Last Month at the Federal Circuit
Last Month at the Federal Circuit

September 2012

Presumption Created by Doctrine of Claim Differentiation Not Overcome in Light of Patent Specification and Expert Testimony

Judges:  Newman (dissenting), Mayer, Bryson (author)
[Appealed from ITC]

In InterDigital Communications, LLC v. International Trade Commission, No. 10-1093 (Fed. Cir. Aug. 1, 2012), the Federal Circuit held that the ITC erred in construing certain critical claim terms in two patents, reversed the ITC’s finding of no infringement, and remanded the case to the ITC for further proceedings. 

InterDigital Communications, LLC and InterDigital Technology Corporation (collectively “InterDigital”) own U.S. Patent Nos. 7,190,966 (“the ’966 patent”) and 7,286,847 (“the ’847 patent”).  Both patents are directed to wireless cellular telephone technology and share a common specification.  The patents focus on apparatus and methods for controlling transmission power during the “handshake” portion of wireless cellular communication, during which a cell phone establishes contact with a cellular base station in order to initiate a call.  The claimed invention operates within a system that uses Code Division Multiple Access (“CDMA”) to allow multiple cell phones (referred to as “subscriber units”) within a certain geographical area to use the same portion of the radio frequency spectrum simultaneously.  The CDMA system is able to use a single portion of the frequency spectrum for multiple simultaneous communications by employing a process known as “spreading.”  A “spreading code” modifies the data signal so that the modified signal is transmitted at a faster rate and contains more information. 

InterDigital asked the ITC to investigate whether the ’966 and ’847 patents were infringed by Nokia Inc. and Nokia Corporation (collectively “Nokia”).  The ALJ construed the term “code” as limited to “spreading code.”  The ALJ found that the codes used in Nokia’s wireless communication initiation system are not spreading codes because they are not “used or intended to be used to increase the bandwidth of another signal,” and because those codes do not spread data or perform channelization and are not generated from a spreading code.  The ALJ also construed the term “increased power level” to mean that “the power level of a transmission is higher than that of a previous transmission.”  In light of the stated purpose of the invention, the ALJ added the requirement that “the power level of a code signal increases during transmission.”  Thus, the ALJ interpreted the claims to require that the power level of the signal be increased continuously throughout the ramp-up period in which transmissions are being sent from the subscriber unit, both during the intervals between transmissions and during the course of the individual transmissions themselves.  The ALJ found that Nokia’s products do not continuously increase the power level of the code signal during the ramp-up process.  For these reasons, the ALJ found no infringement, and the ITC affirmed. 

On appeal, the Federal Circuit explained that claim terms are usually given their ordinary meanings as understood by persons skilled in the art at the time of invention, and that two exceptions to the “plain meaning” rule arise where the patentee provides special definitions for claim terms, or when the patentee disavows the ordinary scope of a term during prosecution or explicitly in the specification.  The Court found neither exception present here.

“The administrative law judge’s construction of the term ‘code’ in claim 1 as meaning ‘spreading code’ renders claim 5 superfluous, a result that counsels strongly against that construction.”  Slip op. at 12.

The Court first addressed the claim term “code,” which it noted has an ordinary meaning of “a sequence of bits.”  The Court concluded that the ’966 and ’847 patent specifications do not provide any special limiting definition of “code,” and the prosecution history does not show any disavowal of the plain meaning of “code.” 

The Court agreed with the ALJ that the doctrine of claim differentiation applies because, if “code” means “spreading code,” as the ALJ ruled, claims 1 and 5 of the ’966 patent cover exactly the same subject matter.  The Federal Circuit disagreed with the ALJ, however, that the strong presumption created by the doctrine of claim differentiation against such a narrow construction had been overcome.  First, the Court explained that the fact that spreading codes are used in CDMA systems does not mean that every code used in a CDMA system must be a spreading code.  Second, the Court concluded that the ALJ used a different definition of “spreading code” than the patent specification or InterDigital’s expert witness and, under the ALJ’s construction, neither of the preferred embodiments in the common patent specification would fall within the scope of the claims.  The Court noted that experts for both InterDigital and Nokia confirmed that some of the codes described in the specification are examples of spreading codes, even though they do not spread or modulate data.

The Court found that this “disconnect” between the specification and the ALJ’s definition of “spreading code” led the ALJ to conclude both (1) that the patents were limited to spreading codes, based on the repeated references to spreading codes in the specification; and (2) that Nokia’s system did not use spreading codes, based on the fact that Nokia’s preamble codes do not spread data and are not generated from a spreading code.  Slip op. at 15-16.  Thus, the Court explained that the ALJ was in effect using different definitions of the term “spreading code” for purposes of claim construction and infringement, and, in order for the question of infringement to be appropriately determined, it is critical that the terms “code” and “spreading code” are assigned the same meaning both in the patents and in the analysis of the accused system.  The Court instructed the ITC to revisit this issue on remand.

Turning to the second claim construction issue, the meaning of the ’966 patent claim limitation “increased power level with respect to the prior transmission,” the Court noted that nothing in the specification or the claims clearly restricted the scope of the invention to the narrow interpretation adopted by the ALJ.  The ALJ restricted this claim term to require that the power level used to transmit the ramp-up signals be increased continuously, including during individual signal transmissions, rather than solely during the interim periods between individual transmissions.  Thus, the ALJ limited this term to continuous, not stepped or intermittent, power increases.  The Court, however, found no disclosure sufficient to indicate that the patentee intended to limit the invention in such a manner.  Indeed, the Court concluded that the plain language of the claims controls and held that InterDigital’s claims should be construed more broadly, covering continuous power increase and stepped increases between transmissions. 

The Court also addressed Nokia’s argument that InterDigital’s patent licensing activities alone did not satisfy the “domestic industry” requirement of section 337, 19 U.S.C. § 1337(a)(2) and (3).  The Federal Circuit agreed with the ALJ that § 337(a)(3) makes clear that the required U.S. industry can be based on patent licensing alone; it does not require that the articles that are the objects of the licensing activities (i.e., the “articles protected by the patent”) be made in this country.  Thus, the Court rejected Nokia’s arguments, reversed the ALJ’s determination of noninfringement, and remanded for further proceedings.

Judge Newman dissented.  In Judge Newman’s view, the dispositive issue is the scope of the claim term “code,” specifically whether it includes a scrambling code or is limited to the definition and usage of “code” in the specification.  Judge Newman found the meaning created for “code” by the panel majority “unsupported by and outside of the specification, where the majority’s definition is neither described nor enabled.”  Newman Dissent at 1.  Moreover, Judge Newman noted that “the doctrine of claim differentiation does not permit enlarging a claim term beyond its presentation in the specification.”  Id. at 2.  In other words, because “code” was described in the specification as only “spreading code,” the term could not be construed more broadly in the claim regardless of claim differentiation.  Thus, Judge Newman agreed with the ITC that the presumption of claim differentiation had been rebutted and that the codes referenced in the specification and claims are all spreading codes. 

Nokia has filed a petition for panel and en banc rehearing.