DCT

6:06-cv-00550

Commonwealth Scientific Industrial Research Organisation v. Toshiba America Information Systems Inc

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I. Executive Summary and Procedural Information

Case Timeline

Date Event
1992-11-27 U.S. Patent No. 5,487,069 Priority Date
1996-01-23 U.S. Patent No. 5,487,069 Issued
2007-06-21 Complaint Filing Date
2011-03-15 First Reexamination Certificate (US 5,487,069 C1) Issued
2012-07-03 Second Reexamination Certificate (US 5,487,069 C2) Issued

II. Technology and Patent(s)-in-Suit Analysis

  • Patent Identification: U.S. Patent No. 5,487,069, "Wireless LAN," issued January 23, 1996 (the “'069 Patent”).

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of achieving high-speed wireless data transmission in indoor environments like offices (’069 Patent, col. 1:4-11). At high frequencies, radio signals reflect off walls and furniture, creating multiple signal paths ("multipath") to the receiver. These delayed reflections can interfere with subsequent data signals, causing errors and severely limiting the data rate (’069 Patent, col. 3:41-4:6).
  • The Patented Solution: The invention proposes a method to combat multipath interference by modulating data onto a plurality of parallel, lower-data-rate "sub-channels" (’069 Patent, col. 2:50-61). The key insight is to make the transmission time (the "period") of a data symbol on each sub-channel longer than the time delay caused by the significant multipath reflections. This ensures that echoes from one symbol do not corrupt the next, enabling reliable high-speed communication overall (’069 Patent, col. 2:38-48). The patent describes implementing this using techniques, such as an Inverse Fast Fourier Transform (IFFT) modulator, that are characteristic of Orthogonal Frequency-Division Multiplexing (OFDM) (’069 Patent, Fig. 7).
  • Technical Importance: This approach provided a viable solution to the multipath problem that did not rely on bulky directional antennas or computationally intensive equalizers, paving the way for the widespread commercial adoption of high-speed WLANs (’069 Patent, col. 1:46-57).

Key Claims at a Glance

  • The complaint does not specify which claims are asserted. The analysis below focuses on independent claim 10 as a representative claim that was confirmed during reexamination.
  • Independent Claim 10 includes the following essential elements:
    • A wireless LAN comprising a plurality of hub transceivers and a plurality of mobile transceivers.
    • Each mobile transceiver is operable to transmit and receive data at radio frequencies in excess of 10 GHz in a confined multipath environment.
    • Each mobile transceiver includes a modulation means for modulating input data into a plurality of sub-channels.
    • The sub-channels are comprised of a sequence of data symbols where the period of a sub-channel symbol is longer than a predetermined period representative of the time delay of significant non-direct transmission paths.
    • The mobile transceiver includes means to apply a data reliability enhancement to the data passed to the modulation means.
    • The mobile transceiver includes means for interleaving blocks of said data, interposed between the reliability enhancement means and the modulation means.

III. The Accused Instrumentality

Product Identification

  • The complaint does not identify specific accused products by name. Instead, it accuses broad categories of products manufactured, used, or sold by the Defendants that practice the IEEE 802.11a, 802.11g, and/or draft 802.11n standards (Compl. ¶¶14-22).

Functionality and Market Context

  • The accused instrumentalities are devices—such as laptops, routers, and gaming consoles—that incorporate Wi-Fi technology for wireless networking (Compl. ¶¶2-11). The complaint alleges that the functionality required by the 802.11a/g/n standards for wireless communication inherently practices the invention of the ’069 Patent (Compl. ¶¶14-22). These standards have been fundamental to the growth of the global wireless networking market.

IV. Analysis of Infringement Allegations

The complaint does not provide element-by-element infringement allegations or a claim chart. The infringement theory is articulated in broad terms, alleging that any product compliant with the specified 802.11 standards necessarily infringes the ’069 Patent (Compl. ¶¶14-22). A central part of the litigation would therefore involve determining whether the mandatory requirements of these standards map onto the limitations of the asserted claims.

No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Scope Questions: The primary dispute will likely be whether compliance with the accused IEEE standards requires infringement of every limitation of an asserted claim, such as claim 10. For example, do the standards' mandatory specifications for OFDM symbol timing, data reliability (e.g., Forward Error Correction), and interleaving fall within the scope of the corresponding claim limitations as construed by the court?
    • Technical Questions: A key technical question is whether the specific implementations of OFDM in the 802.11 standards meet the claim limitation requiring the sub-channel symbol period to be "longer than a predetermined period representative of the time delay of significant ones of non-direct transmission paths." This may involve factual disputes over what constitutes a "significant" delay path in typical operating environments and how the standards address it.

V. Key Claim Terms for Construction

  • The Term: "the period of a sub-channel symbol is longer than a predetermined period representative of the time delay of significant ones of non-direct transmission paths" (from claim 10)

    • Context and Importance: This limitation is the core of the asserted invention for overcoming multipath interference. Its construction will define the required relationship between symbol duration and multipath delay, which will be central to determining whether the 802.11 standards infringe.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The "Objects and Summary" section describes the invention in functional terms, suggesting the period need only be sufficiently long to solve the problem, without being tied to a specific numerical value (’069 Patent, col. 2:38-48).
      • Evidence for a Narrower Interpretation: The specification provides a specific numerical example: "typical time delays... are of the order of 50 ns... the symbol time is of the order of 120 ns which is greater than the delay time" (’069 Patent, col. 8:39-50). A party could argue this example limits the scope of "longer than" to a relationship of similar magnitude.

  • The Term: "means to apply a data reliability enhancement" (from claim 10)

    • Context and Importance: This term, added to distinguish over prior art, is critical for infringement. The parties will dispute what specific techniques (e.g., Forward Error Correction, Automatic Repeat Request) are encompassed by this term and whether the methods used in the 802.11 standards are equivalent. Practitioners may focus on this term because it is not written in standard means-plus-function format, but its interpretation may still be influenced by the structures disclosed in the specification.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification lists several distinct techniques, including "automatic repeat request (ARQ)" and "forward error correction (FEC)" (’069 Patent, col. 8:31-34), suggesting the term is not limited to a single method.
      • Evidence for a Narrower Interpretation: The detailed embodiment focuses on "rate 1/2 TCM (trellis coded modulation) Encoder 42" and a "CRC... Checker 69," which implements an error check for re-transmission requests (’069 Patent, Fig. 7, Fig. 8). A party might argue these specific structures define the scope of the "means."

  • The Term: "means... for interleaving blocks of said data" (from claim 10)

    • Context and Importance: Interleaving is a standard technique in digital communications, so the patentability and infringement analysis will depend on the specific scope of this term. The dispute will center on whether the generic interleaving methods in the 802.11 standards are covered by the patent's claims.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes interleaving functionally as a technique that "improves the performance" of FEC schemes "by distributing the encoded data between the carriers" (’069 Patent, col. 7:16-24).
      • Evidence for a Narrower Interpretation: The patent provides a specific example of an interleaving scheme for a 12-carrier system: "Carrier number (1-12) modulated by successive encoder output di-bits: 1, 3, 5, 7, 9, 11, 2, 4, 6, 8, 10, 12, 1, 3, . . . etc." (’069 Patent, col. 10:26-34). A party could argue that this specific embodiment or its principle limits the scope of the term.

VI. Other Allegations

  • Indirect Infringement: The complaint makes conclusory allegations of indirect infringement against all Defendants (Compl. ¶¶14-22). It does not, however, plead specific facts to support the knowledge and intent required for induced infringement or to establish the elements of contributory infringement.
  • Willful Infringement: The complaint alleges that Defendants "have knowledge of their infringement" and that the infringement is "willful and deliberate" (Compl. ¶24). The complaint does not specify the basis for this alleged knowledge (e.g., pre-suit notification letters).

VII. Analyst’s Conclusion: Key Questions for the Case

  1. Standards-Essentiality and Claim Scope: A dispositive issue will be whether mandatory compliance with the IEEE 802.11a/g/n standards constitutes infringement of the asserted claims of the ’069 Patent as they were confirmed or amended in reexamination. This requires a two-step analysis: first, construing the scope of key claim limitations, such as the required relationship between symbol period and multipath delay, and second, comparing those construed claims to the technical requirements of the standards.

  2. Scope of "Enhancement" and "Interleaving" Means: The case may also turn on the interpretation of the "data reliability enhancement" and "interleaving" means in claim 10. A key question for the court will be whether these terms are construed broadly to cover the general techniques found in the 802.11 standards, or more narrowly to the specific embodiments disclosed in the patent, potentially allowing Defendants to design around or argue non-infringement.