Apple is suing Ericsson alleging that the Swedish telecoms equipment giant is charging excessive royalties for LTE wireless technology patents.
Apple is arguing that the patents are not essential to industry cellular standards and that Ericsson is demanding too much.
It is understood that Ericsson is seeking royalties for the LTE technology calculated as a percentage of the price of an iPhone or iPad.
Apple argues that instead the royalties should be based on the value of the processor that includes the technology.
According to Reuters Apple said that it was always willing to pay a fair price for the patents but so far has been unable to come to an agreement with Ericsson.
The two companies currently have a license agreement that covers many of Ericsson’s wireless patents.
If the court in Northern California deems the patents in question to be essential and that Apple has infringed them, the Californian tech giant wants the court to assign a reasonable royalty rate.