US patent infringement: Case presented by Finesse Wireless

A comprehensive expert report does not protect against defeat if the allocation of key claim features is not technically sound. In Finesse Wireless LLC v. AT&T Mobility LLC, No. 2024-1039, dated 24 September 2025, the Federal Circuit dismissed the infringement claims for both patents asserted and set aside the award of damages. The Supreme Court declined to hear the case on 29 June 2026; this refusal does not in itself constitute an endorsement of the substantive reasoning.

The technical error lay in the classification, not in a lack of specialist vocabulary

The case concerned the suppression of intermodulation interference in Nokia radio transmitters. In one patent, the expert assigned a signal to be sampled as claimed to a modelled signal path that was generated only after the sampling had taken place. This temporal and functional assignment did not support the allegation of infringement. In the case of the other patent, there was no adequate explanation of how the documented operations implemented the seven claimed multiplications.

This is particularly relevant for claims relating to software and signal processing: similar block names, identical objectives or mathematically related results do not constitute a robust assignment of the claimed processing steps. The infringement analysis should make it clear at what point a signal is present, when it is generated and what specific operation is performed on it.

For SEPs, it remains possible to prove infringement on the basis of standards

Finesse Wireless is not a FRAND decision and does not preclude the possibility of proving patent infringement on the basis of a standard. The relevant leading case remains Fujitsu Ltd. v. Netgear Inc., 620 F.3d 1321 (Fed. Cir. 2010). According to this, a standard may serve as evidence in relation to the product if its implementation necessarily leads to the realisation of the relevant patent features. In the case of optional standard components or different standard-compliant implementations, however, general standard compliance is not, as such, sufficient.

A standard claim chart should therefore not merely set out the wording of the claims alongside the relevant section of the standard. It should explain why the cited provision necessarily fulfils the feature. Terms such as „shall“, „may“ and implementation-dependent options may be more important for the line of reasoning than the length of the cited standard text.

Standard essentiality is not merely a question of how a claim is interpreted

In Godo Kaisha IP Bridge 1 v TCL Communication Technology Holdings Ltd., 967 F.3d 1380 (Fed. Cir. 2020), the Federal Circuit confirmed that the relevant questions of essentiality and compliance may be submitted to the jury in infringement proceedings. The patent holder was not required to have the issue of essentiality determined in advance as a pure point of law in the claim construction proceedings. The line of argument relied on the essentiality of mandatory standard components and the compliance of the accused devices with the standard.

When preparing for the proceedings, two separate chains of evidence should therefore be maintained: one linking the alleged infringement to the standard, and the other linking the standard to the product in question. Where the first chain leaves an option open, the second requires additional evidence of implementation.

It is advisable to use a table which, for each characteristic, sets out not only the relevant section of the standard but also its binding nature, the product allocation and the supporting evidence required for it. This makes it clear whether a characteristic actually derives from the standard or, unnoticed, contains a product-specific assumption.

The trial record must contain the key allocation

In the Finesse Wireless case, the lack of an explanation could not be remedied by a subsequently clarified classification in the appeal proceedings. The decisive factor was what had been presented to the jury as a sound basis for a finding of infringement.

On the defendant’s side, a Rule 50 application should therefore not merely state that the expert report is „conclusory“. It should identify the specific feature, the alleged classification and the decisive gap in the evidence. Rule 50 requires the specification of the decision sought, as well as the legal and factual grounds.

The practical implication is that a claim chart is procedurally sound if its key transitions can be explained and proven. In the context of SEP proceedings, this means in particular that compliance with the standard is a means of proving compliance, not a substitute for proving the features.

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