Microsoft is announcing today that BlackBerry maker, Research In Motion, has signed a patent licensing agreement for the software maker's Extended File Allocation Table (exFAT) file system on certain BlackBerry devices. exFAT is a proprietary file system designed and developed by Microsoft — increasing the size of files and transfer speeds on flash storage drives. A number of companies have integrated the file system into devices such as mobile phones, PCs, and cameras.

RIM is the latest big name to licence Microsoft's exFAT system. Microsoft's David Kaefer says the RIM deal "highlights how a modern file system, such as exFAT can help directly address the specific needs of customers in the mobile industry." Microsoft's previous legacy file system, known as File Allocation Table (FAT), is at the center of a dispute between Motorola and Microsoft in Germany. Earlier this year, Microsoft won a request to ban certain Motorola Android deices for infringing Microsoft's FAT patent.

So why the PR for a such a seemingly minor deal? Microsoft appears to be sending another signal to Google and Motorola that litigating core patents like exFAT isn't worth the cost. Microsoft's Brad Smith and Frank Shaw both made it obvious earlier this year that Microsoft feels licensing agreements are the way forward instead of lawsuits. Ultimately, the approach drives the cost of Android up and offers manufacturers protection from intellectual property litigation from Microsoft over their use of Android.