Background
This case was selected by the Reexamination and Invalidation Department of China National Intellectual Property Administration (CNIPA) as one of the Top 10 Reexamination and Invalidation Cases of Year 2024. The patent involved is titled "Carrier Aggregation Feedback Method, Device and System" (Patent No.: ZL201210137097.1), with Datang Mobile Communications Equipment Co., Ltd. (hereinafter referred to as Datang) as the patentee and Samsung (China) Investment Co., Ltd. (hereinafter referred to as Samsung) as the petitioner for invalidation. During the invalidation proceedings, the patentee amended the claims in response to the petitioner's invalidation request, adding technical features to the independent claims, and thereby maintaining the validity of the patent.
The patent involved relates to cross-generational standards in the communication field. Specifically, it is an improvement on the carrier aggregation feedback method for different frequency bands during the evolution from the 3GPP 4G standard to the 4.5G standard, i.e., from the intra-band carrier aggregation scenario to the inter-band carrier aggregation scenario.
Meanwhile, this case is part of the patent disputes between Datang and Samsung. In February 2023, Datang filed an infringement lawsuit against Samsung with the Fuzhou Intermediate People's Court in Fujian Province, China, and also initiated an infringement lawsuit with the Munich Court in Germany. In July 2023, Samsung began filing multiple invalidation requests in China (this case is one of the series of cases where Samsung filed invalidation against Datang's patents in China), and in October 2023, it started filing invalidation requests against multiple patents of Datang in the United States and other regions. After a series of lawsuits between the two companies in multiple countries, they reached a settlement in June 2024. The global patent litigation between the two companies has had a profound impact on the patent licensing rules in the communication industry, affecting numerous innovation entities.
Case Introduction
Claim 1 defines, in the inter-band carrier aggregation scenario of 4.5G, how to determine the feedback subframe number under different aggregated carrier configurations according to the configuration table of the 4G standard, as well as how to determine channel resources based on the feedback subframe number and perform feedback. The TDD uplink/downlink configuration of carriers through system information configuration follows the provisions in the 4G standard, while the technical feature added on the basis of the 4G standard provisions is that, when different carriers have different configurations in inter-band carrier aggregation, the feedback subframe number M is determined as the maximum value of the subframe numbers requiring ACK/NACK feedback in the current uplink subframe on each carrier, which are determined according to the TDD uplink/downlink configuration corresponding to each carrier.
The evidence submitted by the petitioner includes two categories: technical solutions based on the 4G standard and the 4.5G standard. In one of the main combinations of evidence, the petitioner argues that: Evidence 3 (WO2012/044115A2) based on the 4G standard discloses the relevant technical features of determining the maximum value M from the configuration table; the relevant technical features involving the 4.5G scenario are disclosed in other evidence based on the 4.5G standard; and it is obvious to a person skilled in the art to obtain the technical solution claimed in Claim 1 by combining the above two categories of evidence.
Regarding the above combination of evidence, the collegial panel basically accepted the petitioner's statement on the closest prior art, and determined that Evidence 3, the closest prior art, is a technical solution based on the 4G standard, while the patent involved is a technical solution applied to the inter-band carrier aggregation scenario. Therefore, the cross-generational nature of the patent involved relative to Evidence 3 is reflected in the change of technical scenarios.
Specifically, the collegial panel pointed out that Evidence 3 is a technical solution based on the 4G standard, with the scenario of intra-band carrier aggregation, and the specific technical means is to determine the feedback subframe number according to the maximum value among the subframe numbers actually used by multiple carriers; the feedback subframe number determined by Evidence 3 is actually used, while the patent involved determines the maximum value according to the configuration table, so the basis for selecting the maximum value is different between Evdience 3 and the patent involved. In addition, Evidence 3 selects the maximum value after the actual start of data transmission, while the patent involved selects it during configuration, so the selection timing is also different. Therefore, Evidence 3 does not disclose the relevant technical features of determining the maximum value M from the configuration table. Based on the above distinguishing features, the collegial panel determined that the technical problem actually solved by the patent involved relative to Evidence 3 is to realize information feedback in inter-band carrier aggregation, so as to improve the efficiency of information feedback.
The collegial panel further pointed out that based on analysis of the patent involved and the content disclosed in Evidence 3, Evidence 3 is in the scenario of intra-band carrier aggregation, where there is no problem of different configurations under inter-band carrier aggregation, and no operation is required in the configuration stage. However, the patent involved solves the problems caused by different configurations in the inter-band carrier aggregation scenario, which is a new problem in the new scenario and needs to be solved in the configuration stage. It can be seen that Evidence 3 is irrelevant to the technical problem to be solved by the patent involved, and such a problem does not exist in Evidence 3, that is, the technical problem to be solved by the invention does not exist in the prior art. Therefore, it is often lack of motivation for a person skilled in the art to improve on the basis of the prior art to obtain the invention.
As for the distinguishing technical features, among the evidence based on the 4.5G standard that the petitioner advocates to combine, Evidence 4 (3GPP TSG RAN WG1 #68 Summary Report v1.0.0 (R1-120951)) mentions the scenario of inter-band carrier aggregation. However, the collegial panel determined that it does not disclose specific technical means and is insufficient to teach a person skilled in the art to obtain the technical solution of the patent involved. The petitioner also advocates that Evidence 10 (CN102291227A) discloses that in the inter-band carrier aggregation scenario, when carriers of different frequency bands have different configurations, a pre-specified number of subframes is used to transmit feedback information. However, the collegial panel believes that it is also different from the above distinguishing technical features defined in Claim 1, that is, Evidence 10 adopts a different solution from the patent involved.
Based on the above reasons, the collegial panel determined that none of the prior art discloses the relevant technical features of determining the maximum value M from the configuration table, and determining the maximum value from the configuration table is an indivisible technical feature that cannot be obtained by simply piecing together technical features. Moreover, there is a lack of motivation for combination between the existing technologies involving different generational standards. A person skilled in the art cannot obviously obtain the technical solution protected by the patent involved based on the above prior art. However, the patent involved solves the new problems arising in the cross-generational new scenario by determining the maximum value from the configuration table, and achieves the beneficial technical effect of improving the efficiency of information feedback. Therefore, the patent involved has prominent substantive features and significant progress relative to the prior art.
Insights
From the invalidation decision of the Reexamination and Invalidation Department, for the determination of inventiveness of patents involving communication standard patents, the key lies in identifying, relative to the prior art, which aspects of cross-generational changes the improvements of the target patent belong to, such as changes in system architecture, technical scenarios, or user applications. The update cycle of communication technologies from 1G to 2G and then to 3G is long. Cross-generational changes usually involve changes in system architecture, which often require the construction of new base station equipment. However, starting from the development of 4G, with the explosive growth of the mobile Internet, the update cycle of standard versions has shortened, and downward compatibility has become stronger. Many cross-generational standards only involve changes in technical scenarios and user applications. For example, how to transmit more information within limited frequency bands and achieve higher-speed data transmission. This requires the adoption of more innovative technologies in spectrum utilization, deployment scenarios, and technical characteristics to achieve these goals.
Secondly, it is necessary to judge the relationship between the technical problem solved by the distinguishing features and cross-generational changes, i.e., whether it is a new problem brought about by cross-generational changes or a traditional problem that has always existed in the development of communication technologies. When considering motivation，we should distinguish between the inheritance and iteration of technical features. Inheritance refers to the provisions in the prior standards followed for downward compatibility, while iteration refers to the replacement of provisions in the prior standards or added content. On this basis, we can judge whether the prior art provides motivation and whether there is a motivation for combination between the prior art.
For example, determine whether there are the same or similar problems in the prior art, thereby motivating those skilled in the art to improve the prior art; and determine whether the prior art provides logical guidance on the direction of improvement, enabling those skilled in the art to make improvements in that direction.
Therefore, in the invalidation case, the patent involved introduced a new 4.5G scenario across generations, solving new problems faced in the new scenario. Evidence involving the old 4G scenario does not have the new problems faced in the new scenario, and evidence involving 4.5G does not disclose specific solutions or discloses different solutions. Considering comprehensively whether the prior art teaches the possibility of combining relevant features in two different scenarios, and the differences in the effects produced by relevant features in their respective scenarios, these differences lead to the inability to combine the prior art of old and new scenarios due to their respective scenario limitations, so there is no motivation for combination. Therefore, the patent possesses the inventiveness.
In drafting cases, for applicants, it is suggested conducting sufficient searches when drafting to obtain relatively accurate "prior art", then define independent claims, and reasonably arrange the structure of dependent claims based on optional embodiments to ensure the stability of the patent right.
For invalidation petitioners, searching for strong evidence is also the key to achieving the invalidation result. Based on the retrieved prior art, determine the technical problem solved by the target patent, and then combine the evidence to demonstrate the obviousness of the technical solution, thereby convincing the collegial panel to achieve invalidation.
