Three times as many as Verizon, according to a consumer survey released Tuesday
AT&T (t) announced in January that it was spending $2 billion this year to improve its much maligned cellular network.
In a poll that asked 4,040 smartphone users in March how many dropped calls they had experienced in the past three months, AT&T -- the exclusive U.S. carrier of Apple's (aapl) iPhone and iPad mobile devices -- came in dead last among the country's four largest carriers.
Verizon (vz) customers reported losing only 1.5% of their calls over the past three months, the lowest in the smartphone industry and the lowest percentage for a carrier ever recorded by ChangeWave.
AT&T customers, by contrast, reported 4.5% of calls dropped in the last three months. That's one out of every 22 calls -- three times as many as Verizon's and the worst percentage ChangeWave has ever seen.
This is not good news for AT&T or for Apple, which has cited AT&T's plans for improving its network as the reason it is sticking with the carrier -- at least for now.
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Below: A chart tracking the results of similar surveys dating back to Sept. 2008. It shows a growing number of dropped calls for AT&T and a steadily falling number for Verizon.
The number of calls that get dropped by one's carrier correlates closely with overall satisfaction, according to ChangeWave, as evidenced by the chart below:
The survey was conducted between March 9 and March 23.
For other recent ChangeWave reports, see:
[Follow Philip Elmer-DeWitt on Twitter @philiped]