said by Morac:AT&T works great at my home and my office, yet if I go to my parents house less than an hour away I barely get a signal.
Also AT&T's signals seem to have a hard time penetrating buildings with a lot of metal in them. There's a metal building that I go to that's a dead zone for AT&T, but Verizon works fine there.
1 of 2 things...either the VZW tower is very close to that metal building, making the building's attenuation less than the signal strength. Other possibility is VZW is using the 850 MHz CDMA band while ATT is using 1900 MHz GSM or 2100 MHz(which they sometimes use for UMTS, which you didn't happen to mention whether it was a UMTS area). That would greatly depend on area which bands are used by which carrier. In another area, VZW may be using the 1850 MHz CDMA band while AT&T is using the 850 MHz GSM band. Sometimes, it's all on the terrain and where there is available spectrum for another provider. I mention this because in some areas, you'll probably observe the opposite, as to building penetration. AT&T uses alot of 1900MHz here in the small city of Pittsfield, with some 850 in outlying areas of the county. They seem to have enough towers here though to get away with 1900.