The ETSI declaration database is the largest of its kind, containing over 555,000 declared patents spanning more than 100,000 patent families. In response to some court rulings that prohibit the enforcement of late-declared patents, many ETSI-declaring companies have adapted their strategies. As a result, patents are now often self-declared at the earliest possible stage, frequently including unpublished provisional or priority numbers. The self-declaration process introduces significant variability, as companies follow completely different approaches when submitting their patents. Companies often submit patent numbers in varying formats and types. Some provide only provisional numbers, while others declare application numbers, grant numbers, and all jurisdictional counterparts. This lack of consistency results in an ambiguous ETSI database, posing challenges for analysis and interpretation. So called top-down analysis to identify a 4G or 5G patent owner’s share can become inherently biased when based on unprocessed data. This can lead to underrepresenting the patent portfolio size of companies that share less information. And it favors those that declare more extensively.
Over the past decade, patent data providers have developed sophisticated rules for matching, cleaning and normalizing patent numbers. This enables them to identify and link many of the declared patents. However, the complexity of this process has deterred some data providers from fully committing to producing accurate patent declaration data. As a result, several 5G patent reports have presented conflicting and often confusing findings. This inconsistency undermines the reliability of such analyses. It creates a distorted view of the true landscape of publicly declared patents.
For many 5G patent experts, the presence of multiple reports on 5G patent ownership with conflicting rankings is a cause for concern. This is especially true when reports consider publicly available ETSI-declared patents where all the data originates from the same public source. If the underlying source for these reports is identical, it stands to reason that their rankings should align. This discrepancy has prompted IP professionals, from both SEP owners and standards implementers, as well as global lawyers and economists, to ask critical questions:
While it is not transparent how certain reports conclude their patent shares, public 4G or 5G rankings may have an impact on SEP licensing. The determination of FRAND rates in more and more cases incorporates a so-called “top-down” approach. The portfolio size of the patent owners is compared to the total patent stack to calculate a 4G or 5G share. Additionally, when assessing the comparability of license agreements, courts are increasingly relying on patent declaration data to determine whether an agreement is truly comparable. Reliable 4G and 5G patent data is playing an ever-growing role in SEP licensing and litigation. As such, patent declaration data integrity is becoming a critical topic.
Companies submit patent numbers in various formats and types, leading to inconsistencies in matching ETSI-declared patent families. Figure 1 highlights the number of non-matched ETSI-declared patent families (INPADOC) by declaring company when relying solely on unprocessed patent number declarations.
The figure underscores how differences in declaration practices across companies significantly affect matching performance. The quality and completeness of patent declarations vary widely among declaring companies. For example, companies like Xiaomi, Lenovo, and OPPO provide clean and consistent declarations, always disclosing all published patent numbers. Notably, companies with a high proportion of provisional or priority numbers in their declarations—such as Ericsson, Qualcomm, Nokia, Huawei, and Intel—show particularly high numbers of non-matched ETSI-declared patent families. This issue poses a critical risk for 4G or 5G patent ownership analysis that fail to rigorously account for all patent number formats. This risks underrepresenting the size of certain companies’ patent portfolios. Without a rigorous and comprehensive matching process, entire patent families may be overlooked. This highlights the importance of rigorous data validation to ensure accurate and equitable 4G and 5G patent analysis.
Another major challenge is that the ETSI database does not comprehensively identify all patent family counterparts for declared patents. One key reason is that ETSI identifies patent family counterparts only at the time of declaration. If a patent is declared before its family counterparts are published, the database is not updated later to include those additional counterparts when they become available in other jurisdictions. Some companies proactively re-declare family counterparts as they are published. Other companies only declare the initial patent application. This practice leaves many global patent family counterparts unaccounted for in the ETSI database. Figure 2 highlights this issue. It shows that 9,244 granted U.S. patent counterparts are missing from the ETSI database, despite the corresponding basis patent being declared. Likewise, a significant number of granted counterparts for Chinese, European, Japanese, and Korean patents are also absent. We conducted the family expansion with consideration of the ETSI IPR Policy. This policy stipulates that when a basis patent is declared, its counterparts are also subject to the FRAND commitment. Here, counterparts are determined based on ETSI’s more restrictive simple patent family definition compared to INPADOC.
Relying solely on ETSI-declared patents introduces a bias in jurisdiction-specific patent analysis. It skews the data based on declaration behavior. This leads to the omission of a substantial number of granted patents, undermining the accuracy and completeness of such analyses. To ensure balanced and reliable rankings, it is essential to account for all family counterparts. This is regardless of their inclusion in the public ETSI database, as long as one family member is declared.
Especially for valuable patents such as cellular SEPs, ownership frequently changes, and in some cases, entire companies may be acquired. If patent ownership data is outdated and such changes are not rigorously tracked in global patent offices, or corporate tree information is not applied and company names are not harmonized, patent owner rankings can become highly inaccurate and misleading. Figure 3 illustrates the significant difference between rankings based on cleaned, normalized, and up-to-date ultimate owner data, identified through corporate trees, versus those relying on raw ETSI-declared company names. For example, figure 3 shows that a significant portion of the Intel portfolio acquired by Apple would still incorrectly appear as owned by Intel. Companies like Huawei, LG, or Samsung, which have sold parts of their portfolios, would show inflated patent counts. Conversely, patents may be omitted if owner names are not normalized or subsidiaries are not recognized. We see this in the cases of Nokia, Interdigital, CICT, Qualcomm, or Lenovo.
By comparing the public ETSI data with the LexisNexis matched data and with each company’s internal records, the Cellular Verified initiative ensured the highest level of accuracy and reliability in 5G patent data, providing the industry with a trusted benchmark. This effort ensured the identification of all publicly declared patents. The result is a clean and unbiased database that produces accurate and impartial patent counting statistics. To avoid any misunderstanding, the Cellular verified initiative did not ask any of the ETSI declaring companies to make comments about the essentiality or validity of their declared patents. The following example demonstrates how raw ETSI data can lead to significantly different and inaccurate rankings underrepresenting the 5G patent portfolios of certain companies. Given the sheer volume of declared patents, achieving a perfect match rate is nearly impossible without external validation. To overcome this limitation, feedback from 30+ declaring companies was incorporated into the process.
Figure 4 illustrates the progress of matching and cleaning efforts. It shows how the average matching rate improved from t1 (initial matching efforts) to t7 (final application of matching processes). One significant cleaning step, e.g., included a thorough investigation of identifying and matching provisional and priority patent application numbers between the periods of t6 and t7. Rigorous cleaning substantially enhances data accuracy. A perfect match rate is nearly unattainable without direct input from declaring companies responsible for the declared patents. Figure 4 well illustrates that the Cellular Verified initiative successfully increased the matching accuracy to ultimately achieve 99.99% accuracy of all published patent documents. This initiative underscores the importance of collaboration and advanced data processing in producing reliable 5G patent data information. The Cellular Verified data ensures that all statics of 5G declared patent rankings 99.99% represent those patents declared at ETSI, independent from a company’s deceleration behavior.
Patent declaration databases provide critical insights into 4G and 5G patent ownership. They serve as a foundational resource for stakeholders involved in patent licensing negotiations, patent commercialization, and patent pool formation. To navigate these processes effectively, access to comprehensive data on declared patents, pooled assets, and standards contributions is essential. SEP portfolios are inherently dynamic, evolving alongside advancements in patenting activity and the progression of standards. Understanding and calculating market share for a specific standard, such as 4G or 5G, requires a detailed analysis based on several key factors:
By leveraging these data points, stakeholders can assess the value of patent portfolios available for licensing. And they can prepare for fair, reasonable, and non-discriminatory (FRAND) negotiations. This approach also enables benchmarking SEP licensing offers against comparable agreements.The mission of LexisNexis® Intellectual Property Solutions is to bring clarity to 4G and 5G patent ownership. We do this by delivering the most accurate and comprehensive cellular patent declaration data, verified through collaboration with over 30 declaring companies, as part of the Cellular Verified project. These partners have supported efforts to clean, deduplicate, and match all declaration sources, ensuring the highest data integrity and reliability.
Discover the true leaders in 5G innovation and the patent landscape for 2025 based on verified patent analysis.
