Nokia fires another lawsuit at Apple

The increasingly complex web of litigation surrounding the iPhone and iPad took another twist today when Nokia sued Apple, again, for patent infringment.

The Finnish phone maker said it is suing Apple in Wisconsin, claiming the two devices infringe upon five of its mobile patents.

The patents in question cover speech and data transmission, using positioning data in apps and types of space-saving antenna configurations, Nokia said.

It's at least the fourth legal action Nokia has started against its rival in the last year.

It filed patent infringement suits in October and January, and lodged a complaint with the US International Trade Commission in December.

Apple, for its part, sued Nokia in December too, claiming infringement on 13 patents. It's also filed a case with the ITC.

Patent cases, unless they are resolved out of court, take years to process. ITC complaints generally take rather less time to sort through.