset” by FCC document.
That’s all we know about the Samsung SM-B780A handset so far.