Under CEO John Legere, T-Mobile (TMUS 0.92%) has cast itself as the "Un-carrier"  -- a company that breaks the long-held industry rules and does things differently.

As part of this initiative, Legere sought to make the business as transparent as possible for customers. The brand has dropped overage charges, eliminated device subsidies, done away with contracts, and generally shown customers exactly what they are paying for. T-Mobile has sought to bring honesty to an industry that has made its money by obscuring prices, luring customers in with too-good-to-be-true deals, and being not quite forthcoming with subscribers.

Now, T-Mobile has launched a new crowdsourced coverage map that shows exactly how well its network is performing. It is searchable by address, and the company shares the info even when it is not flattering.

What T-Mobile is doing
T-Mobile explained the new offering in a blog post from Chief Technology Officer Neville Ray, who called it the "Next-Gen Network Map." He explained that it reflects near real-time customer experiences on the company network based on "more than 200 million actual customer usage data points every day." The map also incorporates third-party customer usage data from other sources, including INRIX.

"For years, every carrier has produced their network map in the same way, based on 'predictive coverage estimations,'" Ray wrote. "The problem is that these maps are exactly that -- best estimates. But for some time now, there have been far more advanced methods and technologies available to produce far more accurate coverage maps -- based on the actual experience of real customers, like you and your family."

The Next-Gen Network Map shows areas where using T-Mobile services might be a good choice, like this coverage map that includes my home in Newington, Conn.

Source: Screenshot

It also shows areas of poor network coverage, such as the area around my family home in Jaffrey, N.H.

Source: Screenshot

As you can see, T-Mobile has the area around my house covered but offers no service at the New Hampshire house. That is unfortunate (and it is the sole reason I have not switched), but it is better that I know this before making a trip north with a phone that would not work.

T-Mobile has essentially provided a tool that tells me not to be a customer right now. That is not good for the company in the near term, but it greatly increases my willingness to switch should it improve its network in New Hampshire.

How does it work?
No more surveys or third-party testing, the new T-Mobile map relies on data provided by its actual customers. That delivers an honest appraisal of how the system is working at any given time, which allows people to make an informed decision.

Ray explained what the map shows in his post:

Customer-verified coverage based on actual customer usage, resulting in a vastly more transparent and accurate map, showing, for example, exactly where you can expect 4G LTE, 4G, 3G or other levels of coverage.

A Verified Coverage icon indicating where the majority of data is provided by T-Mobile customers reporting their actual network experience, providing an added layer of confidence.

Data that's updated twice monthly -- compared to data presented on the carriers' maps, which is already dated by the time it's printed and published and may be months or even years old.

Speed test data from trusted third party apps showing average download speeds from customer speed tests over the last 90 days.

Basically, T-Mobile is giving customers real data rather than forcing them to rely on claims made in commercials. That could lead to an increase in customers joining and increased satisfaction once they come on board.

Will this work?
T-Mobile ranked at the bottom of the RootMetrics 2nd Half 2014 U.S. Mobile Network Performance Review, but it has been gaining ground on leaders AT&T and Verizon. That survey showed that not only has the Un-carrier closed the gap, but in some areas, it has a very strong network.

Offering the Next-Gen Network Map allows customers to see if those improvements will impact them. For some, especially people living in more heavily populated areas, T-Mobile's weaknesses are not relevant. Being able to see how strong the coverage is exactly where they use the network most should remove any fears about signing up.

This may not be a game changer for T-Mobile, but it is a smart move that advances the Un-carrier agenda and showcases the company's willingness to be transparent with customers even when that transparency may not always benefit T-Mobile.