T-Mobile plans to upgrade its 2G EDGE footprint to 4G LTE by mid-2015

You should be able to bid a final goodbye to that dreaded “E” icon on your T-Mobile(s tmus) handset within the next 15 months.

Celebrating the one-year anniversary of it’s LTE network launch on Thursday, T-Mobile announced network upgrade plans to transition its 2G EDGE service to 4G LTE. The company says it complete half of the network upgrade this year with substantial completion by the middle of 2015.

T-Mobile US CEO John Legere at CES

T-Mobile US CEO John Legere at CES

Essentially, this effort will bring T-Mobile’s entire network footprint up to 4G LTE speeds, even outside of the metro areas where it has focused on network upgrades. Helping the company’s plan is the 700 MHz A-block spectrum it purchased earlier this year from Verizon(s vz). My colleague Kevin Fitchard explained why when that $2.635 billion deal went through saying, “[T]he big knock on T-Mobile has always been that its impressive 3G and 4G speeds disappear once you leave the city limits. These low-frequency airwaves will let T-Mobile build wide-sweeping networks to fill in those gaps.”

The net result of the upgrade means that once a T-Mobile customer leaves a metro area, they won’t leave their LTE signal behind. And that’s key because dropping from 4G to 2G is like driving a race-ready Corvette in bumper-to-bumper traffic: It’s painful. Once the upgrade is completed, any service gaps in LTE coverage would be picked up by T-Mobile’s HSPA+ technology, often providing 21 or 42 Mbps service. That’s a bit more tolerable than dropping from LTE to EDGE service.

Mosaik MetroPCS T-Mobile network overlap

T-Mobile’s 2G service won’t disappear entirely. The carrier will keep EDGE service online to support low-tech phones and M2M connections. But this is definitely a big step forward in its plan to gradually phase out 2G capacity and rely primarily on LTE and HSPA+. The expansion will increase its LTE footprint by 40 million people, but they’re a significant 40 million. These are the people T-Mobile has traditionally ignored because of its focus on the urban metro markets.

While T-Mobile doesn’t have the broadest coverage today by comparison to its rivals, the operator has impressed with its speed of network upgrades. Consider that in just one year, it launched an LTE network that it says reaches 210 million Americans, and in less than another 15 months it will have LTE available throughout its entire coverage area.