The market share of Windows Phone will double in the next three years, according to the latest report from the market research firm IDC. While shipments of devices running Microsoft's mobile OS will hit the 35 million mark this year, accounting for just 2.7 percent of the market, that figure will jump to 5.6 percent in 2018, when the Redmond-based company is expected to ship around 105 million Windows Phone devices.

Worldwide Smartphone Forecast by Shipments and Value, 2014 and 2018

Shipments in millions of units and Value in US$ Million

  2014 2014 Market Share 2018 2018 Market Share 2014-2018 CAGR
Android 1,060 82.3% 1,498 80.0% 9.0%
iOS 178 13.8% 240 12.8% 7.8%
Windows Phone 35 2.7% 105 5.6% 31.4%
Other OS 14 1.1% 30 1.6% 20.4%
Total 1,288 100.0% 1,873 100.0% 9.8%
Android 255,102 66.6% 275,248 60.9% 1.9%
iOS 116,540 30.4% 152,626 33.8% 7.0%
Windows Phone 7,782 2.0% 19,033 4.2% 25.1%
Other OS 3,480 0.9% 4,862 1.1% 8.7%
Total 382,904 100.0% 451,769 100.0% 4.2%

Meanwhile, Android will continue to dominate shipments in 2018 with 80 percent market share, a slight decline from 82.3 percent in 2014, while iOS will control only 13 percent of volume, compared to 13.8 percent this year. As for the revenue, Apple's mobile OS will have 34 percent of all smartphone revenues, compared to 61 percent for Google's mobile OS. 

"Apple's approach with premium pricing ensures a growing portion of overall revenues despite its declining market share," said Ramon Llamas, Research Manager with IDC's Mobile Phones team. "Meanwhile, Android's multi-faceted approach - with forked versions and low-cost Android One strategy - will produce mixed results, yet it allows deeper penetration into emerging markets."

Worldwide smartphone shipments will reach a total of nearly 1.3 billion units this year, a 26.3 percent increase year-over-year. Looking ahead, the research firm expects 1.4 billion smartphones to be shipped worldwide in 2015, representing a 12.2 percent year-over-year growth rate. The slower annual growth is expected to continue throughout the forecast with unit shipments approaching 1.9 billion units in 2018.

Smartphone prices are also expected to come down in the coming years – the report notes that average selling price will drop to $241 by 2018, compared to $297 this year.

"The impact of upstart Chinese players in the global market will be reflected in a race to the bottom when it comes to price," said Melissa Chau, Senior Research Manager with IDC's Worldwide Quarterly Mobile Phone Tracker. "The biggest question now is how much lower can prices go?"