Microsoft has been licensing access to part of its patent portfolio for several years now, offering device makers protection from litigation related to Android and Chrome OS. While Microsoft boasts that more than 70 percent of Android phones sold in the US are covered by licensing agreements, the company has never listed what patents are infringed by Android. Instead, China’s Ministry of Commerce (MOFCOM) has now revealed a list of more than 300 patents and applications held by Microsoft that formed the Chinese approval of the Nokia deal recently.
The list includes 73 standard-essential patents, but there’s also 127 patents that Microsoft claims are implemented in Android. Some on the list, as Ars Technica notes, include patents that Microsoft acquired as part of the Rockstar Consortium to bid on patents from Nortel. All 14 patents used by Microsoft to file a lawsuit against Barnes & Noble are also included. It’s a significant list, and one that Microsoft will have wanted to avoid making public. The software maker has faced criticism over its Android licensing practices, especially from Barnes & Noble, which asked the Justice Department for an antitrust investigation into Microsoft’s attempts to "kill off" Android devices from smaller players with license fees and lawsuits. Microsoft is estimated to earn as much as $1 billion a year from Android-related licensing revenue.