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September 8, 2005.

PCTEL, INC., Plaintiff,
AGERE SYSTEMS, INC., et al. Defendants.

The opinion of the court was delivered by: MARTIN JENKINS, District Judge



Before the Court are the parties' proposed constructions of disputed terms contained in three of PCTEL, Inc.'s ("PCTEL") patents. The patents-in-suit describe and claim technology used in modems.


  This case concerns the alleged infringement of U.S. Patent Number 4,841,561 (the "'561" patent) entitled "Operating Default Group Selectable Data Communication Equipment," U.S. Patent Number 5,931,950 (the "'950" patent) entitled "Wake-Up-On-Ring Power Conservation for Host Signal Processing Communication System," and U.S. Patent Number 6,493,780 (the "'780" patent) entitled "Wake-Up-On-Ring Power Conservation for Host Signal Processing Communication System." PCTEL alleges that Agere Systems, Inc. and Lucent Technologies, Inc. (collectively "Agere"), have infringed each of the three patents. PCTEL also alleges that U.S. Robotics Corporation ("USR") infringed the '561 patent. The issue before the Court is the construction of disputed terms contained in the patents.

  A modem allows one or more electronic devices to communicate over telephone lines. Electronic devices that employ modems include personal computers, notebook computers and specialized computers such as ATM machines and cable TV set-top boxes. Modems are used to transmit computer signals over telephone lines because telephone lines are designed for analog signals, not digital signals. Modems receive digital signals from a computer and "modulate" the computer signals so that the signals have electrical characteristics suitable for transport over the telephone network as analog signals. In the other direction, modems receive analog signals from a telephone line and "demodulate" analog signals into digital signals that a computer understands. Modem is a contraction of "modulation" and "demodulation."

  A. '561 patent

  The '561 patent claims a multi-country modem feature so that a single modem can be used in multiple countries. In the mid-1980's, different countries had different requirement for connecting to and communicating over their telephone lines. For example, some of the parameters that varied by country were: 1) the make/break ratio; 2) guard tone; 3) line impedance; and 4) transmit line signal level. The '561 patent included the parameters for desired countries and when a desired country is selected, the patented feature loads the proper parameters, properly configuring the modem for the selected country.

  Thus, the '561 patent permits portable computer users to use their modem in foreign countries. This multi-country support also allows desktop, server and specialized computer manufactures to sell throughout the world a computer with a modem, which may be sold and used in different countries.

  B. '950 and '780 patents

  The '950 and'780 patents describe and claim a host signal processing ("HSP") modem that permits a host computer to enter a power savings state, while retaining the ability for the HSP modem to receive an incoming telephone or modem call.

  As computers became faster and more powerful, they consumed correspondingly greater amounts of electricity. Computer manufactures developed techniques for reducing the power consumption of their products. To overcome this problem, the inventor of the '950 and '780 patents invented a modem that allows a power management system to place a computer in power-saving mode when there is no active connection, yet still allows the modem to respond to incoming calls. Thus, in sum, with the use of the claimed invention of the '950 and '780 patents, the host computer is capable of entering a sleep mode, and unlike prior HSP modem systems, still handle incoming calls.


  The construction of a patent claim is a matter of law for the Court. Markman v. Westview Instruments, Inc., 517 U.S. 370, 372 (1996). The Court must conduct an independent analysis of the disputed claim terms. It is insufficient for the Court to simply choose between the constructions proposed by the adversarial parties. Exxon Chem. Patents v. Lubrizol Corp., 64 F.3d 1553, 1555 (Fed. Cir. 1995). To determine the meaning of a patent claim, the Court considers three sources: the claims, the specification, and the prosecution history. Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc), aff'd, Markman, 517 U.S. 370.

  The Court looks first to the words of the claims. Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). "Although words in a claim are generally given their ordinary and customary meaning, a patentee may choose to be his own lexicographer and use terms in a manner other than their ordinary meaning, as long as the special definition of the term is clearly stated in the patent specification or file history." Id. (citation omitted). "A technical term used in a patent document is interpreted as having the meaning that it would be given by persons experienced in the field of the invention, unless it is apparent from the patent and the prosecution history that the inventor used the term with a different meaning." Hoechst Celanese Corp. v. BP Chems. Ltd., 78 F.3d 1575, 1578 (Fed. Cir. 1996). The doctrine of claim differentiation creates the presumption that limitations stated in dependent claims are not to be read into the independent claim from which they depend because different language used in separate claims is presumed to indicate that the claims have different meanings and scope. Tandon Corp. v. U.S. International Trade Com., 831 F.2d 1017, 1023 (Fed. Cir. 1987).

  Second, it is always necessary to review the specification to determine whether the inventor has used any terms in a manner inconsistent with their ordinary meaning. Vitronics, 90 F.3d at 1582. The specification can act as a dictionary when it expressly or impliedly defines terms used in the claims. Id. Because the specification must contain a description of the invention that is clear and complete enough to enable those of ordinary skill in the art to make and use it, the specification is the single best guide to the meaning of a disputed term. Id. The written description part of the specification itself does not delimit the right to exclude, however; that is the function and purpose of claims. Markman, 52 F.3d at 980.

  Third, the court may consider the prosecution history. Vitronics, 90 F.3d at 1582. "Although the prosecution history can and should be used to understand the language used in the claims, it too cannot enlarge, diminish, or vary the limitations in the claims." Markman, 52 F.3d at 980 (internal quotation marks deleted) (citations omitted). However, a concession made or position taken to establish patentability in view of prior art on which the examiner has relied, is a substantive position on the technology for which a patent is sought, and will generally generate an estoppel. In contrast, when claim changes or arguments are made in order to more particularly point out the applicant's invention, the purpose is to impart precision, not to overcome prior art. Such prosecution is not presumed to raise an estoppel, but is reviewed on its facts, with the guidance of precedent. Pall Corp. v. Micron Separations, Inc., 66 F.3d 1211, 1220 (Fed. Cir. 1995) (citations omitted).

  Ordinarily, the Court should not rely on expert testimony to assist in claim construction, because the public is entitled to rely on the public record of the patentee's claim (as contained in the patent claim, the specification, and the prosecution history) to ascertain the scope of the claimed invention. Vitronics, 90 F.3d at 1583. "[W]here the public record unambiguously describes the scope of the patented invention, reliance on any extrinsic evidence is improper." Id. Extrinsic evidence should be used only if needed to assist in determining the meaning or scope of technical terms in the claims, and may not be used to vary or contradict the terms of the claims. Id. (quoting Pall Corp., 66 F.3d at 1216); Markman, 52 F.3d at 981.

  The Court "is free to consult technical treatises and dictionaries at any time, however, in order to better understand the underlying technology and may also rely on dictionary definitions when construing claim terms, so long as the dictionary definition does not contradict any definition found in or ascertained by a reading of the patent documents." Vitronics, 90 F.3d at 1584 n. 6. The Court also has the discretion to admit and rely upon prior art proffered by one of the parties, whether or not cited in the specification or the file history, but only when the meaning of the disputed terms cannot be ascertained from a careful reading of the public record. Id. at 1584. Referring to prior art may make it unnecessary to rely on expert testimony, because prior art may be indicative of what all those skilled in the art generally believe a certain term means. Id. Unlike expert testimony, these sources are accessible to the public prior to litigation to aid in determining the scope of an invention. Id.

  Disputed claim terms are construed consistently across all claims within a patent. Southwall Techs., Inc. V. Cardinal IG Co., 54 F.3d 1570, 1579 (Fed. Cir. 1995). Where patents-in-suit share the same disclosures, common terms are construed consistently across all claims in both patents. Mycogen Plant Sci., Inc. v. Monsanto Co., 252 F.3d 1306, 1311 (Fed. Cir. 2001) (overruled on other grounds).

  "The subjective intent of the inventor when he used a particular term is of little or no probative weight in determining the scope of a claim (except as documented in the prosecution history)." Markman, 50 F.3d at 985 (citation omitted). "Rather the focus is on the objective test of what one of ordinary skill in the art at the time of the invention would have understood the term to mean." Id. at 986.


  The following is a list of eleven terms identified by the parties in the March 16, 2005 Revised Joint Claim Construction and Prehearing Statement:
1) memory means
2) hardware related [operating] parameter
3) changing a [the] hardware configuration
4) means for changing a [the] hardware configuration
5) to assume a proper configuration
6) host signal processing [communication system/modem]
  7) host processor 8) periodically asserts a first signal while operating in a first mode

  9) as the interrupt signal

  10) periodic interrupts

  11) selection logic


  I. The '561 Patent

  A. memory means (Claims 1, 2, 5, 10)

  A "means-plus-function" claim is a special type of claim provided for in 35 U.S.C. § 112, paragraph 6, which provides:
An element in a claim for a combination may be expressed as a means or a step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
35 U.S.C. § 112, ¶ 6. Under this provision, an inventor can describe an element of the invention by the result accomplished or the function served, rather than by describing the item or element to be used. Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co., 520 U.S. 17, 27 (1997). When using means-plus-function language, "[t]he applicant must describe in the patent specification some structure which performs the specified function." Valmont Industries, Inc. v. Reinke Manufacturing Co., Inc., 983 F.2d 1039, 1042 (Fed. Cir. 1993). A structure disclosed in the specification is only deemed to be "the corresponding structure" if the specification clearly links or associates that structure to the function recited in the claim. Kahn v. General Motors Corp., 135 F.3d 1472, 1476 (Fed. Cir. 1998). The duty to link or associate structure in the specification with the function is the quid pro quo for the convenience of employing the means-plus-function format. Id.

  An accused device with a structure that is not identical to the structure described in the patent will literally infringe the patent if the accused device performs the identical function required by the means-plus-function claim with a structure identical or equivalent to that described in the patent. Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1457 (Fed. Cir. 1998) (en banc); Kahn, 135 F.3d at 1476. "Thus, the statutory provision prevents an overly broad construction by requiring reference to the specification, and at the same time precludes an overly narrow construction that would restrict coverage solely to those means expressly disclosed in the specification." Symbol Technologies, Inc. v. Opticon, Inc., 935 F.2d 1569, 1575 (Fed. Cir. 1991) (citations omitted).

  The parties disagree whether "memory means" is governed by 35 U.S.C. § 112 ¶ 6. PCTEL contends that this claim is not governed by § 112, ¶ 6.*fn1 However, if the claim is subject to § 112, ¶ 6, PCTEL contends that the corresponding structure is "memory and equivalents thereof." Agere contends that this claim is a means-plus-function limitation that is governed by § 112, ¶ 6. Agere asserts that the corresponding structure is "external memory ROM/RAM 50 of modem 10." USR contends that this claim is governed by § 112, ¶ 6, and that the corresponding structure is "a memory and equivalents thereof."

  PCTEL relies upon Envirco Corp. v. Clestra Cleanroom, Inc., 209 F.3d 1360 (Fed. Cir. 2000), to support its proposition that the term is not governed by § 112, ¶ 6.*fn2 In Envirco, the Federal Circuit held that the word "baffle" alone constituted sufficient structure, and trumped the use of the word "means." Id. at 1364-65. "Because the term "baffle" itself imparts structure, meaning a surface which deflects air, its use in the claims rebuts the presumption that § 112, ¶ 6 applies." Id. at 1365.

  PCTEL also relies upon Katz v. AT&T Corp., 63 F. Supp. 2d 583, 640 (E.D. Pa. 1999), where the court held that "memory means" is not subject to analysis under § 112 ¶ 6 because the word "memory" connotes sufficient structure to rebut the presumption that the term is written in means-plus-function format. The Katz court construed "the term `memory' according to its plain meaning as: computer hardware that stores information, such as disks, RAM, or tapes." Id. at 602 n. 14.

  Agere and USR assert that this claim limitation is a means-plus-function limitation, and rely upon Genlyte Thomas Group LLC v. Lutron Elecs. Co., Inc., 2004 WL 690847, *11-13 (N.D. Tex. March 31, 2004). In Lutron, the court concluded that "`memory means' is means plus function language, and the Court must determine the structure described in the specification for carrying out the function of storing information. . . ." Id. at *11. Other courts have agreed with this conclusion. See British Telecomm. PLC v. Prodigy Comm. Corp., 189 F. Supp. 2d 101, 127-31 (S.D.N.Y. 2002); Lucent Techs., Inc. v. Newbridge Networks Corp., 168 F. Supp. 2d 181, 202 (D. Del. 2001).

  As in Lutron and Lucent, the Court finds that PCTEL has not overcome the presumption that "memory means" is a means-plus-function limitation. The function of this element is to store values for storing operating parameters. The structure associated with this element is memory associated with "External Memory ROM/RAM 50."

  However, the parties' disagree regarding the precise scope of the structures to be included in the claim. PCTEL and USR assert that the structure of "memory means" is "memory and equivalents thereof." PCTEL contends that the '561 patent discloses a discrete class of structures that perform the claimed function and admits that a specific, preferred type of memory is disclosed in embodiment of the patant (i.e., ROM and RAM). PCTEL argues that it should not be penalized for having disclosed a preferred type of memory by having the scope of the claims narrowed so as to only cover a certain type of memory. Along the same lines, PCTEL asserts that the location of its memory should not be limited to only "external" memory.

  Agere responds that the only disclosed embodiment of the invention of the '561 patent expressly discloses that the structure corresponding to the "memory means" is "External Memory ROM/RAM 50 of modem 10." Agere also notes that Fig. 1 of the '561 patent discloses that External Memory ROM/RAM 50 of modem 10 is separate and "external" to the data terminal equipment, which can contain a separate ROM and/or RAM of its own.

  At this stage of the litigation, the Court need only identify all corresponding structures disclosed in the specification of the '561 patent. "[T]he scope of such a claim is not limitless, but is confined to structures expressly disclosed in the specification and corresponding equivalents." Symbol Technologies, 935 F.2d at 1575. The Court notes that the specification reveals "memory means" such as "RAM," "ROM," "EPROM," and "EEPROM." Therefore, the Court finds that the structure corresponding to "memory means" is memory 50, including "RAM," "ROM," "EPROM," or "EEPROM." The Court declines to limit the location of the memory to only "external memory."

  B. Hardware Related [Operating] Parameter (Claims 1 and 11)

  PCTEL states that the term has a plain and understood meaning, and no construction of the term is necessary. Alternatively, PCTEL contends that the term should be construed as "characteristics relating to electrical/physical properties of circuitry." To support its ...

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