With Lumia sales still unable to fill the coffers, Nokia has turned to its rich patent portfolio as an extra source of income.
Nokia is suing HTC, RIM and Viewsonic for patent infringement in the USA and Germany. To be more specific, Nokia filed a complaint against HTC with the US International Trade Commission and another one against HTC and Viewsonic with the Federal District Court of Delaware. In Germany Nokia is suing HTC and RIM in Dusseldorf and all three companies in Munich and Mannheim.
According to Nokia the total number of infringed patents is 45. Here is the official statement about what patents are actually in question.
"Nokia proprietary innovations protected by these patents are being used by the companies to enable hardware capabilities such as dual function antennas, power management and multimode radios, as well as to enhance software features including application stores, multitasking, navigation, conversational message display, dynamic menus, data encryption and retrieval of email attachments on a mobile device."
As you can see Nokia is preparing for a fight, and probably so must HTC, RIM and Viewsonic.