Is the Nokia 6111 compatible with Cingular (the new att)?

Answer 1

The Nokia 6111 is compatible with ATT/Cingular's 1900MHz GSM network.

This shows that Cingular has a 1900MHz network : http://www.gsmworld.com/roaming/gsminfo/net_usbe.shtml

This shows that the Nokia 611 has a 1900MHZ radio capability : http://europe.nokia.com/A4142073

This page gives some background on what device (phone) and network technologies are compatible with each other : http://en.wikipedia.org/wiki/GSM_frequency_ranges