BARCELONA -- Mobile World Congress -- AT&T has added another 13 countries to the list of global LTE networks it will roam on, retaining the title as the only US operator to offer international LTE data roaming.

The carrier kicked off Mobile World Congress with the news that its customers can now roam in 15 countries with more on the way. AT&T Inc. (NYSE: T) added Spain, France, Japan, South Korea, Australia, Hong Kong, Switzerland, Malaysia, Russia, Singapore, Guam, Hong Kong, and Antigua & Barbuda to the lineup which has included Canada and the UK since December. (See AT&T Inks First LTE Roaming Deal in Canada and NTT Docomo Offers 4G Roaming to AT&T.)

The carrier has also updated its international travel app to make it easier to access roaming package information, track usage, and answer questions about roaming abroad. The app was born from its Foundry Innovation Center in Israel. (See AT&T Opens New Innovation Labs.)

Why this matters
AT&T has the distinction of being the only US operator to offer LTE roaming, at least for now. Interestingly, Verizon Wireless was the one that made the biggest deal about the ability to connect with other operators around the globe, noting back in 2011 that it was nearing deals in China and the UK. That hasn't come to pass as yet. So far neither AT&T or Verizon have a roaming deal between their respective LTE networks in the US either. (See Verizon Eyes LTE Roaming in Europe, Canada, Verizon LTE Plan Not a Rural Slam-Dunk, and LTE: Don’t Expect to Roam Soon.)

Global 4G data roaming is increasingly important as LTE becomes the global standard in wireless, despite disparate spectrum bands, but expensive data pricing will still hold back a lot of users from taking advantage of plans. Most of the US operators have 3G roaming deals in place, but LTE deals are still be worked out in much of the world.

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— Sarah Reedy, Senior Editor, Light Reading