Statements Made During Patent Prosecution Held to Limit a Coined Term of Degree Despite No Clear Disavowal of Claim Scope by the Patentee

August 28th, 2019

SUMMARY:  Acknowledging a lack of clear disavowal of claim scope, the U.S. Court of Appeals for the Federal Circuit nevertheless recently upheld the U.S. District Court for the Eastern District of Texas’ claim construction limiting the scope of the phrase “high quality of service connection.” Iridescent Networks, Inc. v. AT&T Mobility, LLC, No. 2018-1449, 2019 U.S. App. LEXIS 23890, *16, 22 (Fed. Cir. Aug. 12, 2019).  Particularly, the Federal Circuit explained that a clear disavowal is unnecessary where the disputed phrase is a coined term of degree having no customary meaning in the art.  Finding the phrase “high quality of service connection” to be such a coined term of degree, the Federal Circuit concluded that the patentees’ statements made in response to an enablement rejection in the prosecution of a parent application and ascribing objective boundaries to the disputed phrase alone sufficed to limit the scope of the claim phrase. Id. at *10-13.

U.S. Patent No. 8,036,119 (the ‘119 Patent), assigned to Iridescent Networks, Inc. (“Iridescent”), is directed to improved methods for providing on demand guaranteed bandwidth to high bandwidth applications, such as video applications. Id. at *2-3.  Rather than using conventional ad hoc network routes for transmitting data packets, the claimed invention utilizes custom routes to “maximize the availability of the required bandwidth, minimize packet loss, and reduce latency.” Id. at *3.  The application that led to the ‘119 Patent was a continuation application of a parent application that eventually led to U.S. Patent No. 7,639,612 (the ‘612 Patent). Id. at *5.  The ‘119 Patent and the ‘612 Patent have substantially the same specification. Id.

During prosecution of the parent application, the independent claims containing the term “high quality and low latency bandwidth” were rejected for lack of enablement. Id.  In response, the rejected term was replaced with the term “high quality of service connection,” which the applicant argued was supported by Figure 3 and the accompanying description. Id. at *6.  Figure 3 (reproduced below) lists various applications and their respective minimum requirements for connection speed, packet loss, and latency.  Notably, the applicant described the term “high quality of service connection” as follows:

As illustrated by the boxed set of applications on the left side of the Fig. 3, high QoS (quality of service) may be viewed in the present application as having speeds varying from approximately 1-300 megabits per second, packet loss requirements that are typically about 10-5, and latency requirements that are typically less than one second.

Id. (citation omitted).  The examiner found the arguments persuasive and the application issued. Id.

Iridescent sued AT&T and Ericsson Inc. (collectively AT&T) for infringement of the ‘119 Patent. Id. at *7.  During claim construction, the district court construed “high quality of service connection” to mean “a connection that assures connection speed of at least approximately one megabit per second and, where applicable based on the type of application, packet loss requirements that are about 10-5 and latency requirements that are less than one second.” Id. (citation omitted).  The magistrate judge noted that the term “high quality of service connection” is “‘not a known term of art, but rather a term coined by the patentee.’” Id. at *7-8 (citation omitted). The magistrate judge explained that Iridescent’s statements made during prosecution and Figure 3 provide “‘some standard for measuring this term of degree.’” Id. at *8 (citation omitted).  The district court judge agreed with the magistrate judge’s construction, and as the parties agreed that AT&T’s accused network products and services were excluded under the court’s construction, the parties stipulated to noninfringment. Id.  The district court entered judgment in favor of AT&T and Iridescent appealed the decision to the Federal Circuit. Id.

At issue on appeal was whether the claimed term of degree “high quality of service connection” is “limited to the minimum connection parameter requirements disclosed in Figure 3 of the ‘119 Patent.” Id. at *10.  The Federal Circuit held that it is so limited. Id.

The meaning of a claim term “must be considered in the context of all the intrinsic evidence, including the claims, specification, and prosecution history.” Id. at *9 (quoting Biogen Idec, Inc. v. GlaxoSmithKline LLC, 713 F.3d 1090, 1094 (Fed. Cir. 2013)).  Moreover, “[s]tatements made during prosecution of a parent application are relevant to construing terms in a patent resulting from a continuation application if such statements relate to the subject matter of the claims being construed.” Id. at *9 (citations omitted).

In construing the claims, the Federal Circuit stated that the claim language was not sufficiently clear on its face to provide guidance to a person of skill in the art as to the meaning of the term “high quality of service connection,” and consequently, the Federal Circuit looked to the specification and the prosecution history for guidance. Id. at *10.  Upon reviewing the prosecution history, and specifically looking to the parent application, the Federal Circuit pointed out that the applicant of the ‘119 Patent relied on Figure 3 to support the amendment related to overcoming the enablement rejection. Id. at *10-11.  As noted above, the box labeled “High QoS” includes some of the applications—but not all. Id.  Thus, the Federal Circuit reasoned, Figure 3 and the accompanying description imply that a “‘high quality of service connection’ involves minimum service parameters required by the applications within the ‘High QoS’ box.” Id. at *11-12.  The Federal Circuit held that the minimum connection parameter requirements for “high quality” applications thus correlate with applications having connection “speeds varying from approximately 1-300 megabits per second, packet loss requirements that are typically about 10-5, and latency requirements that are typically less than one second . . . .” Id. at *12 (citation omitted).

To counter, Iridescent contended that “the prosecution history is irrelevant to the claim construction question because there is no clear and unmistakable disavowal of claim scope.” Id. at *16 (citation omitted).  Iridescent relied on 3M Innovative Properties Co. v. Tredegar Corp. for the proposition that “where there is no clear disavowal, ‘the ordinary and customary meaning of the claim term will be given its full effect.’” Id. at *16-17 (quoting 3M Innovative Properties Co. v. Tredegar Corp., 725 F.3d 1315, 1326 (Fed. Cir. 2013)).  The Federal Circuit explained that Iridescent’s reliance on 3M was misplaced because the “disputed term is a coined term” and thus does not have an “ordinary and customary meaning.” Id. at *17.  Accordingly, the Federal Circuit held that “where there is no clear ordinary and customary meaning of a coined term of degree, we may look to the prosecution history for guidance without having to first find a clear and unmistakable disavowal.” Id. at *17.

Iridescent also contended that its statements during prosecution were made in response to an enablement rejection and thus are “irrelevant to the construction of the disputed term.” Id.  The Federal Circuit addressed this contention by stating that “Iridescent’s statements made to overcome the examiner’s enablement rejection inform the claim construction analysis by demonstrating how Iridescent understood the scope of the disputed term.” Id. at *18.

Takeaway: Any explanation, elaboration, or qualification of a coined term of degree, having no ordinary and customary meaning in the art, presented by a patentee during patent prosecution can limit the scope of the coined term of degree—even despite no clear disavowal of scope by the patentee.