Sony launched their first handheld gaming console five years ago.
Sony PlayStation Portable is currently the only challenger to the Nintendo DS series. Though Apple iPhone has also become a player in this segment.
Apple iPad would soon join the group enabling users to play casual and high profile games on a handheld device.
Sony has stated that they have sold 60 million systems worldwide out of which around 17 million were sold in the US market alone.
Nintendo DS dominates this segment of the market with 125 million units sold globally.