Gartner says that global sales of ‘smart devices’ – smartphones and tablets – will pass 1 billion in 2013.

The research firm says that 821 million such devices will be purchased this year, accounting for 70 percent of total devices sold, and having a profound impact on the enterprise sector.

“For most businesses smartphones and tablets will not entirely replace PCs, but the ubiquity of smartphones and the increasing popularity of tablets are changing the way businesses look at their device strategies and the way consumers embrace devices,” said Gartner’s Carolina Milanesi.

She added that, by 2016, two-thirds of the mobile workforce will own a smartphone, and 40 percent of the workforce will be classed as “mobile.”

Tablets will be the “key accelerator to mobility.” Gartner estimates that in 2012 purchases of tablets by businesses will reach 13 million units and will more than triple by 2016, reaching 53 million.

On the smartphone side, Gartner estimates that 56 percent of smartphones purchased by businesses in North America and Europe will be Android devices in 2016, up from 34 percent in 2012 and virtually no penetration in 2010.

The increasing penetration of Android in the enterprise will continue to pose challenges for the IT department and the CIO “to ensure that security and manageability remain a priority,” says Gartner.

But it nevertheless expects Android and iOS devices to continue to increase their presence in the enterprise –  in most cases at the expense of RIM.

“As businesses are looking for a multi-device strategy and a rich application portfolio it is clear that RIM has a huge challenge ahead in regaining its key presence in the enterprise,” added Milanesi.