Apple begins its UK Supreme Court appeal on Monday. The company is challenging a ruling requiring it to pay $502 million to Optis Cellular Technology.

The legal battle centers on standard-essential patents for 3G and 4G mobile technology used in Apple devices. A lower court initially set the royalty rate at $56.43 million.

The Court of Appeal later increased the award to $502 million plus interest. The dispute focuses on determining fair, reasonable, and non-discriminatory (FRAND) royalty rates.

The Supreme Court's decision could redefine how global licenses for essential technologies are valued and negotiated.