JD Power's latest call quality study has given Verizon the lead in call quality for its 13th consecutive period. The CDMA carrier had significantly better call quality in the US northeast, southeast, southwest and west. It only fell short of an unambiguous lead in the mid-Atlantic, where it was tied with AT&T, and in the north central area, where US Cellular had the fewest call problems.

Despite stereotypes, AT&T rarely had below-par call quality. It ranked last in the west, where its historically poor San Francisco Bay Area network dragged it down, and in the north central area, where Chicago has had trouble. Call quality in the southeast and southwest, including states like Florida and Texas, defined the average.

T-Mobile took last and was more often below average, though this might be owed to its younger 3G network. Sprint was mixed and sometimes above or below the average.