PC World commissioned Novarum to conduct a one day (but intensive) test of AT&T, Sprint and Verizon's 3G wireless networks in 13 major markets...

A Day in the Life of 3G

The results are quite interesting, sometimes surprising and reinforces the gut feeling that many users of AT&T 3G networks have long suspected:

Reliability was an issue in our experience of the AT&T system: Our testers were able to make a connection at a reasonable, uninterrupted speed in only 68 percent of their tests.

According to the article, however, AT&T stands by its claim that it has the fastest 3G network in the U.S. However, given the 68% reliability, it may be that this is only for burst rate measures.

I was surprised to see that while AT&T's 3G had a slower average download speed than Verizon, it was about the same as Sprint's 3G which has a word-of-mounth reputation for being fast.

Another semi-surprise (though perhaps not too much for those who have long wondered about how informative signal bars are) is that the study found that the signal strength bars are not predictive of service quality. However, on a personal note, I can tell you from personal experience that when my iPhone says I have "No Service", I cannot make or receive a phone call over the AT&T GSM voice network.