Next is the ratings for Wireless Call Quality, which measures the call quality among the major U.S. wireless service providers in six regions and is based on factors that impact overall carrier performance. For this, JD Power surveyed 24,300 wireless phone subscribers between July and December 2009 to find out their experience with dropped calls, static/interference, failed connection on the first try, voice distortion, echoes, no immediate voice mail notification, and no immediate text message notification. Verizon Wireless was ranked 1st place in the Northeast Region, Mid-Atlantic Region, Southeast Region, Southwest Region, and Western Region. The only area where Verizon came in 2nd place (and tied with Sprint and T-Mobile) was the North-Central Region, which gave 1st place to U.S. Cellular.
source: Verizon Wireless and JD Power