IP Law Daily, PATENT—Fed. Cir.: Claims of Vivato patent for wireless communication system held invalid as indefinite, (May 18, 2023)

By Robert Margolis, J.D.

District court correctly construed term at issue as a means-plus-function term, and specification did not provide adequate corresponding structure to perform the claimed function.

The Court of Appeals for the Federal Circuit in Washington, D.C., has affirmed the decisions of two California district courts holding that an XR Communications, LLC, dba Vivato Technologies (“Vivato”) patent related to wireless communications systems is invalid as indefinite. The appellate court affirmed the holding by the Northern District of California that the term “search receiver logic” is a “means-plus-function” term, such that Vivato’s failure in the patent’s specification to disclose an adequate corresponding structure to perform the claimed function of the patent, rendered it indefinite and thus invalid. Because the same arguments were at issue in a case before the Central District of California, that court had reached the same conclusions about the indefiniteness of the patent’s claims, based on the collateral estoppel effect of the Northern District’s decision. The appellate court summarily affirmed that order as well (XR Communications, LLC dba Vivato Technologies v. Arris Solutions, Inc., May 18, 2023, Prost, S.) and (XR Communications, LLC dba Vivato Technologies v. D-Link Systems, Inc., May 18, 2023, per curiam).

Vivato owns U.S. Patent No. 6,611,231 (the “’231 patent”), relating to wireless communications systems. In two separate lawsuits, several claims of the ’231 patent were challenged as being invalid as indefinite. The Northern District of California, in the Arris Solutions case, construed a claim term in the ’231 patent as being subject to 35 U.S.C. § 112 ¶ 6 because it is a “means-plus-function” term, and with that statute providing the relevant legal framework, found the claims at issue to be invalid as indefinite. Subsequently, in the D-Link Systems case, the Central District of California reached the same conclusion as to the claims being invalid as indefinite, relying on the collateral-estoppel effect of the judgment in the Arris Solutions case. Vivato appealed the decisions in both cases. The Federal Circuit reviewed the decision in the Arris Solutions case and affirmed. Because there was no dispute that the appellate court’s affirmance of that decision compels affirming the decision in the D-Link Systems case, that decision was affirmed as well. The following discussion thus focuses on the district court and appellate court decisions in the Arris Solutions case.

Means-plus-function. The key term in the ’231 patent’s claims that the district court construed was “search receiver logic.” The first step in the district court’s analysis was to ask whether “search receiver logic” is a “means-plus-function term” that is subject to § 112 ¶ 6. If it is such a term, then the next step in the analysis would be to determine whether the ’231 patent’s specification discloses adequate surrounding structure so as not to render the claims indefinite under § 112 ¶ 2. The district court answered the first question by finding that “search receiver logic” does invoke § 112 ¶ 6. The appellate court agreed with that conclusion.

Whether a claim term invokes § 112 ¶ 6 is determined by looking at whether the term is drafted in a “means-plus-function” format. When the term to be construed does not include the word “means,” there is a rebuttable presumption that the term is not drafted in means-plus-function format. That presumption may be rebutted by evidence that the claim term does not “recite sufficiently definite structure” or otherwise recites a “function without reciting sufficient structure for performing that function.” Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1348 (Fed. Cir. 2015). The understanding of a person of ordinary skill in the art (“POSITA”) is the centerpiece of that determination.

In the district court, Vivato had agreed that one of the functions of “search receiver logic” is to “update said routing information.” The appellate court thus found that the question as posited by the district court—whether a POSITA would understand “search receiver logic” not just as structure, but as sufficient structure for performing the function that Vivato claimed, updating routing information—was the correct question to ask under the above-quoted Williamson standard. The district court concluded, based on review of the ’231 patent’s specification and the competing expert declarations that a POSITA would not understand “search receiver logic” as structure for updating routing information, and as a result, the term invokes § 112 ¶ 6.

The appellate court held not only that the district court asked the correct question, but that it answered it correctly as well. The appellate court rejected Vivato’s argument that § 112 ¶ 6 is avoided where a term recites something a POSITA would understand as structure, even where a POSITA would not understand it as sufficient structure to perform the claimed function. Such a conclusion is inconsistent with Federal Circuit precedent, including Williamson, the appellate court held.

Adequate corresponding structure. Having determined that “search receiver logic” invokes § 112 ¶ 6, the appellate court moved on to the second step of the analysis: what structure disclosed in the specification, if any, corresponds to the claimed function of updating routing information? For this, the court must determine if intrinsic evidence clearly links the structure to the claimed function. In addition, the linked structure must be “adequate” to perform the claimed function. If the specification does not disclose a corresponding structure that is adequate to perform the claimed function, the claim is indefinite. The district court found a lack of adequate corresponding structure, and the appellate court again agreed.

Vivato had pointed to certain figures and steps set forth in its specifications, but the district court reviewed what Vivato had cited and concluded that none satisfied the “adequate corresponding structure” standard. Some did not disclose structure at all, and those that could be interpreted to do so depicted a process involving a function different than updating routing information. The appellate court found the district court’s analysis to be well-supported. Thus, the failure to meet the “adequate corresponding structure” standard rendered the claims at issue indefinite under § 112 ¶ 2 as the district court had found, the appellate court held.

The cases are Nos. 22-1125 and 2022-1141 (Arris Solutions) and 2022-1785, 2022-1787, 2022-1789, 2022-1790, 2022-1791, 2022-1792 (D-Link Systems).

Attorneys: Reza Mirzaie and Marc A. Fenster (Russ August & Kabat) for XR Communications, LLC, d/b/a Vivato Technologies. Matthew Yungwirth (Duane Morris LLP) for Arris Solutions, Inc. Jonathan K. Waldrop (Kasowitz Benson Torres LLP) for ASUS Computer International, Asustek Computer, Inc. Sarah E. Piepmeier (Perkins Coie LLP) for Cisco Systems, Inc. Daniel W. Richards (Ropes & Gray LLP) for Extreme Networks, Inc.

Companies: XR Communications, LLC, d/b/a Vivato Technologies; Arris Solutions, Inc.; ASUS Computer International, Asustek Computer, Inc.; Cisco Systems, Inc.; Extreme Networks, Inc.

Cases: Patent FedCirNews