Motorola Mobility — a subsidiary of the Motorola parent company — has filed a lawsuit in multiple courts in the US alleging that Microsoft is infringing on 16 of its patents.
The patent-infringement complaints from Motorola — filed on Wednesday — claim that Microsoft PC and server software, its mobile OS and Xbox products all infringe on patents.
Motorola has launched the countersuit in response to litigation initiated by Microsoft in which the Windows maker claims that Motorola's Android-based mobiles infringe on several of its patents.
Motorola's PC and server claims relate to "Windows OS, digital video coding, email technology including Exchange, Messenger and Outlook, Windows Live instant messaging and object-oriented software architecture", the company said in a statement.
The Xbox complaints centre around Microsoft's implementation of digital video coding, Wi-Fi technology and graphical passwords on the games console.
Motorola has requested compensation from Microsoft for the claimed past infringement and has asked it to cease using the patented technology in its products. The claims were lodged with the US District Courts for the Southern District of Florida and the Western District of Wisconsin.
"We are committed to protecting the interests of our shareholders, customers and other stakeholders and are bringing this action against Microsoft in order to halt its infringement of key Motorola patents... we will continue to do what is necessary to protect our proprietary technology," said Kirk Dailey, corporate vice president of intellectual property at Motorola Mobility, in the statement. "It is unfortunate that Microsoft has chosen the litigation path rather than entering into comprehensive licensing negotiations," he added.
In response, Horacio Gutierrez, corporate vice president and deputy general counsel of intellectual property and licensing for Microsoft, said that the company was still reviewing Motorola's filing.
"This move is typical of the litigation process and we are not surprised," said Gutierrez. "We remain confident in our position and will continue to move forward with the complaints we initiated against Motorola in the US District Court for the Western District of Washington and with the International Trade Commission (ITC)."
Microsoft's original complaint — filed on 1 October — alleges that several Android-based Motorola handsets infringe on nine Microsoft-controlled patents that cover smartphone functions such as syncing email, calendar and contact information, as well as the way in which applications are notified about battery and signal changes.
The Redmond-based company also slapped Motorola with a second patent-related claim on Wednesday, when it alleged that Motorola's royalty fees were too high on patent licences that it owns, specifically those relating to the wireless and video-coding technology used in the Xbox.
Motorola is fighting patent battles on a number of fronts. On 1 November Apple began patent proceedings against Motorola over claims that its Android phones infringe on Apple-owned multitouch and touchscreen patents.