A study measuring the performance of the iPhone 4S on the three major U.S. 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 network.
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 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.
Metrico measured five performance factors shortly after the iPhone 4S was launched on all three carriers in October: whether calls could be connected and held; voice quality; data performance; Web browsing by page load speeds and video performance.
In all, Metrico performed 21,000 Web page downloads nationwide with the iPhone 4S and iPhone 4 over the networks of the nation's largest three carriers. Metrico also ran more than 8,000 data download and upload tests and generated about 6,000 voice calls with recorded human voices. The tests were performed in a certified lab as well as several locations in five unnamed cities that Metrico called "representative of [network] conditions nationwide."
Metrico did not pronounce any carrier a winner or loser in the study, noting that each had strengths. In an analysis of a summary of the findings, however, AT&T came out on top in more areas than the others, with Verizon second and Sprint third.
AT&T was widely criticized for network performance problems -- often for failed voice calls -- nearly four years ago when the iPhone first launched. Verizon's results were slightly better than AT&T and Sprint on the iPhone 4S's ability to connect and hold a call in Metrico's study. However, AT&T's iPhone 4S outperformed the Verizon and Sprint models in data downloads, uploads and in Web browsing.
AT&T was twice as fast as Verizon in Web browsing with the iPhone 4S, recording average page load times of 1.29 seconds, compared with Verizon's 2.60 seconds. Sprint's version of the phone took an average of 6.44 seconds for Web browsing page loads, according to Amit Malhotra, vice president of marketing at Metrico, in an interview.
Sprint, the nation's third-largest carrier, began selling the iPhone 4S and iPhone 4 for first time over its CDMA 3G network in October. It has recently begun national TV ads promoting Sprint's unlimited data plans for the iPhone, a distinction over the data tier pricing plans of AT&T and Verizon.
In terms of specific data download speeds, AT&T had an average speed of 3,210Kbps, compared to 1,071Kbps for Verizon and 581Kbps for Sprint, one-fifth the speed of AT&T. The maximum data download speed on AT&T was 6,047Kbps over its 3G GSM network. Metrico didn't supply actual data upload times to reporters.
Overall, Metrico rated all three carriers as "excellent" in the reliability of full delivery of data to the iPhone 4S.
AT&T's version of the iPhone 4S had superior data download speeds compared to Verizon Wireless and Sprint, according to tests by Metrico Wireless.
Other Metrico findings: