Nokia has filed claims in the US and Germany saying that products from HTC, Research In Motion (RIM) and ViewSonic infringe a number of the company's patents, it said on Wednesday.
Nokia has filed actions against all three companies in Mannheim's and Munich's respective regional courts.
Nokia has also filed complaints against HTC before the US International Trade Commission (ITC), the Federal District Court of Delaware and the regional court in Düsseldorf. RIM will also have to dispatch its lawyers to Düsseldorf for a Nokia lawsuit filed there, while ViewSonic's legal team have to defend the company against a suit in Delaware.
In total, 45 patents are included in one or more of the actions, according to Nokia. They are related to a variety of software and hardware features, including power management, multitasking, navigation, data encryption and the retrieval of email attachments on mobile phones.
"We'd rather that other companies respect our intellectual property and compete using their own innovations, but as these actions show, we will not tolerate the unauthorised use of our inventions," Nokia said in a statement.
The company has mostly stayed out of the current patent wars, which have mainly been between the Android camp and Apple.
But royalties from its approximately 10,000 patent families is an important revenue source for the company. When reporting on its first quarter financial results, Nokia estimated that its current annual royalty income run-rate is about €500 million (£406 million).
Also, last year Nokia settled an almost two-year long legal battle with Apple, which resulted in Apple having pay a lump sum and ongoing royalties.
RIM declined to comment on the litigation. HTC and ViewSonic didn't immediately reply to questions about the proceedings.