All of Greeley Ave in north Portland is a deadzone for AT&T TDMA.

Stops around sunset high near their tower.

AT&T's GSM network is worthless. In the west hills there is zero reception. It only starts to work somewhat when you get into downtown and off the west hills. Do not use this service! I switched to AT&T's TDMA and have been very pleased with the service. Also, TDMA phones have analog roaming, which means you can make 911 calls, etc. in the country.

fair signal strength, but no network service. Verified with other AT&T users.

I lose calls when I hit around 20th and Belmont and have absolutely nothing (can't make or receive calls or SMS-nothing) until I hit around 35th. Then I get poor service, not no service.

ATT GSM network service is awful (please read it SUCKS!) in the Southern Oregon Rogue Valley. My sony e610 phone doesn't even work half the time due to poor reception. Besides that ATT charges me extra (usually $30/month) for incoming "call forwarding" calls even when I don't answer them, due to the phone automatically reverts to another network signal because ATT is so weak. ATT has been little or no help solving the problems...wish I could get out of my contract.