The Impracticality of Priority Right Claiming in Patent Land Rush: A Case Study of Invalidation of a Patent in China

In recent years, some major players in telecom field have initiated a series of patent infringement lawsuits against numerous terminal manufacturers in China. In response, Chinese terminal manufacturers have launched patent invalidation proceedings against their multiple communication standard essential patents globally. This “patent war” has garnered significant attention from professionals in the telecommunications and legal industries.

In June 2022, a Chinese standard essential patent held by a telecommunications industry leader was declared invalid in its entirety by the China National Intellectual Property Administration’s (CNIPA) for lack of inventive steps, primarily rooted in the non-establishment of priority claimed. Specifically, the patentee submitted its first filing before the United States Patent and Trademark Office (USPTO), including an original embodiment, and seeking a broad scope of protection. In a subsequent PCT application, the patentee claimed priority of the US application and introduced a new embodiment, also claiming a broad scope of protection similar to that in the US priority application. However, while the new embodiment introduced in the PCT application fulfills the requirement of enablement, the original embodiment recorded in the US priority application was found unworkable upon later verification.

Having outlined the general scenario, we will now focus on a comprehensive analysis of this case. The objective of this invention is to indicate a newly introduced 64QAM modulation technique while utilizing the current coding method and a single High-Speed Shared Control Channel (HS-SCCH) structure. In simpler terms, the goal is to enable 64QAM without altering the original encoding method, while ensuring precise acquisition of High-Speed Physical Downlink Shared Channel (HS-PDSCH) code channel information for accurate data reception and decoding. In independent claim 1 of this Chinese patent, a generic technical approach is defined as follows:

“... interpreting the 7 channelization code-set information bits in HS-SCCH part 1 structure such that only 6 bits of the channelization code-set information bits are interpreted as code-set information and one bit of the channelization code-set information bits is interpreted as selection between 16 QAM and 64 QAM.”

The US priority document recorded independent claim 1 and an only embodiment corresponding to this generic technical approach defined in claim 1, namely embodiment 2 in the description. In this embodiment, the existing value range of the code-set information is approximately halved, aiming to represent the code-set information that originally required 7 bits using only 6 bits. However, the US priority document manifests critical deficiencies in embodiment 2. Notably, the formula used in embodiment 2 to calculate the specific value of the 6 bits not only contains errors but also fails to unambiguously determine the HS-PDSCH code channel information from the calculation result. Consequently, this renders it incapable of achieving its intended technical effect.

In the subsequent PCT international application, a new embodiment has been introduced, designated embodiment 1. This embodiment offers a particular technical solution, which falls under the generic subject matter defined in claim 1. It involves using additional information to recover the stolen 1 bit, without compromising the value range of the code-set information. This approach ensures the accurate acquisition of HS-PDSCH code channel information, allowing for correct data reception and decoding. It is, therefore, evident that embodiment 1 in this PCT international application is the true avenue through which this patent can genuinely fulfill the objectives mentioned above of the invention.

What prompts this new embodiment to be introduced in the PCT application, but not recorded in the US priority document, you may wonder? The rationale behind these amendments to the application becomes evident upon closer examination. In telecommunications, it was discovered that the technical specification 3GPP TS 25.212 V7.4.0 comprehensively documented embodiment 1. Notably, the release date of this specification falls conveniently between the priority date of the patent and the filing date of the PCT application. This sequence of events sheds light on the patentee’s strategic intent. It became apparent that, on the earlier priority date, the patentee sought to establish an ambitiously broader protection scope that however, in practice, was unfeasible. Subsequently, the patentee incorporated technically viable solutions from industry standards within this broader protection scope in later applications. This strategy may be suspectedly considered a “patent land rush”.

A concern was raised by intellectual property authority and some professionals that should such patent application strategies be deemed acceptable, it would fundamentally undermine the original purpose of the Paris Convention in establishing the patent priority system. This approach would be perceived as unfair to the dedicated inventors and researchers who make significant contributions to technological progress and the interests of the public.

China’s patent law only stipulates that the later and earlir applications serving as the basis for priority must be of “the same subject matter”. However, when it comes to situations where the earlier application contains all the contents of an independent claim present in the later application but is not implementable, there is no clear guidance on whether priority should be recognized. Therefore, addressing these vaguenesses in patent applications within the framework of China’s existing laws became a primary focus.

In the Decision of Invalidation No. 56283, the CNIPA concluded that “in the absence of a specific implementable embodiment in Evidence 5 (i.e., the US priority document) capable of enabling the technical solution of independent claim 1 of the patent, the subject matter of claim 1 in the present patent is overly generic or unclear in Evidence 5. As a result, those skilled in the art are unable to implement this technical solution based solely on the disclosure in the US priority document. The technical solution of claim 1 thus lacks a clear and unambiguous documentation in the earlier application ... The applicant could only enable this specific solution by incorporating a detailed description of a particular technical feature in the later-filed PCT application. Therefore, the technical solution of claim 1 of this Chinese patent cannot enjoy benefit of priority from the earlier-filed US application.”

As can be seen from the above, while the CNIPA does not explicitly require that the priority document must be sufficicently disclosed, it does prescribe that the technical solution claimed as a priority in the document should not be vague and ambiguous but rather substantially “clear”. In other words, even if a generic technical solution has been recorded in the priority document in verbatim, but the embodiments provided threrein demonstrating its implementation cannot be put into practice, then such a generic technical solution cannot take advantage of the priority right.

It has come to our attention that in the subsequent proceedings of opposition for the European counterpart, the minutes of the oral hearing in July 2023 held by the Boards of Appeal of the European Patent Office (EPO) stated: “… the Chair gave the Board’s conclusion that the priority was not valid because the disclosure in the priority document was not an enabling disclosure.” This indicates that the EPO and the CNIPA share a consistent view regarding validity of priority right claiming for this patent and its counterparts.

We also have observed that in Japan, the United States, and Europe, there are relevant provisions addressing such situations. In Japan, the Examination Guidelines for Patent and Utility Model, Section 3.1.3, Chapter 1, Part V, and the Examination Handbook for Patent and Utility Model, Section 5107 of Chapter 1, Part V provide a summary of circumstances in which the effect of priority claim may not be recognized. The latter handbook provides that:

“If the statement of an embodiment is added to the application documents filed in the first country, and the application is filed in Japan, which makes the claimed invention filed in Japan enabled, it will mean that new matter is added in relation to the matters stated in the application documents as a whole filed in the first country. With regard to the claimed invention filed in Japan, therefore, the claim of priority under the Paris Convention does not take effect.^[1]”

In the United States, Section 211.05 Sufficiency of Disclosure in Prior-Filed Application [R-08.2017] of the Manual of Patent Examining Procedure also stipulates:

“To be entitled to the benefit of the filing date of an earlier-filed application, the later-filed application must be an application for a patent for an invention which is also disclosed in the prior application ...; the disclosure of the invention in the prior application and in the later-filed application must be sufficient to comply with the requirements of 35 U.S.C. 112(a) except for the best mode requirement.^[2]”

Although Europe does not explicitly define this matter in its regulations, parallel cases can be found. In Decision Case No. T 0843/03, it was emphasized that:

“Further, the priority document has to provide an enabling disclosure ... This is well within the concept of ‘the same invention’ of Article 87(1) EPC as an incomplete technical disclosure cannot be seen as being ‘the same’ as a complete one.^[3]”

In Decision Case No. T 409/90, it was noted that:

“The fact that a claim in a priority document is broad enough to cover (or “comprehends the possible provision of”) specific subject-matter which is filed for the first time in a later application, cannot by itself be sufficient evidence that such a subsequently filed subject-matter has already been disclosed in the priority document, or that subsequent claims based on that later filed subject-matter still define the same invention as that which is the subject of the priority document.^[4]”

From the above, it becomes clear that various countries and regions share a consistent understanding of the priority right claim system. Its fundamental purpose is to provide convenience for applicants to seek patent protection cross different jurisdictions. While applicants can use the priority rights system elements to refine their inventions, this refinement calls for a more cautious approach, as it may be precarious especially there could be a possibility of being considered a technically “patent land rush”. It would thus be highly advisable for applicants to ensure the technical feasibility of their inventions in their first filings to legitimately and reasonably secure patent rights in the original and subsequent jurisdictions.

[1] The Examination Handbook for Patent and Utility Model in Japan. Page 7.

https://www.jpo.go.jp/e/system/laws/rule/guideline/patent/handbook_shinsa/document/index/05_e.pdf

[2] The Manual of Patent Examining Procedure in the US.

https://www.uspto.gov/web/offices/pac/mpep/s211.html#ch200_d1ff71_250c8_de

[3] Decision Case No. T 0843/03 by Boards of Appeal of the European Patent Office. Page 8.

https://legacy.epo.org/boards-of-appeal/decisions/pdf/t030843eu1.pdf

[4] Decision Case No. T 409/90 by Boards of Appeal of the European Patent Office. Page 11.

https://legacy.epo.org/boards-of-appeal/decisions/pdf/t900409ex1.pdf