Qualcomm filed two lawsuits against Nokia Corp. in U.S. District Courts on Monday, alleging that Nokia has infringed on five Qualcomm mobile phone patents. The two companies' existing patent licensing agreement will expire April 9, and as the deadline approaches, the firms are increasingly conducting their negotiations through the courts.

In the suits, Qualcomm asked the courts to stop Nokia from selling affected mobile phones, and to order the company to pay damages for phones already sold.

One suit, filed in the U.S. District Court for the Western District of Wisconsin, concerns two patents covering speech encoders used in certain GSM mobile phones to digitize audio signals for transmission.

The other suit, filed in the U.S. District Court for the Eastern District of Texas, dealt with three patents related to the downloading of applications and other digital content over networks using general packet radio service or enhanced data rates for GSM evolution, two technologies for speeding the transmission of packet data in GSM networks.

Qualcomm said it picked those courts, because they adjudicate quickly in patent cases.

Last month, Nokia filed suit against Qualcomm in the Netherlands and Germany, alleging that it shouldn't have to license certain patents from Qualcomm, because it was paying for them in other ways, such as by buying affected components from suppliers that have licensed the disputed technology.

That suit was a response to other patent enforcement actions by Qualcomm, which says it has similar cases pending in the U.K., France, Germany, Italy and China.

The dispute has mostly focused on broadband wireless technologies such as CDMA, but Monday's suits put some of Nokia's GSM phones, so far largely spared by the litigation, under renewed attack.

Qualcomm has previously filed two other patent-infringement lawsuits against Nokia in the United States regarding its GSM, GPRS and EDGE phones, it said.

The IDG News Service is a Network World affiliate.