BlackBerry (NASDAQ: BBRY), Samsung and Apple (NASDAQ:AAPL) will soon battle for smartphone market share within the halls of the Pentagon. Indeed, BlackBerry and Samsung mobile devices are approved for use on Department of Defense (DoD) networks -- and Apple will likely gain approval soon. Those moves position the agency to engage with a variety of products and operating systems.

According to a Reuters report, the DoD rubber-stamped BlackBerry’s Z10 and Q10 smartphones and PlayBook tablets and Samsung’s Knox platform for use on its networks. Knox is a BYOD-centric, end-to-end secure solution that tightens security from the hardware through to the application layer--unveiled by the Korean manufacturer in early March.

For now, Samsung’s Galaxy S4 is its only mobile device sporting Knox-level security but the company said others, including tablets, will be appropriately equipped. BC Cho, Samsung’s enterprise unit chief, reportedly said it was “a little big embarrassing” to the company not to have its mobile devices used in government agencies especially considering its prominent position in the consumer market.

Next up on the Pentagon’s approval list is Apple iOS6-based mobile devices, expected at some point this month.

"This is a significant step towards establishing a multi-vendor environment that supports a variety of state-of-the-art devices and operating systems,” said Pentagon spokesperson Lieutenant Colonel Damien Pickart.

BlackBerry Alternatives

What does the Pentagon’s nod to Samsung (with Apple’s endorsement on the horizon) mean for DoD stalwart BlackBerry? For years, the DoD eschewed any mobile device maker other than BlackBerry over security concerns, but times have changed. In October, 2012, the DoD served noticed it planned to broaden its reach beyond BlackBerry to other suppliers, so none of this is at all surprising.

Nevertheless, BlackBerry has to be relieved that its new platform passed DoD security muster, considering the number of potential users in play. With some 3 million employees, the DoD has said that at some point it wants to be able to handle up to 8 million devices. Right now, of the 600,000 mobile devices used by the department, some 470,000 are BlackBerry smartphones and tablets.

Tablet Debate

Whether BlackBerry continues with tablets, however, is another matter--an open question at best. Thorsten Heins, BlackBerry chief executive, recently questioned the overall viability of the tablet market, noting that the company is rethinking if it wants to offer tablets at all. Its PlayBook entry has been a misfit from the start, prompting the vendor to take a huge inventory write-down in 2011 for unsold units.

“In five years I don’t think there’ll be a reason to have a tablet anymore,” Heins said recently in a Bloomberg report. “Maybe a big screen in your workspace, but not a tablet as such. Tablets themselves are not a good business model.”

Heins also reportedly said that he expects sales of BlackBerry’s keyboard-enabled Q10 device to reach into the “tens of millions.” The unit is slated to go on sale in the U.S. at the end of this month for $249. “This is going into the installed base of more than 70 million BlackBerry users so we have quite some expectations,” he said.