Xiaomi to face off with Datang over 4G/5G SEP infringement in Munich in March 2026, successfully invalidates ASC patents in China

Context:

• In June, Datang (a subsidiary of the state-owned China Academy of Telecommunications Technology) sued Xiaomi in the Landgericht München I (Munich I Regional Court) over three 4G/5G standard-essential patents (case nos. 21 O 3009/25, 21 O 3216/25, and 21 O 7258/25: June 12, 2025 ip fray article).
• In November 2024, non-practicing entity (NPE) Advanced Standard Communication LLC (ASC) sued Xiaomi in the Unified Patent Court’s (UPC’s) Munich Local Division (LD) over EP3016464 (“Method for measuring discovery signal, base station, and terminal”) (November 28, 2024 ip fray article). Those allegations were then thrown out by the UPC in October, after
• they had to bring a new case over 5G and the old one remained limited to 4G.
• (October 30, 2025 ip fray article). In the meantime, Xiaomi filed a counterclaim for revocation against ASC over the asserted patent in the same court in May (UPC_CFI_398/2025).

What’s new: The Munich I Regional Court has scheduled the first hearing for Datang’s suit against Xiaomi for March 11, 2026 (case no. 21 O 3009/25: EP2237607 (“Method and apparatuses for implementing cell handover”)). Meanwhile, Xiaomi has successfully achieved the invalidation of three ASC patents (in three separate decisions issued by the China National Intellectual Property Administration’s (CNIPA’s) Patent Re-examination Board between November 13 and December 1, 2025 (below the box)).

Direct impact: While Xiaomi has gained a significant victory in China (as well as in the UPC in October), ASC has now filed fresh patent infringement allegations against Xiaomi over the same patent in the same court (UPC_CFI_0001321/2025) – this time, presumably focused on 5G claims (as the previous one was a 4G suit in which ASC had raised 5G infringement allegations too late).

Wider ramifications: The outcome of the Datang case in Munich will be particularly interesting as following a major shake-up announced by the UPC in October, Munich I Regional Court judge Dr. Georg Werner will be moving to the UPC’s Munich LD as of January 1, 2026 – meaning a new Presiding Judge will be overseeing that case (October 10, 2025 ip fray article).