Apple Inc (AAPL.O) sued Ericsson (ERICb.ST) alleging that the Swedish company's LTE wireless technology patents are not essential to industry cellular standards and that it is demanding excessive royalties for these patents.

The iPhone maker said it has not infringed on the patents and does not owe royalties for them.

Apple says that the mobile telecoms gear maker is seeking royalties for the LTE technology calculated as a percentage of the price of the entire smartphone or tablet.

The royalties should be based on the value of the processor chip that includes the technology, Apple said in the lawsuit filed in a federal court in California.

If Ericsson's patents are deemed essential and the court rules Apple has infringed on them, Apple said it wants the court to assign a reasonable royalty rate.

"We've always been willing to pay a fair price to secure the rights to standards essential patents covering technology in our products. Unfortunately, we have not been able to agree with Ericsson on a fair rate for their patents so, as a last resort, we are asking the courts for help," said Apple spokeswoman Kristin Huguet.

Apple and Ericsson currently have a license agreement that covers many of Ericsson's allegedly standard-essential patents. The agreement was signed in 2008 soon after Apple launched the iPhone, according to the court filing.

Representatives at Ericsson were not immediately available for comment outside regular business hours.

The case is in the U.S. District Court of Northern District of California, Apple Inc v. Ericsson, case no: CV-15-0154.