The Software IP Report

The Federal Circuit on Claim Construction and Indefiniteness

In the recent case Intellectual Ventures I LLC v. T-Mobile USA, Inc., the Federal Circuit overturned a district court’s claim construction for reading in a limitation and upheld the district court’s invalidation for indefiniteness for including a subjective term.

Claim Construction

Intellectual Ventures is a patent assertion entity with an extensive portfolio, from agriculture and construction to nanotechnology and—relevant here—communications. This case began with IV suing wireless carrier T-Mobile in the District of Delaware, one of the busiest patent venues, for infringing U.S. Patent No. 6,640,248. The ’248 patent covers a way of allocating bandwidth for software applications to transmit over a packet-switched network, such as the internet. The claims are directed to a resource allocator that divvies out bandwidth according to which application is making the request. Here is claim 1:

1. An application aware, quality of service (QoS) sensitive, media access control (MAC) layer comprising:

an application-aware resource allocator at the MAC layer, wherein said resource allocator allocates bandwidth resource to an internet protocol (IP) flow associated with a software application of a user based on IP QoS requirements of said software application, wherein said resource allocator allocates said bandwidth resource in a packet centric manner that is not circuit-centric and does not use asynchronous transfer mode (ATM).

The parties disputed the construction of the italicized term “application-aware resource allocator.” IV’s construction required “allocating resources based on application type.” T-Mobile’s construction further required that the resource allocator “take into account, when allocating bandwidth, information about applications at application layer 7” of the Open Systems Interface networking protocol stack standard. In essence, the parties disagreed over whether the resource allocator had to use information from application layer 7 or could ignore application layer 7 in favor of network layer 3 or transport layer 4.

The district court had sided with T-Mobile based on statements made during prosecution history, but the Federal Circuit reversed. The court pointed first to the plain language of the claim, which does not mandate where the information comes from. Moreover, the specification lists information from the network layer 3 and the transport layer 4 that the resource allocator can use, and dependent claims do the same.

As for the district court’s reasoning, the Federal Circuit was unconvinced that the prosecution-history statements met the “exacting” standard for disavowing claim scope. The statements could mean merely that the resource allocator is aware of the applications at application layer 7, not that it is aware of the applications via information from application layer 7. The patentee therefore did not “demonstrate an intent to deviate from the ordinary and accustomed meaning of a claim term.” And so the court reversed the construction, and the case will continue at the district court


T-Mobile came out better on the second issue, indefiniteness. The term in question was means-plus-function language in claim 20:

20. An application-aware media access control (MAC) layer for optimizing end user application internet protocol (IP) quality of service (QoS) to IP flows comprising:

identifying means for identifying an application type of a software application associated with an IP flow; and

allocating means for allocating resources to said IP flow, responsive to said identifying means,so as to optimize end user application IP QoS requirements of said software application, wherein said resource allocating means allocates resources in a packet-centric manner that is not circuit-centric and does not use asynchronous transfer mode (ATM).

The test for indefiniteness is whether the claim “informs those skilled in the art about the scope of the invention with reasonable certainty.” The problem for IV is that the specification admits that “optimiz[ing] … QoS” is subjective, depending on what “is most important to a particular user,” “finding different meanings for different user.” Something that is a matter of opinion cannot provide “reasonable certainty.” Because of that, the Federal Circuit upheld the district court’s invalidation of claim 20.

Lessons for Practice

To show a disavowal, a defendant is often better served by focusing on the elements of the prior art rather than parsing the language of the patentee’s responses. (It’s not clear whether this strategy was available to T-Mobile here.) Heavy scrutiny of the language of the patentee’s counterarguments can often be outweighed by other intrinsic evidence. The prior art can support a more compelling story: the patentee shrank the scope of its claims because it hadto, in order to escape prior art disclosing the disavowed element.

And don’t put subjective language into your claims.