Addressing whether arguments made during prosecution serve to disavow the plain meaning of certain claim terms, the US Court of Appeals for the Federal Circuit reversed the district court’s claim construction, finding that there was no clear disavowal of claim scope. Intellectual Ventures I LLC v. T-Mobile USA, Inc.Case Nos. 17-2434, -2435 (Fed. Cir. Sept. 4, 2018) (Moore, J).

Intellectual Ventures owns a patent directed to “an application-aware resource allocator that allocates bandwidth resources to transmit information from software applications over a packet-switched network.” Specifically, the resource allocator is able to adjust the quality of service (QoS) to prioritize either speed or error minimization based on the application type. In order to determine the proper QoS, the patented technology takes into account the seven-layer Open Systems Interface (OSI) standard, which defines multiple network protocol “layers” between layer 1, the physical layer, and layer 7, the application layer.

After being sued, T-Mobile moved for summary judgment on the basis of non-infringement and indefiniteness under 35 USC § 112. T-Mobile argued that the term “allocate[] resources based on application type” requires allocating resources using information obtained in at least OSI layer 7, the application layer. T-Mobile based its construction on certain remarks made during the prosecution of the asserted patent, arguing that the remarks disavowed any additional claim scope. Conversely, Intellectual Ventures argued for a broader interpretation, indicating that the term may include information obtained from any of OSI layers 3, 4 or 7. The district court agreed with T-Mobile, noting that the construction was supported by the prosecution history. The district court also found that the term “QoS requirements” was indefinite. Intellectual Ventures appealed.

The Federal Circuit reversed the district court’s claim construction finding. The Court first analyzed the claims and specification, noting that Intellectual Ventures’ construction was most consistent with the plain meaning of the disputed terms. The Court next turned to patentee’s purported disavowal, finding that “[d]isavowal is an exacting standard under which it must be established that the patentee demonstrated an intent to deviate from the ordinary and accustomed meaning of a claim term through expressions of manifest exclusion or restriction, representing a clear disavowal of claim scope.” T-Mobile cited multiple instances within the prosecution history where patentee defined “application awareness [as] refer[ring] to knowledge above the TCP or UDP layer” (i.e., above layer 6). However, the Court concluded that patentee’s statements fell short of the “exacting standard” required for disavowal, and consequently found “no intent to deviate from the full scope of the claims.”

Turning to indefiniteness, the Federal Circuit affirmed the district court’s finding that the definition of “QoS requirements” within a means-plus-function claim was indefinite. The specification of the asserted patent defined QoS requirements as “a continuum, defined by what network performance characteristic is most important to a particular user [and which has] different meanings for different users.” The Court found this definition to be “purely subjective.” Thus, the claim was deemed indefinite without the need to evaluate any means-plus-function structure.

Practice Note: In finding the “QoS requirements” indefinite, the Federal Circuit explained that terms of degree that depend upon “the unpredictable vagaries of any one person’s opinion” are, by definition, purely subjective. Thus, drafters should use caution when combining terms of degree with user preferences.