A simple fix could address multiple complaints about Google's Nexus One smartphone and its patchy 3G performance. According to Kevin Tofel at jkOnTheRun, setting his smartphone to automatically choose its preferred carrier caused it to instantly hop on board T-Mobile's 3G network.
"In “Settings,” I went to “Wireless & networks.” Look for the “Mobile Networks” option at the bottom of this listing. The next screen has a “Network Operators” section — tap it. Your Nexus One will search for compatible GSM networks in the area. Once it’s complete, you’ll see the choices, which will consist of T-Mobile and/or AT&T. You’ll also see a choice to Select Automatically — tap it and your phone should say “Registered on network.” That’s it. That’s all I did and I immediately saw the phone jump from EDGE to T-Mobile’s fast 3G network."
Previously Kevin had been stuck with EDGE connectivity, despite other handsets (with similar support for the T-Mobile 3G bands as the Nexus One has) being able to pull in high-speed 3G downloads and uploads while in the exact same location. Even after rebooting, the Nexus One now automatically locks onto the T-Mobile 3G network.
It's unclear what the explanation for this fix is, though it seems that somewhere in the setup or firmware of the Nexus One the handset has been instructed to prioritize EDGE connectivity over 3G. It's possible that this is to ensure broader connectivity overall - though at a lower speed - but so far Google and T-Mobile are yet to comment. Nexus One owners, let us know if this works for you!