Abstract: Standard-essential patents (SEPs) are the core of competition in technology-intensive industries such as a new generation of information technology. The effective licensing and implementation of SEPs is an important driving force for realizing economic digital transition and upgrading. Although the International Standards Organization has proposed a governance system of international rule based on FRAND principle as the core for the licensing of SEPs, litigation disputes focused on the determination of the FRAND license royalties sweep the globe because the FRAND principle is vague and has no mandatory binding force. In order to explore the factors affecting the determination of the FRAND license royalties, an empirical study is analyzed based on the theory of patent value evaluation and judicial practice. The factors affecting the determination of the FRAND license royalties are studied from the three dimensions of the determination of patent value: commercial factors, technical factors and legal factors. In order to analyze the influencing factors of the determination of license royalties for SEPs encumbered FRAND, this article first systematically examines the influencing factors of the determination of FRAND license royalties from the above three dimensions. On the basis of theoretical analysis, 17 typical cases from different jurisdictions are selected for empirical research, including the feasibility and difficulties of application of each factor, identifying the main influencing factors and their approaches to measure for exploring the way of determining FRAND license royalties. The conclusions of this paper reveal that commercial factors, technical factors, and legal factors are sequenced according to the frequency from high to low when considering the three major categories. Specifically, first, among commercial factors, comparable licenses are the preferred way to determine FRAND license royalties because this method can reflect the economic value of the patented technology in the market, respect for the principle of freedom of contract, and eliminate the complicated calculation process, which can improve the efficiency of the court trials. However, when faced with barriers such as difficulties, in demonstrating comparability, lack of a sufficient number of comparable agreements and relevant information of cross-licensing or license with preferential terms, this method is not applicable. Second, in terms of technical factors, there are some difficulties of the technical contribution of SEPs to products and the technical contribution of SEPs to standard, such as how to apply entire market value rule or the smallest salable patent practicing unit rule to determine the basis of apportionment, how to calculate the proportion of the number of SEPs involved in the total number of SEPs, and how to adjust the number proportion according to the importance of the SEPs involved, so they are sub-optimal methods. Moreover, the two methods of the patents involved outweigh the utility of alternative technologies and the implementation cost of alternative technical solutions are lack of reference significance because these two technical methods are too difficult to operate. Finally, the legal factors such as avoiding patent hold up and hold out, avoiding royalty stacking are difficult to measure, so they are of less reference significance. However, legal factors can provide a meaningful reference for the choice of calculation methods and the conditions of injunction. Generally speaking, the determination of FRAND license royalties is a very complex issue. Various calculation methods have their own advantages and disadvantages. Above them, the methods of comparable licenses and top-down approach are the most commonly used methods which could be applied according to the details of the case. Based on the above conclusions, this article provides specific suggestions for determining the FRAND license royalties. In short, all calculation methods must be applied selectively or comprehensively case by case to determine a more accurate range of FRAND license royalties and realize the benefits of the parties. 

Key words: FRAND license royalties, standard-essential patent, patent value evaluation, Georgia-Pacific Factor Method