According to the most recent report from J.D. Power & Associates, Alltel has the highest call quality in the Southeast and West regions of the U.S. and ties T-Mobile USA in the Southwest, while Verizon Wireless tops the call quality charts in the Northeast region and Mid-Atlantic region. U.S. Cellular tops call quality in the North Central region of the U.S. Article [1]
Links:
[1] http://www.fiercewireless.com/press-releases/j-d-power-and-associates-reports-alltel-t-mobile-u-s-cellular-and-verizon-wireless-ea