3G cellular standards and patents

At the beginning of 2004, the standards for third generation (3G) cellular technology were embodied in 483 Technical Specifications published by the two Partnership Projects: 3GPP and 3GPP2. Corporate members of the Partnership Projects are encouraged to identify intellectual property that is essential to implementing the standards. We have studied 7,796 patents and patent applications declared essential to the two standards. The patents are clustered in 887 families, where each family covers one invention. Three quarters of the declared patents are assigned to four companies. A preliminary evaluation of one patent from each family suggests that approximately 21% of the declared patents are actually essential. This paper presents the distributions of patents declared essential and patents judged essential according to technical category and patent ownership.