You must be wondering why Microsoft and Oracle are not trying to get that money from Google but instead from handset makers who use Android. Android operating systems are infringing its intellectual property in some way and Android OS is a Linux-based one.  So since Google is not making any money from the distribution of the Android OS – it’s the device manufacturers that make a profit out of it.

There are allegations on Google that they have infringed on several patents in its Android operating system. Both Oracle and Microsoft  are seeking as much as a $20 licensing fee per device from handset makers that choose to use Android. That’d be roughly double the amount that Google makes. Microsoft is demanding Samsung to cash in $15 for every Android phone sold to date on the base of using several of Microsoft’s patents in these devices. HTC as the first company to give in to Microsoft claims and Samsung is now next.
Oracle has directly asked handset makers, which currently don’t pay anything to use the Google operating system for smartphones, to pay $15 to $20 a handset to license the technology for which the company claims it owns patents, said Deutsche Bank analyst Jonathan Goldberg in an article by IDG New Service on Network World.
 Oracle is also looking to collect money from companies using the Android software just as other software licensing companies do. For example, Microsoft licenses its Windows Mobile 7 software to hardware makers.

One of the benefits of the Google platform is that the Android software has been free. And it’s open nature has allowed hardware partners to add customization to the software to differentiate their products.

The free and open nature of the software has helped the Android platform grow both in the U.S and worldwide markets. In just a few short years, the software has gone from zero market share to becoming one of the most widely use mobile operating systems in the world.

source: cnet