The Microsoft/Android war: Which patents are at stake?

You may already know Microsoft has forced five Android vendors to pay royalties each time they ship a device, and is suing Motorola and Barnes & Noble in cases that claim Android steals Microsoft intellectual property.

Exactly which patents are supposedly violated by Google's Android mobile OS? Microsoft isn't revealing the details in cases settled without a lawsuit, including agreements with HTC, Velocity Micro, General Dynamics, Onkyo and Wistron.

against Barnes & Noble detail more than a dozen patents Microsoft claims Android devices violate. Let's take a look first at a Microsoft complaint filed Oct. 1, 2010, with the U.S. International Trade Commission, which describes nine patents Motorola allegedly infringes upon. But legal documents filed last October in the ongoing case against Motorola and in March of this year.

Patents 5,579,517 and 5,758,352, issued in 1996, "relate to implementing both long and short file names in the same file system," Microsoft says. The complaint goes on to mention the FAT16 file system used by MS-DOS and early versions of Windows. 

Microsoft claims the Motorola Droid 2, the Droid X and numerous other Motorola Android phones violate these and other patents.

Next on the list is U.S. Patent No. 6,621,746, which was issued in 2003 and relates to a monitoring system that determines when to erase data from flash memory devices.

PATENTED: Microsoft patents 'record button on a computer system'.

Microsoft's Patent no. 6,826,762 from 2004 covers APIs related to cellular technology, including one that lets applications "issue commands without needing knowledge of the cellular telephone's underlying radio structure and without needing specific knowledge of the radio network's specific commands."

More patents include:

• No. 6,909,910 from 2005 for "managing changes to a contact database."

• No. 7,644,376, issued in 2010 to cover an API that lets mobile apps learn about state changes in the device.

• No. 5,664,133 from 1997 covering "context sensitive menu system/menu behavior," known more generally as a graphical user interface that lets users "quickly and easily select/execute the desired computer resource."

• No. 6,578,054 from 2003 covering online and offline transmission of data through methods that "eliminate data transmission and allow multiple copies of data to be synchronized via incremental changes."

• No. 6,370,566 from 2002, with the self-explanatory title, "Generating Meeting Requests and Group Scheduling From a Mobile Device."

Microsoft goes on to claim Motorola "unlawfully sells... devices, associated software, and components thereof that infringe the Microsoft patents," and even that "Users making routine use of the Motorola products also infringe the Microsoft patents."

In supporting documents, Microsoft details aspects of the Motorola Droid 2, noting the existence of flash memory, a calendar and other characteristics that Microsoft claims violate intellectual property. The patents are also detailed in Microsoft's complaint against Motorola in the U.S. District Court in Seattle.

Moving on to the complaint against Barnes & Noble, Microsoft claims the Android-based Nook e-readers infringe on five patents. These include:

• No. 5,778,372 from 1998, titled "Remote Retrieval and Display Management of Electronic Document with Incorporated Images," covering a browser that initially displays electronic documents without background images so they can be loaded more quickly.

• No. 6,339,780 from 2002, titled "Loading Status in a Hypermedia Browser Having a Limited Display Area," referring to a temporary graphic element that displays while a browser is loading content.

• No. 5,889,522 from 1999, titled "System Provided Child Windows Controls," covering a dynamic link library for implementing window controls in an operating system.

• No. 6,891,551 from 2005, titled "Selection Handles in Editing Electronic Documents," a method of highlighting and selecting elements in documents with the ability to resize and drag selections.

• No. 6,957,233 from 2005, titled "Method and Apparatus for Capturing and Rendering Annotations for Non-modifiable Electronic Content," letting users select objects on pages they otherwise cannot edit, and storing annotations "separately from the non-modifiable portion of the file."

Clearly, Microsoft is asserting a broad range of patents against vendors that build Android-based products. In addition to suing Motorola and Barnes & Noble, Microsoft is reportedly demanding $15 from Samsung for every Android smartphone it sells.

Although a quick summary of these patents may make the technologies seem vague or obvious, Microsoft has to prove that products infringe all aspects of a patent to win in court. Given that a deep-pocketed vendor like HTC already settled with Microsoft and is paying Redmond each time it sells an Android phone, it would seem Microsoft's lawyers can be quite convincing.