Who operates Boston's best mobile network? New data from SwayMarkets ranks AT&T, Sprint and Verizon

By Scott Kirsner, Globe Columnist

Nick Chory from the Cambridge start-up SwayMarkets sends along an interesting infographic about the best-performing 3G wireless carriers in Boston, based on factors like data speed and signal strength. And SwayMarkets monitors the experience of actual subscribers, as opposed to relying on marketing claims made by the carriers.

The top-line results? Verizon subscribers get the best signal strength, fastest data transfers, and least latency. (See the infographic below.)

SwayMarkets was founded by a trio of EnerNOC alumni, and their plan is to collect data about mobile carriers' performance in big cities that could then be sold to companies that, for instance, have a large sales force relying on 3G tablets and want to know what carrier to use in different cities to ensure solid coverage. The data could be valuable for consumers, too, Chory says: "If your subscription is up for renewal, wouldn't it be great to know what carrier is the best for you if you work downtown and live in Cambridge?"

SwayMarkets has already produced two free apps for iPhone users: DataMonitor, which keeps tabs on your monthly data usage so you don't incur extra fees, and NetSnaps, which tells you how the WiFi or wireless network is performing where you are.

"We've been collecting anonymous data with both of the apps and analyzing it," says Chory. "We're presenting it for Boston first, but we can do it in any geography." Though the data is collected only from iPhone users at present, the company asserts that it's valid no matter what sort of device you're using on the Sprint, AT&T or Verizon networks. (And SwayMarkets plans to soon start collecting data through other devices.)

Here's SwayMarket's infographic on the best cellular service in Boston: