Just when you thought the mobile patent wars might be behind us, Qualcomm and Apple seem determined to keep them going.

Qualcomm raised the stakes in its patent battle with Apple Thursday afternoon, suing it for patent infringement and asking the U.S. International Trade Commission to bar the sale of iPhones with anything other than a Qualcomm wireless modem chip from entering the country. Given its hand, the chip company probably doesn’t have much of a choice: Apple’s decision earlier this year to stop paying Qualcomm royalties alongside its own antitrust lawsuit claiming Qualcomm’s business model is unfair is a fundamental threat.

The International Trade Commission is a common destination in the early stages of a patent dispute. The federal agency doesn’t rule on the validity of a patent itself, but can take steps to prevent products from being imported into the U.S., and like most tech products, the iPhone is largely made in China. An ITC ruling can shift the balance of power in settlement negotiations, which is where the vast majority of these cases wind up anyway.

Qualcomm also sued Apple for patent infringement in San Diego asserting six patents for wireless technology, but that case will wait until the after outcome of the ITC hearing, which is expected next year, Qualcomm said in a press release. ITC rulings tend to move more quickly than patent trials, according to Bloomberg, which can take years to resolve.

Apple kicked this whole thing off by suing Qualcomm in January under antitrust law, claiming that Qualcomm’s patent-licensing business model is anticompetitive and hoping to lower the royalty payments it makes to Qualcomm for the chips in the iPhone that connect you to the internet. Apple also asked a judge to determine whether the patents at issue in this case are valid.

Billions of dollars are at issue in this dispute, depending on how the rulings go. If Apple is successful in challenging Qualcomm’s business model, it won’t be the last company to try and renegotiate its licenses with Qualcomm, which took in $26.3 billion in revenue last year. Qualcomm is also facing a challenge over its business model from the U.S. Federal Trade Commission.

And obviously, Apple can’t let a court prohibit nearly half the iPhones it sells in the U.S. from coming ashore. That would force it to consider settlement talks should the ruling go in Qualcomm’s favor, or double down on its efforts to get the patents invalidated.

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.