Samsung Electronics filed four additional patent claims against Apple on Friday in a German court, while also going to trial over three other patents that the Korean company alleges are infringed.
Two of the patents are related to telecommunications standards, and the other two are related to "the utility of mobile devices," according to a statement provided by Samsung.
Samsung said it has developed technologies and protocols "for the efficient and reliable functioning of telecommunications networks and devices."
"While Samsung has at all times met its obligations to the fair licensing of its telecommunications standards-related patents, Apple has infringed by using without license Samsung's intellectual property in its mobile devices," the company alleged.
One of those four patents relates to how "smileys" are entered into mobile phones, said Florian Mueller, a patent expert who closely follows litigation in the mobile industry.
Samsung and Apple representatives were in Mannheim Regional Court on Friday for trials related to three German patents, said Mueller, who attended the hearing. Verdicts will be released early next year, he said. Samsung filed those claims with the court in April.
Court officials contacted in Mannheim could not comment on the proceedings. Apple officials could not be immediately reached.
Samsung, Motorola, Apple, Microsoft and other companies have been engaged in a flurry of patent-related legal proceedings in the mobile arena.
Last week, the Mannheim Regional Court ruled that Apple's iPhone and iPad devices infringe a Motorola patent and issued an injunction against sales of the products in Germany.
Apple could appeal the injunction. But before the court enforces it, Motorola would have to post a €100 million (US$134 million) bond.