Microsoft has long claimed that it holds a line of patents that are infringed by Google’s operating system, and it has used this portfolio in the past to take legal action against some smaller device releases in the past. However, unlike other users of patents, Microsoft has kept the nature of its portfolio pretty closely held… until now.

You see, Microsoft has built quite a lucrative business from its patent holdings. Estimates put Microsoft earning somewhere between $1b and $2b annually from Android device makers paying royalties to Microsoft. Microsoft itself has claimed that as many as 50% of device manufacturers have licensing deals in place with the tech giant, with estimates now putting that figure as high as 70%. Those who can do a little bit of math have probably realised that Android makes more money for Microsoft than does Microsoft’s own mobile platform… a bit of food for thought.

It seems that Microsoft’s secret patent lists have been revealed though, and in a fairly unlikely place. The Chinese Ministry of Commerce website has been involved in oversight of Microsoft’s purchase of Nokia, and in the process have concluded that Microsoft holds approximately 200 patent families that are necessary to build Android devices.

Most likely, the patent lists and details were produced by Microsoft to the Chinese regulator to help through their regulatory case, and it seems a little more than likely that Microsoft might not be too happy to have the list made public.

Ars has conducted a fairly thorough analysis of the patents, and you’d be well advised to read their original story for the low down, but in a nut shell:

  • There’s two lists published; longer list [MS Word Doc] of 310 patents and patent applications and then ashorter list [MS Word Doc] of just over 100 patents and applications that MOFCOM focused on.
  • The longer list is divided into three sections: 73 patents that are said to be “standard-essential patents,” or SEPs, implemented in smartphones generally, followed by 127 patents that Microsoft says are implemented in Android. 
  • The list includes some patents that Microsoft used against Barnes & Noble, including all 14 mentioned in this 2011 Network World article. Those patents include Nos. 5,889,522 entitled “System Provided Child Window Controls,” and 6,339,780 “Loading Status in a Hypermedia Browser Having a Limited Available Display Area.”
  • It also has many newer and previously unrevealed patents, like 8,255,379 “Customer Local Search,”5,813,013 “Representing Recurring Events,” and 6,999,047 “Locating and tracking a user in a wireless network through environmentally profiled data.”
  • Nortel patents now owned by Microsoft include 5,982,324, which describes combining GPS with cell signals in an “efficient position location system” said to be used in Android phones. More Nortel patents are in the “general smartphone” section, such as No. 6,430,174, which describes a communication system that supports simultaneous voice and multimedia.

When approached about the patent list being published, Microsoft told Ars it had no comment to offer, besides what it had said previously in its blog post announcing the Microsoft-Nokia deal (in other words, next to nothing).

Source: Ars.