DCT

6:20-cv-00142

UNM Rainforest Innovations v. ASUSTeK Computer Inc

Log In

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 6:20-cv-00142, W.D. Tex., 04/29/2021
  • Venue Allegations: Venue is asserted on the basis that Defendant is a foreign corporation, making venue proper in any U.S. judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s products implementing IEEE 802.11ac and 802.11ax Wi-Fi standards infringe three patents related to efficient wireless data transmission, including channel feedback, frame structuring, and bit allocation.
  • Technical Context: The patents address methods for improving the performance of multi-input, multi-output (MIMO) communication systems, which are foundational to modern high-speed wireless networking standards.
  • Key Procedural History: The patents-in-suit were originally assigned to the Industrial Technology Research Institute (ITRI), then conveyed to Sino Matrix Technology, Inc., and ultimately to Plaintiff UNM Rainforest Innovations. The complaint asserts sovereign immunity and states this filing does not waive it for inter partes review (IPR) proceedings. Subsequent to the filing of this complaint, IPR proceedings resulted in the cancellation of all asserted claims of the ’204 Patent and the ’326 Patent. For the ’326 Patent, new substitute claims were added, which are not asserted in the current complaint.

Case Timeline

Date Event
2007-07-12 ’096 Patent Priority Date
2008-07-08 ’326 Patent Priority Date
2008-07-11 ’204 Patent Priority Date
2012-08-21 ’204 Patent Issue Date
2012-09-11 ’096 Patent Issue Date
2013-10-22 ’326 Patent Issue Date
2021-04-29 Complaint Filing Date

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

U.S. Patent No. 8,249,204 - “Apparatus and method for channel state information feedback”

The Invention Explained

  • Problem Addressed: In complex Multi-Input Multi-Output (MIMO) wireless systems, a base station needs information about the quality of the communication channels—known as Channel State Information (CSI)—to optimize performance. Transmitting this CSI from a mobile device back to the base station consumes valuable bandwidth and resources. (’204 Patent, col. 1:32-47).
  • The Patented Solution: The patent proposes a method for the mobile station to efficiently report CSI. The mobile station first estimates the channel quality by calculating a "channel response," which includes a series of measurements called "channel taps." Instead of sending all the raw data, the mobile station compresses this information. The specification describes compression techniques such as selecting only the most significant channel taps and then generating a small set of mathematical parameters (using methods like least squares fitting) that can be used by the base station to reconstruct an approximation of the full channel response. (’204 Patent, Abstract; col. 4:53-58).
  • Technical Importance: Efficient CSI feedback enables advanced MIMO features like beamforming and resource allocation, which are essential for achieving the higher data rates and reliability promised by modern wireless standards. (’204 Patent, col. 1:36-43).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 11 and 12. (Compl. ¶40).
  • Independent Claim 1 requires:
    • A method for a mobile station to provide feedback of channel state information (CSI).
    • Estimating the CSI by calculating channel responses for multiple communication channels.
    • Selecting a plurality of "channel taps" from each calculated channel response.
    • Compressing the estimated CSI.
    • Sending the compressed CSI as feedback to the base station.
  • Note: As noted in Section I, all asserted claims of the ’204 Patent were later cancelled in an IPR proceeding.

U.S. Patent No. 8,265,096 - “Method for Constructing Frame Structures”

The Invention Explained

  • Problem Addressed: As wireless standards evolve, there is a need to ensure that new, more advanced systems (e.g., "new system") can coexist with older, widely deployed ones (e.g., "legacy system") while maintaining backward compatibility. A particular challenge is designing a data transmission frame that can accommodate the features and requirements of both. (’096 Patent, col. 1:30-34).
  • The Patented Solution: The invention discloses a method of constructing a single, unified data frame that contains distinct sections for different communication systems. The frame includes a first section with data formatted for a "first communication system" and a second section with data for a "second communication system." The second system can support features like higher mobility by using, for example, a shorter symbol period. The frame also includes non-data sections (such as a map) that tell receiving devices how the different zones within the frame are structured. (’096 Patent, Abstract; col. 4:40-54).
  • Technical Importance: This method provides a pathway for deploying next-generation wireless technologies without rendering the existing infrastructure and user devices immediately obsolete, a crucial consideration for any large-scale technology migration. (’096 Patent, col. 1:32-34).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 3, 4, 6, and 8. (Compl. ¶46).
  • Independent Claim 1 requires:
    • A method of constructing a frame structure for data transmission.
    • Generating a first section with data in a first format for a "first communication system."
    • Generating a second section with data in a second format for a "second communication system," where the second system supports higher mobility and uses a shorter symbol period than the first.
    • Ensuring the symbols for both systems can co-exist in one transmission scheme.
    • Generating at least one "non-data section" containing descriptive information about the data sections.
    • Combining these sections to form the final frame structure.
  • The complaint reserves the right to assert other claims.

U.S. Patent No. 8,565,326 - “System and Method for Bit Allocation and Interleaving”

  • Technology Synopsis: The patent addresses improving reliability in systems that retransmit data upon failure (a process known as HARQ). It describes a method where encoded data bits are first sorted into groups based on their importance ("significant" vs. "non-significant") and then allocated to sub-groups based on transmission reliability (e.g., "strong," "weak"). For a retransmission, the bits are rearranged between these groups and a circular shift is applied to change their sequence, increasing the probability of successful decoding. (’326 Patent, Abstract; col.2:9-24).
  • Asserted Claims: The complaint asserts independent claims 1 (method) and 5 (transmitter), as well as dependent claims 2 and 4. (Compl. ¶52).
  • Accused Features: The complaint alleges that the "transmitter and data transmission method" used in the accused products, which employ bit allocation and interleaving, infringes the patent. (Compl. ¶¶51, 53).
  • Note: As noted in Section I, all asserted claims of the ’326 Patent were later cancelled in an IPR proceeding and replaced with new substitute claims not asserted in this complaint.

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are a broad category of ASUS products, including computers, mobile phones, communications equipment, and networking devices (e.g., extenders, adapters, mesh systems) that are configured to operate on or with the IEEE 802.11ac and/or IEEE 802.11ax wireless networking standards. (Compl. ¶¶37-38).

Functionality and Market Context

  • The complaint alleges that these products, by implementing the 802.11ac/ax standards, necessarily perform the patented methods. This includes estimating and compressing CSI for feedback (’204 Patent), constructing data frames that combine legacy and new high-throughput formats (’096 Patent), and employing specific bit allocation and interleaving methods for reliable data transmission (’326 Patent). (Compl. ¶¶39, 45, 51).
  • The complaint does not provide specific details on the market positioning of the accused products but alleges they are made, used, sold, and imported in the Western District of Texas. (Compl. ¶13).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’204 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for a mobile station to provide to a base station feedback of channel state information (CSI)... Defendant's Accused Instrumentalities comprise mobile stations that communicate with base stations. Channel state information or “CSI” can be provided from a mobile station to base station. ¶39 col. 3:5-9
estimating the CSI by calculating a plurality of channel responses each for one of the communication channels; The mobile station is configured to estimate CSI by calculating responses for each communication channel... ¶39 col. 3:25-30
compressing the estimated CSI; It can also compress the estimated CSI... ¶39 col. 4:15-18
and sending the compressed CSI as the feedback to the base station, ...and send it as feedback to the base station. ¶39 col. 3:6-9
wherein the estimating further comprises selecting a plurality of channel taps from each of the calculated channel responses to estimate the CSI. ...and selecting channel taps from each calculated channel response. ¶39 col. 4:7-11
  • Identified Points of Contention:
    • Technical Questions: A primary question will be evidentiary: do the specific CSI feedback and compression mechanisms defined in the 802.11ac/ax standards meet the limitations of the claims? The complaint alleges the functions are performed but does not detail how. The defense may argue that the standards-based implementation is technically distinct from the specific least-squares or DCT-based compression embodiments described in the ’204 Patent specification.
    • Scope Questions: The case may raise the question of whether the term "compressing," in the context of the patent, is limited to the specific parametric modeling techniques disclosed, or if it can be read more broadly to cover any method of reducing CSI feedback overhead used in the accused standards.

’096 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of constructing a frame structure for data transmission, the method comprising: Defendant's Accused Instrumentalities... employ the patented frame structure for data transmission... ¶45 col. 8:1-2
generating a first section comprising data configured in a first format compatible with a first communication system using symbols; ...in which legacy communication format and very high throughput communication format are combined into a unitary frame structure. The legacy format corresponds to the "first communication system." ¶45 col. 4:43-47
generating a second section following the first section, the second section comprising data configured in a second format compatible with a second communication system using symbols, wherein the first... and the second communication system's symbols co-exist... The very high throughput (VHT) format corresponds to the "second communication system," which is combined with the legacy format in a single frame. ¶45 col. 4:47-54
wherein: the second format is compatible with the second communication system configured to support higher mobility than the first communication system, wherein each symbol... has a shorter symbol period... The complaint's allegation that the accused products practice claim 1 implies they meet this limitation, though it is not explicitly detailed. ¶46 col. 5:7-15
generating at least one non-data section containing information describing an aspect of data in at least one of the first section and the second section; The allegation that the accused products employ the frame structure implies the generation of necessary non-data fields (e.g., MAPs) required for decoding, as is standard in 802.11 frames. ¶45 col. 4:45-47
and combining the first section, the second section and the at least one non-data section to form the frame structure. ...legacy communication format and very high throughput communication format are combined into a unitary frame structure. ¶45 col. 2:27-30
  • Identified Points of Contention:
    • Scope Questions: A central dispute may be whether the patent’s terms "first communication system" and "second communication system," which are described in the context of the IEEE 802.16 (WiMAX) standard, can be construed to read on the legacy and VHT portions of the IEEE 802.11 (Wi-Fi) standard. The defense could argue these are distinct, non-analogous technology ecosystems.
    • Technical Questions: Does the 802.11ac/ax frame structure, which evolved from prior 802.11 versions, actually map onto the specific "first section" and "second section" architecture as claimed, or is the combination of formats implemented in a fundamentally different way?

V. Key Claim Terms for Construction

For the ’204 Patent

  • The Term: "compressing the estimated CSI"
  • Context and Importance: This term is at the heart of the invention. The infringement analysis will depend on whether the method of reducing CSI overhead in the accused 802.11ac/ax standards falls within the definition of "compressing" as used in the patent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language and abstract use the general term "compressing" without qualification, which a plaintiff might argue should cover any technique that reduces the amount of data in the CSI feedback. (’204 Patent, Abstract; col. 12:25-26).
    • Evidence for a Narrower Interpretation: The specification provides detailed examples of compression based on specific mathematical techniques: fitting sorted channel tap magnitudes to a line or curve using a least squares method, or applying a discrete cosine transform (DCT) to generate a small number of significant parameters. (’204 Patent, col. 4:53-58; col. 7:7-14). A defendant would likely argue the term should be limited to these disclosed embodiments.

For the ’096 Patent

  • The Term: "first communication system" / "second communication system"
  • Context and Importance: The claim requires a frame that combines these two systems. Practitioners may focus on this term because the patent's specification consistently uses the IEEE 802.16e (WiMAX) and 802.16m standards as examples. The viability of the infringement claim depends on whether these terms can be mapped to the 802.11 (Wi-Fi) context.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent frequently uses general descriptors like "legacy system," "new system," and "extended system," suggesting the invention is not tied to a single standard but to the general principle of evolving wireless systems. (’096 Patent, col. 1:30-34; col. 3:30-34).
    • Evidence for a Narrower Interpretation: The background and detailed description are rooted in the specific context and terminology of the IEEE 802.16 standards. A defendant may argue that the claimed "systems" and their corresponding frame structures are defined by this context and are technically distinct from the architecture of the 802.11 standards. (’096 Patent, col. 1:30-34; col. 3:40-42).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement for all three patents. The factual basis asserted is that Defendant designs its products to be used in an infringing manner and encourages such use by publishing manuals and promotional literature instructing on their operation. (Compl. ¶¶42, 48, 54).
  • Willful Infringement: For each patent, the complaint alleges that Defendant has had knowledge of its infringement since "it received notice." (Compl. ¶¶43, 48, 55). This suggests an allegation of post-suit willfulness, as no specific pre-suit knowledge is alleged. The prayer for relief requests treble damages. (Compl. ¶58.D).

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

  • A core issue will be one of standards-based interpretation: can the claims of the patents-in-suit, which were drafted with the architecture of the IEEE 802.16 (WiMAX) standards as a primary example, be construed to cover functionalities within the accused IEEE 802.11 (Wi-Fi) standards, or are the technical implementations and evolutionary paths of these standards too distinct?
  • A key evidentiary question will be one of technical proof: given the high-level allegations, what evidence will Plaintiff present to demonstrate that the accused 802.11ac/ax products perform the specific, and in some cases multi-step, technical methods required by the claim limitations, as opposed to functionally similar but technically distinct operations?
  • A critical threshold issue is the impact of the IPR proceedings: with all originally asserted claims of the ’204 and ’326 patents having been cancelled after the complaint was filed, the case against those patents as currently pled is effectively moot, raising the question of how or if Plaintiff will amend its case to proceed on the newly substituted claims of the ’326 patent.