Verizon Wireless (VZ, VOD) received top marks in J.D. Power's annual study of U.S. mobile network quality. Big Red was said to have the best network in 5 of the 6 regions covered in the study, which measures issues such as dropped call rates and Web connection errors. U.S. Cellular (USM) was named the best carrier in the "North Central" region, while AT&T (T) was declared the worst carrier in 4 of 6 regions. Verizon is hoping its network will allow it to maintain premium pricing.