The big idea is to avoid some of the litigation that has dogged rivals in the smartphone market recently.
There are 74 patents that Microsoft has written cheques for including Acacia Research and Access. Access was the outfit that bought PalmSource, the firm behind the Palm operating system, in 2005.
Acacia has several patent claims against Apple, Research In Motion, Samsung, and Motorola. Microsoft was not named in the suit which covered patents covering functions like email synchronization and providing phone capabilities from personal computer devices.
David Kaefer, general manager of intellectual property and licensing at Microsoft told the Wall Street Journal that by efficiently licensing patented innovations from other companies, Redmond was free to develop "great software and we're able to provide our partners and customers peace-of-mind."
Redmond has been becoming more protective about its own patents lately and perhaps it knows that there is money to be made being on the right side of a patent claim rather than defending it.
Microsoft wants to make a comeback in the smartphone stage after messing around for a few years. It does not want licence disputes to stuff it up.