AT&T fastest US network for iPhone 4S

wireless carriers found AT&T to be superior in Web browsing and data downloads and uploads when compared to Apple's latest smartphone on either the Verizon Wireless or Sprint networks, Computerworld reports.

iPhone newcomer, Sprint was found to be superior with its iPhone 4S for network voice quality on the uplink (when the user is speaking), but Sprint was also about five times slower in Web browsing and data downloads than AT&T, according to the study, released on Friday by Metrico Wireless, a mobile performance measurement company. Verizon finished in the middle on those data tests, but trailed the other two carriers in voice quality.

"The AT&T iPhone 4S outperforms its Verizon and Sprint counterparts in data download and upload speeds," PCMag quotes Metrico as saying.

"Moreover, the AT&T iPhone 4S outperforms the iPhone 4 in download speeds by a considerable margin."

According to Mobiledia, Metrico's study found the 4S's call success rates were slightly better for Verizon than the others, while Sprint's 4S has better live network voice quality when a user is speaking. But AT&T's version took the lead on downlink speeds, which the report concluded makes the two carriers similar where voice quality is concerned, and the jury may still be out over whether the study will affect customers' opinions.