DCT
2:25-cv-01152
Integral Wireless Tech LLC v. D Link Corp
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Integral Wireless Technologies LLC (Texas)
- Defendant: D-Link Corporation (Taiwan)
- Plaintiff’s Counsel: Rozier Hardt McDonough, PLLC
- Case Identification: 2:25-cv-01152, E.D. Tex., 11/24/2025
- Venue Allegations: Venue is alleged to be proper because the defendant, D-Link, is a foreign corporation that does not reside in any U.S. judicial district.
- Core Dispute: Plaintiff alleges that Defendant’s extensive portfolio of Wi-Fi routers, access points, cameras, and other wireless networking products infringes eight patents related to various aspects of wireless communication and network functionality.
- Technical Context: The patents cover a wide range of technologies foundational to modern wireless networking, including MIMO-OFDM communication, Bluetooth and Wi-Fi coexistence, power-saving "wake-up" methods, and behaviorally targeted search result generation.
- Key Procedural History: The complaint does not reference any prior litigation or licensing history for the asserted patents. However, public records indicate that U.S. Patent No. 7,269,127, one of the patents-in-suit, was the subject of an Inter Partes Review (IPR2014-01185), which resulted in the cancellation of claims 1-10 and 17. The complaint asserts claim 20 of this patent, which was not affected by the IPR proceeding.
Case Timeline
| Date | Event |
|---|---|
| 2001-10-04 | Earliest Priority Date for U.S. Patent No. 7,269,127 |
| 2003-03-05 | Earliest Priority Date for U.S. Patent No. 7,653,031 |
| 2003-03-25 | Earliest Priority Date for U.S. Patent No. 7,483,878 |
| 2004-07-21 | Earliest Priority Date for U.S. Patent No. 7,676,007 |
| 2004-07-30 | Earliest Priority Date for U.S. Patent No. 8,139,544 |
| 2004-11-24 | Earliest Priority Date for U.S. Patent Nos. 7,398,408 & 8,812,888 |
| 2005-04-26 | Earliest Priority Date for U.S. Patent No. 7,949,068 |
| 2007-09-11 | Issue Date for U.S. Patent No. 7269127 |
| 2008-07-08 | Issue Date for U.S. Patent No. 7398408 |
| 2009-01-27 | Issue Date for U.S. Patent No. 7483878 |
| 2010-01-26 | Issue Date for U.S. Patent No. 7653031 |
| 2010-03-09 | Issue Date for U.S. Patent No. 7676007 |
| 2011-05-24 | Issue Date for U.S. Patent No. 7949068 |
| 2012-03-20 | Issue Date for U.S. Patent No. 8139544 |
| 2014-08-19 | Issue Date for U.S. Patent No. 8812888 |
| 2018-06-28 | Date of Inter Partes Review Certificate cancelling claims of the '127 Patent |
| 2025-11-24 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,483,878 - "Generation and Presentation of Search Results Using Addressing Information"
Issued January 27, 2009 (’878 Patent)
The Invention Explained
- Problem Addressed: The patent's background describes online users being "overwhelmed with irrelevant advertisements" that are displayed without intelligence as to the user's actual interests, leading to screen clutter and an inefficient experience (’878 Patent, col. 1:28-40).
- The Patented Solution: The invention proposes a method where a client computer receives "addressing information" (such as a URL) identifying a user's location on a network. This information is processed to generate a relevant keyword. A search is then performed on that keyword, and the results are presented to the user in a "presentation vehicle," such as a pop-under window, in response to the user navigating to that location (’878 Patent, Abstract; Fig. 1). This shifts the generation of related content from a generic server-side push to a client-triggered, context-aware pull.
- Technical Importance: This approach sought to improve the relevance of supplementary content or advertisements by directly tying them to a user's explicit browsing behavior at the moment of navigation, rather than relying on less timely or generic targeting methods (’878 Patent, col. 2:40-52).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶22).
- Claim 1 is a method claim with the following essential elements:
- receiving addressing information identifying a location in a computer network;
- processing the addressing information to generate a keyword;
- performing a search on the keyword to generate a search result; and
- presenting an end-user the search result responsive to the keyword that is based on the addressing information in response to the end-user navigating to the location using a client computer.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 7,676,007 - "System and Method for Interpolation Based Transmit Beamforming for MIMO-OFDM with Partial Feedback"
Issued March 9, 2010 (’007 Patent)
The Invention Explained
- Problem Addressed: In advanced MIMO-OFDM wireless systems, the transmitter requires channel state information from the receiver to perform optimal beamforming. Providing this feedback for all frequency subcarriers creates significant overhead, which consumes bandwidth and reduces overall system efficiency (’007 Patent, col. 2:39-44).
- The Patented Solution: The invention proposes that the receiver send back beamforming information for only a subset of the subcarriers ("partial feedback"). The transmitter then uses this partial data, along with specific "interpolation information" (including phase values) also supplied by the receiver, to mathematically derive or "interpolate" the beamforming vectors for the subcarriers for which no explicit feedback was provided (’007 Patent, Abstract; col. 2:45-51).
- Technical Importance: This method provides a way to reduce the feedback overhead required for closed-loop MIMO systems, addressing a critical trade-off between achieving high performance through beamforming and maintaining high data throughput by minimizing non-data transmissions (’007 Patent, col. 1:25-45).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶49).
- Claim 1 is an apparatus claim with the following essential elements:
- A plurality of antennas;
- A transmitter coupled to the antennas, configured to provide output signals on a plurality of subcarriers in response to limited feedback information received from a receiver;
- The limited feedback information includes "interpolation information" and "beamforming vectors for a subset of the subcarriers";
- The transmitter is configured to derive beamforming vectors for subcarriers not in the subset based on an interpolation of the beamforming vectors for the subset;
- The interpolation is based at least in part on the interpolation information, which includes "phase values."
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 7,653,031 - "Advance Notification of Transmit Opportunities On A Shared-Communications Channel"
Issued January 26, 2010 (’031 Patent)
- Technology Synopsis: The patent addresses the problem of two different wireless protocols (e.g., IEEE 802.11 Wi-Fi and Bluetooth) interfering with each other when operating on the same shared channel (’031 Patent, col. 1:40-52). The solution involves a "first air interface subsystem" (e.g., Wi-Fi) determining a future "transmit opportunity" based on its own network timing (e.g., the beacon interval) and notifying a "second air interface subsystem" (e.g., Bluetooth) in advance, allowing the second system to use the channel without collision (’031 Patent, Abstract).
- Asserted Claims: At least independent claim 15 is asserted (Compl. ¶76).
- Accused Features: The complaint accuses "D-Link 802.11/BT Compatible Devices" of infringement, alleging they comprise two air interface subsystems that coordinate access to a shared channel (Compl. ¶77).
U.S. Patent No. 7,398,408 - "Systems and Methods for Waking Up Wireless LAN Devices"
Issued July 8, 2008 (’408 Patent)
- Technology Synopsis: The patent describes a method to wake a computing device from a low-power or sleep state over a wireless network (’408 Patent, col. 1:7-12). A device broadcasts a signal containing a specific "wake-up data sequence." A sleeping device, operating in a reduced power mode, periodically scans wireless channels for this sequence and, upon detecting a match, restores itself to full power (’408 Patent, Abstract).
- Asserted Claims: At least independent claim 1 is asserted (Compl. ¶103).
- Accused Features: The "D-Link Bluetooth Devices" are accused of performing the claimed method of broadcasting and receiving a wake-up sequence to manage power states (Compl. ¶104).
U.S. Patent No. 8,812,888 - "Systems and Methods for Scanning for A Wake Up Packet Addressed to A Wireless Device"
Issued August 19, 2014 (’888 Patent)
- Technology Synopsis: This patent, related to the ’408 Patent, focuses on the power-saving behavior of the sleeping device. It claims a method where the device scans for a wake-up packet for a predetermined period and, if the packet is not received within that time, ceases scanning to conserve energy before potentially scanning again later (’888 Patent, Abstract).
- Asserted Claims: At least independent claim 1 is asserted (Compl. ¶113).
- Accused Features: The "D-Link Bluetooth Devices" are accused of performing this method of time-limited scanning for wake-up packets while in a low-power mode (Compl. ¶114).
U.S. Patent No. 7,949,068 - "Systems and Methods for Transmitter Diversity"
Issued May 24, 2011 (’068 Patent)
- Technology Synopsis: The patent discloses a method for transmitter diversity to improve signal robustness. It describes generating a set of "extension data streams" based on a set of "base data streams" by performing a "matrix multiplication... with a unitary matrix." Both the base and the new extension streams are then transmitted from separate antennas (’068 Patent, Abstract).
- Asserted Claims: At least independent claim 17 is asserted (Compl. ¶123).
- Accused Features: The "D-Link 802.11n Compatible Devices" are accused of performing this method of generating and transmitting base and extension data streams (Compl. ¶124).
U.S. Patent No. 8,139,544 - "Pilot Tone Processing Systems and Methods"
Issued March 20, 2012 (’544 Patent)
- Technology Synopsis: This patent addresses signal processing in a receiver. It describes a system that receives two distinct signals (e.g., from two transmit antennas), each containing data subcarriers and pilot subcarriers. The receiver is configured to separate the data and pilot subcarriers from both signals based on channel estimates and then "match-filter combine" the pilot subcarriers from the respective signals to improve signal quality and aid in correcting distortions (’544 Patent, Abstract).
- Asserted Claims: At least independent claim 15 is asserted (Compl. ¶149).
- Accused Features: The complaint alleges that "D-Link 802.11n Compatible Devices" infringe by providing a system that receives and separates signals containing data and pilot subcarriers and performs match-filter combining (Compl. ¶150).
U.S. Patent No. 7,269,127 - "Preamble Structures for Single-Input, Single-Output (SISO) and Multi-Input, Multi-Output (MIMO) Communication Systems"
Issued September 11, 2007 (’127 Patent)
- Technology Synopsis: The patent details a specific method of forming a frame structure for transmission in a wireless communication system. The method involves providing data and training blocks, combining them in a parallel format, taking an inverse discrete Fourier transform (IDFT), inserting cyclic prefixes to form symbols, and converting the parallel symbols to a serial format to create a preamble and data structure with specific defined characteristics (’127 Patent, Abstract).
- Asserted Claims: At least independent claim 20 is asserted (Compl. ¶175).
- Accused Features: The "D-Link 802.11n Compatible Devices" are accused of performing this specific method of forming and transmitting a frame structure (Compl. ¶176).
III. The Accused Instrumentality
Product Identification
The complaint targets an extensive range of D-Link's networking products, broadly categorized as "D-Link Websites," "802.11n Compatible Devices," "802.11ac Compatible Devices," "Bluetooth compatible devices," and "802.11/BT Compatible Devices" (Compl. ¶12). Dozens of specific model numbers for routers, cameras, adapters, and access points are listed as non-limiting examples (Compl. ¶12, pp. 4-16).
Functionality and Market Context
The complaint alleges that these products, collectively, implement the functionalities recited in the asserted patents. This includes providing web-based search results (’878 Patent), utilizing advanced MIMO-OFDM techniques like beamforming (’007 Patent), enabling coexistence between Wi-Fi and Bluetooth radios (’031 Patent), implementing wireless wake-up protocols (’408 and ’888 Patents), and employing specific methods of data transmission and signal processing required by various wireless standards (’068, ’544, ’127 Patents) (Compl. ¶¶23, 50, 77, 104, 114, 124, 150, 176). The complaint alleges Defendant is a significant distributor and seller of these home security and networking systems in the United States and Texas (Compl. ¶¶8, 12, 14). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’878 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a method... comprising: receiving addressing information identifying a location in a computer network; | Defendant, through the D-Link Websites, receives addressing information that identifies a location. | ¶23 | col. 2:40-42 |
| processing the addressing information to generate a keyword; | The D-Link Websites process the addressing information to generate a keyword. | ¶23 | col. 2:45-47 |
| performing a search on the keyword to generate a search result; | The D-Link Websites perform a search on the generated keyword to create a search result. | ¶23 | col. 2:47-49 |
| and presenting an end-user the search result responsive to the keyword that is based on the addressing information in response to the end-user navigating to the location using a client compute. | The D-Link Websites present the search result to the end-user in response to the user's navigation. | ¶23 | col. 2:49-52 |
’007 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A communication apparatus, comprising: a plurality of antennas; and a transmitter coupled to the antennas and configured to provide...output signals on a plurality of subcarriers...in response to...limited feedback information; | D-Link 802.11ac Compatible Devices provide a communication apparatus with antennas and a transmitter that provides output signals in response to limited feedback. | ¶50 | col. 2:45-51 |
| the transmitter is configured to receive the limited feedback information from the receiver; | The transmitter in the accused devices is configured to receive the limited feedback. | ¶50 | col. 4:8-10 |
| the limited feedback information includes interpolation information and beamforming vectors for a subset of the subcarriers; | The feedback information allegedly includes interpolation information and beamforming vectors for a subset of subcarriers. | ¶50 | col. 4:4-7 |
| the transmitter is configured to derive beamforming vectors for at least one subcarrier...not included in the subset based at least on an interpolation of the beamforming vectors for a subset of the subcarriers; | The transmitter in the accused devices is configured to derive beamforming vectors for the remaining subcarriers via interpolation. | ¶50 | col. 3:45-51 |
| the interpolation is based at least in part on the interpolation information; and the interpolation information includes phase values. | The alleged interpolation is based on interpolation information that includes phase values. | ¶50 | col. 3:52-55 |
Identified Points of Contention
- Scope Questions: For the ’878 Patent, a central question may be one of scope. The patent's primary embodiment describes a client-side program that monitors navigation to a third-party website and triggers a separate "presentation vehicle" (’878 Patent, col. 4:55-63). The complaint accuses D-Link's own websites of infringement (Compl. ¶23). This raises the question of whether a website's internal search function, performed after a user has already navigated to that website, meets the claim limitation of presenting a search result "in response to the end-user navigating to the location."
- Technical Questions: For the ’007 Patent and other highly technical patents, the complaint's allegations are largely conclusory, tracking the claim language without providing specific technical evidence (Compl. ¶50). A key question for the court will be evidentiary: what proof does the complaint or subsequent discovery provide that D-Link's standard-compliant 802.11ac products practice the specific "interpolation" method using "phase values" as required by the claims, rather than alternative, non-infringing methods for handling partial feedback that may also be part of the relevant wireless standards?
V. Key Claim Terms for Construction
’878 Patent, Claim 1
- The Term: "in response to the end-user navigating to the location"
- Context and Importance: The definition of this phrase is critical to determining the scope of the claimed method. Practitioners may focus on this term because its interpretation will decide whether the claim covers only systems that automatically trigger upon the act of navigation (as the patent's embodiment suggests) or more broadly covers any search performed at the destination location.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The plain language of the claim, read in isolation, could suggest that any action that follows or is a consequence of navigation is "in response to" it.
- Evidence for a Narrower Interpretation: The specification's detailed description focuses on a "client program resident in a client computer monitor[ing] an end-user's web browsing activity" and triggering the delivery of search results (’878 Patent, col. 2:40-44). This context suggests the "response" is an automatic action by a monitoring program based on the navigation event, not a user-initiated search on the destination website itself.
’007 Patent, Claim 1
- The Term: "interpolation information"
- Context and Importance: This term is central to the claimed invention's method for reducing feedback. The claim requires that this information "includes phase values." The dispute will likely hinge on whether the feedback mechanism in the accused products contains data that qualifies as "interpolation information" specifically including "phase values" for the purpose of interpolation, as opposed to other types of feedback data.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue that any phase-related data transmitted from the receiver to the transmitter as part of a feedback scheme could be construed as "interpolation information."
- Evidence for a Narrower Interpretation: The specification describes the "interpolation information" as parameters found by the receiver specifically "for phase rotation" in order to "minimiz[ing] the distortion induced by interpolation" (’007 Patent, col. 4:6-10). This language suggests the term refers not to arbitrary phase data, but to specific parameters calculated for and used by the claimed interpolation process.
VI. Other Allegations
- Indirect Infringement: For each asserted patent, the complaint alleges induced infringement based on Defendant's actions, such as distributing instructions, user manuals, and providing technical support that allegedly guide end-users to use the Accused Products in an infringing manner (Compl. ¶¶27-29, 54-56). The complaint also alleges contributory infringement, stating the Accused Products have special features designed for infringement with no substantial non-infringing uses (Compl. ¶¶33-36, 60-63).
- Willful Infringement: The complaint alleges that Defendant had actual knowledge of each patent "since at least the time of receiving the original complaint in this action," providing a basis for post-suit willfulness (Compl. ¶¶25, 52). It also alleges pre-suit willful blindness by claiming Defendant has a "policy or practice of not reviewing the patents of others" (Compl. ¶¶24, 51).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of applicability and scope: For patents like the ’878 Patent, can the invention as described and claimed—which appears to contemplate a client-side agent monitoring third-party web navigation—be construed to cover the functionality of a party's own website search engine? This raises a fundamental question of whether the accused conduct matches the patented method.
- A second key issue will be one of evidentiary proof: For the highly technical wireless communication patents (’007, ’068, ’544, etc.), the complaint provides conclusory allegations that mirror claim language. The case will likely turn on whether the plaintiff can produce concrete technical evidence (e.g., through reverse engineering or source code analysis) demonstrating that D-Link’s standard-compliant products implement the specific, and potentially proprietary, processing methods claimed, as opposed to other non-infringing methods permitted by or common to the 802.11n/ac standards.
- A final question will be one of validity exposure: Given that claims from the ’127 Patent were previously cancelled in an Inter Partes Review, the asserted claims of the remaining patents may face heightened scrutiny. An open question is whether the defendant will leverage similar prior art or invalidity arguments in new IPR petitions against the other patents-in-suit, potentially narrowing the scope of the litigation before it reaches trial.