Find the 3G band for Nexus One

Given a nexus one (rather any An开发者_StackOverflowdroid phone), is it a way to find out which 3g band it supports (t-mobile or att), without inserting any SIM cards ? currently I'm just interested in nexus one, but generic info can be useful too.

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Yes there is. Take off the back cover off the Nexus One, remove the battery and read the FCC ID number at the top of the black area.

The FCC # for the AT&T version is NM8PB99110

The FCC # for the T-Mobile version is NM8PB99100