The Apple-Nokia patent fight carries on, this time with Nokia extending its complaints to Apple's gadget du jour, the iPad. Nokia filed a lawsuit in a Wisconsin federal court on Friday, asserting that Apple's iPhone and iPad 3G infringe on five patents that cover a broad range of technologies.

Nokia claims that Apple's products, including the iPad WiFi + 3G, are using Nokia IP related to enhanced speech and data transmission, the use of positioning data in applications, and compact, increased-performance antenna designs. This complaint follows multiple suits filed by Nokia in recent months, all of which concern Apple's use of various technologies that Nokia claims patents on. These include 3G, 2G, and WiFi networking, built-in cameras, click wheels, and some more complex technologies like a "programmable voltage-controlled oscillator."

Apple countersued Nokia in January, claiming that Nokia phones infringe on 13 Apple patents. Nokia responed by asking that the countersuit be dismissed. The ITC is also investigating the whole IP mess, and the suits are unlikely to go to trial before 2012. Analysts have noted that Nokia likely just wants royalty payments from iPhone (and now iPad) sales, rather than a full injunction. This would afford Nokia a 1 to 2 percent cut from each sale, or about $6-12 per iPhone and $10-17 per iPad. On that point, so far, Apple hasn't budged.