Thanks to Chinese regulators, Microsoft's acquisition of Nokia may have cost more than just the $7.2 billion sticker price.
As part of the regulatory approval process, the Chinese government has revealed 310 patents Microsoft may use to extract licensing revenue from Android device makers. Although Microsoft has avoided disclosing these specific patents in the past, a couple of lists are now freely available as .DOC files from the Chinese Ministry of Commerce website. The two lists were first spotted by Ars Technica.
The longer of the two lists is divided into three sections. The first section includes 72 patents listed as "standard-essential patents," which are mainly related to networking and found in most smartphones. Another 127 patents are listed as being "implemented in 'Android,'" and an "other" section lists 42 more patents and 68 patent applications.
It's worth noting that Microsoft doesn't use all of these patents when it goes to war with an Android vendor. A 2010 lawsuit against Motorola, for instance, included just nine patents, and a 2011 lawsuit against Barnes & Noble included five patents. The list of 310 patents may give Android vendors a better sense of what ammunition Microsoft has stored up.
As Ars points out, both the first and second sections contain patents that Microsoft acquired as part of Rockstar Consortium, a group that includes Apple, Blackberry, Ericsson, and Sony--but not Google. The consortium sued Google and Samsung last October.
Over the last four years, Microsoft has struck patent licensing deals with Android vendors large and small, including Samsung, HTC and Compal. Although the terms of these agreements and the exact patents involved have never been disclosed, recent estimates suggest that Microsoft rakes in more than $2 billion per year from Android device sales.