Android was developed by Google and has become the world's most popular smartphone OS. But Microsoft says it infringes many of its patents, and in 2010 it started a licensing program to collect royalties from Android device makers.
Samsung is one of 25 companies that pay Microsoft to use its technology in Android products. Others include HTC, Acer and Barnes & Noble. Analysts have estimated that Microsoft makes more money indirectly from the sale of Android devices than it does from selling Windows Phones.
"By virtue of the Android licensing program, approximately 80 percent of the Android-based smartphones sold in the U.S. are licensed to use Microsoft's patents," Microsoft says in its complaint.
Neither Samsung nor Microsoft immediately responded to requests for comment.