Credit: Root Wireless

With tens of thousands of techies all attempting to use their smartphones at once, the giant Consumer Electronics Show in Las Vegas gave Bellevue-based Root Wireless an opportunity to test what happens to wireless data networks when they're hit with significantly higher-than-normal levels of congestion.

And if any other attendees had trouble downloading data over AT&T's network during the show, the results show we weren't alone. Blame the popularity of iPhones if you will, but AT&T's download speeds lagged under the weight of heavy usage during peak times at CES, according to the Root Wireless analysis.

The company used as a baseline the network performance on Tuesday, Jan. 5, before the show really got rolling. Here's its summary of what happened as the population at the convention swelled.

Over the four days tested, AT&T’s rank fell from first to last.

The first two days, Sprint’s data service provided faster service than recorded in greater Las Vegas in December. Then its download speeds slowed each of the following two days. Nonetheless, its service was among the fastest recorded Wednesday - Friday.

T-Mobile’s service never recorded the fastest download speeds, but it provided consistent performance day-to-day.

With the exception of Wednesday, Verizon Wireless outperformed its results recorded in December, and Verizon provided the fastest downloads on Thursday and Friday, presumably the show’s most congested days.

CES is an extreme example, but Root Wireless is aiming to give consumers a sense for what type of network performance they can expect in the neighborhoods where they use their phones, helping them decide which wireless network to choose. It gathers data using its Root Mobile crowdsourcing app.

See this CNet page for the company's coverage maps.