By Thomas Long, J.D.
A district court’s ruling that T-Mobile and other mobile device makers did not infringe a patent describing a media access control layer that allocated bandwidth resources based on application type was the result of an erroneous claim construction, the U.S. Court of Appeals for the Federal Circuit has decided. Therefore, the district court’s grant of summary judgment in favor of the defendants was vacated, and the case was remanded. The appellate court affirmed, however, the district court’s determination that certain claim language about allocating resources to "optimize" the quality of service was indefinite because the quality of service requirements were entirely subjective and user-defined (Intellectual Ventures I LLC v. T-Mobile USA, Inc., September 4, 2018, Moore, K.).
Patent-in-suit. Owned by Intellectual Ventures I LLC ("IV), the patent-in-suit was U.S. Patent No. 6,640,248 ("the ’248 patent"). The ’248 patent described "an application-aware resource allocator" that allocated bandwidth resources to transmit information from software applications over a packet-switched network. According to the patent, quality of service (QoS) requirements may vary among applications, with some types of applications demanding error minimization and others prioritizing speed. To meet these varying requirements, the application-aware resource allocator "allocates bandwidth resource to an application based on an application type." Specifically, the application-aware resource allocator allocates resources to an Internet protocol (IP) flow of IP packets associated with the application.
The ’248 patent makes reference to the seven-layer Open Systems Interface networking protocol stack standard ("OSI standard"), which includes a "physical layer" at layer 1, a "data link layer" at layer 2, a "network layer" at layer 3, a "transport layer" at layer 4, and an "application layer" at layer 7. The claims at issue in this case were independent claims 1 and 20, which, respectively, described (1) an application aware, QoS sensitive media access control (MAC) layer and (2) an application-aware MAC layer for optimizing end user application IP QoS to IP flows.
Infringement suit. IV filed suit against T-Mobile USA, Inc., T-Mobile US, Inc., Ericsson Inc., Telefonaktiebolaget LM Ericsson, and United States Cellular Corporation (collectively, "T-Mobile"). The federal district court in Wilmington, Delaware, granted T-Mobile’s motion for summary judgment of noninfringement. IV appealed to the Federal Circuit.
Construction—"application-aware resource allocator." The parties disputed the construction of "application-aware resource allocator" in claim 1 and "application-aware media access control (MAC) layer" in claim 20. The district court adopted T-Mobile’s proposed construction requiring that the resource allocator not only "ha[ve] knowledge of the type of data application," but that it "further take into account, when allocating bandwidth, information about applications at [OSI] application layer 7." The district court noted this construction was "supported by the prosecution history, during which the patentee distinguished its invention from prior art based on the fact that the invention is ‘aware of layer 7 application information’ and, further, that the resource allocator must ‘be able to take into account, when allocating bandwidth, information at … layer 7.’"
IV argued that the district court’s construction was erroneous because application awareness required only that the resource allocator allocate resources based on application type, which can be discerned using information obtained from any of network layer 3, transport layer 4, or application layer 7. The Federal Circuit agreed. The plain language of the claims, the specification, and the prosecution history all supported IV’s construction. The claim language did not specify how the resource allocator becomes "aware" of an application. Nothing required that the application type be identified using information obtained from application layer 7. The specification contemplated determining the "IP QoS requirements of said software application" in claim 1 and the "application type" in claim 20 using information obtained from any of network layer 3, transport layer 4, or application layer 7. In the court’s view, statements made by IV during prosecution did not amount to a clear disavowal of claim scope. References to applications running at application layer 7 were not intended to restrict the claim scope to layer 7, and other statements by IV made it clear that the resource allocator could use information from network layer 3 and transport layer 4.
Because the district court’s grant of summary judgment of noninfringement was the result of an erroneous claim construction, the appellate court vacated and remanded.
Indefiniteness—"allocating means for allocating resources to said IP flow." IV also argued that the district court erred in determining that the language in claim 20, "allocating means for allocating resources to said IP flow … so as to optimize end user application IP QoS requirements of said software application," was indefinite. According to IV, the specification provided sufficient structure to render the "allocating means" definite, but the district court erroneously failed to consider this structure after determining the function was indefinite. The Federal Circuit disagreed. According to the court, the "QoS requirements" were entirely subjective and user-defined. QoS was analogous to "a continuum, defined by what network performance characteristic is most important to a particular user." The specification characterized it as "a relative term, finding different meanings for different users." The patent stated that "Ultimately, the end-user experience is the final arbiter of QoS." Therefore, "optimizing" QoS depended on a user’s subjective opinion, which was unpredictable, and the claim language did not inform a skilled person with any way to determine whether QoS had been optimized. Because the function was indefinite, there was no need to evaluate the claimed structure, the court said. The Federal Circuit therefore affirmed the district court’s determination that the "allocating means" in claim 20 were indefinite.
Attorneys: Martin Jay Black (Dechert LLP) for Intellectual Ventures I LLC. Douglas M. Kubehl (Baker Botts, LLP) for T-Mobile USA, Inc., T-Mobile US, Inc., Ericsson Inc. and U.S. Cellular Corp.
Companies: Intellectual Ventures I LLC; T-Mobile USA, Inc.; T-Mobile US, Inc.; Ericsson Inc.; U.S. Cellular Corp.
MainStory: TopStory Patent FedCirNews
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