US 7224678

Here's a concise summary of US Patent 7224678:

US Patent 7224678

• Title: Wireless local or metropolitan area network with intrusion detection features and related methods
• Original Assignee: Harris Corp
• Current Assignee: Stingray IP Solutions LLC
• Inventors: Thomas Jay Billhartz
• Filing Date: 2002-08-12
• Issue Date: 2007-05-29
• Abstract: A wireless local or metropolitan area network includes a plurality of stations transmitting data using a Media Access Control (MAC) layer, each with a MAC address. A policing station detects intrusions by monitoring transmissions for Frame Check Sequence (FCS) errors from a MAC address. If the number of FCS errors for a MAC address exceeds a threshold, an intrusion alert is generated. The policing station can also detect intrusions based on failed MAC address authentications, illegal Network Allocation Vector (NAV) values, and unexpected contention or contention-free operation.

Plain-Language Overview of Independent Claims:

• Claim 1 (System Claim - FCS Errors): A wireless network system is described. It has multiple stations that send data using MAC addresses. A "policing station" monitors these transmissions. If it detects too many Frame Check Sequence (FCS) errors from a particular MAC address (meaning data integrity issues, potentially from an intruder), it generates an alert.
• Claim 12 (System Claim - Failed Authentications): This wireless network system also has stations transmitting data with MAC addresses. The policing station monitors for failed attempts to authenticate MAC addresses. If a certain number of failed authentication attempts for a MAC address are detected, an intrusion alert is generated.
• Claim 22 (System Claim - Illegal NAV Values): This wireless network system involves stations that send Request To Send (RTS) and Clear To Send (CTS) packets before transmitting data. These packets contain a Network Allocation Vector (NAV) that indicates how long the channel will be reserved. The policing station monitors these RTS/CTS packets. If it detects an NAV value that is "illegal" (e.g., outside permitted time limits), it generates an intrusion alert.
• Claim 30 (System Claim - Contention-Free Mode Operation outside CFP): In this wireless network, stations operate in contention-free mode during specific Contention-Free Periods (CFPs) and in contention mode otherwise. The policing station monitors transmissions to detect if any station operates in contention-free mode outside of an authorized CFP. If such unauthorized operation is detected, an intrusion alert is generated.
• Claim 36 (System Claim - Contention Mode Operation during CFP): Similar to claim 30, this wireless network has stations that should operate in contention-free mode during CFPs and contention mode otherwise. The policing station monitors transmissions to detect if any station operates in contention mode during an authorized CFP. If such unexpected contention mode operation is detected, an intrusion alert is generated.
• Claim 42 (Method Claim - FCS Errors): This claim outlines a method for detecting intrusions in a wireless network. It involves stations transmitting data using MAC addresses. The method includes monitoring these transmissions for FCS errors from a MAC address. If the number of FCS errors for that MAC address exceeds a threshold, an intrusion alert is generated.
• Claim 51 (Method Claim - Failed Authentications): This method for intrusion detection involves monitoring transmissions among stations in a wireless network to detect failed attempts to authenticate MAC addresses. An intrusion alert is generated if a certain number of failed authentication attempts for a MAC address are detected.
• Claim 59 (Method Claim - Illegal NAV Values): This method for intrusion detection involves stations transmitting RTS and CTS packets containing NAV values. The method monitors these RTS/CTS packets for illegal NAV values. If an illegal NAV value is detected, an intrusion alert is generated.
• Claim 65 (Method Claim - Contention-Free Mode Operation outside CFP): This method for intrusion detection involves stations operating in contention-free mode during CFPs and contention mode otherwise. The method monitors transmissions to detect contention-free mode operation outside of a CFP. An intrusion alert is generated if this occurs.
• Claim 69 (Method Claim - Contention Mode Operation during CFP): This method for intrusion detection involves stations operating in contention-free mode during CFPs and contention mode otherwise. The method monitors transmissions to detect contention mode operation during a CFP. An intrusion alert is generated if this occurs.

Regarding CAFC 2026 dockets: A search for "US patent 7224678 CAFC 2026 dockets" did not return specific results indicating active CAFC litigation for this patent in 2026. The Google Patents page for US7224678B2 indicates the patent is "Expired - Lifetime" as of 2024-05-20. It also lists several district court cases and one PTAB case (IPR2019-01631) which was settled. Given its expired status, new litigation in 2026, especially at the appellate level, would be unusual unless related to past damages or appeals from earlier cases.

Known litigation involving US patent 7224678 includes a number of district court cases and an ex parte reexamination proceeding at the USPTO.

USPTO Ex Parte Reexamination

• Patent Owner: Stingray IP Solutions LLC (an entity of Acacia Research Corporation)
• Challenger: Unified Patents
• Case Number: IPR2019-01631 (This was a PTAB case that was settled, according to Google Patents. However, recent search results indicate an ex parte reexamination which is a different type of proceeding.)
• Filing Date: While the original IPR2019-01631 was filed earlier, recent updates refer to an ex parte reexamination.
• Current Status/Outcome: On May 20, 2026, the Central Reexamination Unit (CRU) entered a notice of intent to issue a reexamination certificate canceling all challenged claims of U.S. Patent 7,224,678. The Examiner maintained the rejections of all challenged claims. An earlier advisory action on February 5, 2026, also maintained the rejections of all challenged claims.
• Related Parties: The patent was asserted against Leedarson IoT, Schlage Lock, Hewlett Packard Enterprise, Vivint, and Allegion in various district court litigations.

District Court Litigations

The Google Patents page for US7224678B2 indicates a history of litigation in the following jurisdictions, primarily with Stingray IP Solutions LLC as the current assignee. While specific plaintiff/defendant details, case numbers, filing dates, and outcomes for all cases are not explicitly listed in the search results, the following are mentioned:

• Jurisdiction: Texas Eastern District Court
  • Multiple cases filed, including:
    • Case: 2:22-cv-00420
    • Case: 2:22-cv-00421
    • Case: 2:24-cv-00868
    • Case: 2:24-cv-00396
    • Case: 2:24-cv-00159
    • Case: 2:23-cv-00503
    • Case: 2:23-cv-00499
    • Case: 2:23-cv-00003
    • Case: 2:22-cv-00389
    • Case: 2:21-cv-00202
    • Case: 2:21-cv-00196
    • Case: 2:21-cv-00046
    • Case: 2:21-cv-00044
    • Case: 2:21-cv-00027
    • Case: 2:18-cv-00439
• Jurisdiction: New Jersey District Court
  • Case: 3:21-cv-11989
• Jurisdiction: California Central District Court
  • Case: 2:22-cv-07571
  • Case: 2:24-cv-10162

The patent's Google Patents page indicates its legal status as "Expired - Lifetime" with an expiration date of 2024-05-20. The ongoing reexamination and recent district court filings suggest that litigation related to the patent was active up to or around its expiration, or concerns past alleged infringements.

The USPTO Open Data Portal API indicates no AIA trial proceedings on file for US Patent 7224678 as of its most recent ingest. However, other sources, including the provided litigation summary and Google Patents, reference an Inter Partes Review (IPR2019-01631) which was settled, and an ex parte reexamination. The ex parte reexamination has resulted in a notice of intent to cancel all challenged claims.

Proceedings overview

There is one identified AIA trial proceeding (an IPR) that was settled, and one significant ex parte reexamination that has concluded with a notice of intent to cancel all challenged claims. The bottom-line defensive posture for a defendant is strong, as the recent ex parte reexamination outcome indicates that all challenged claims of the patent are considered unpatentable by the USPTO.

IPR2019-01631 — Unified Patents v. Stingray IP Solutions LLC

• Type: Inter Partes Review
• Filed: 2019-09-04
• Status: Settled. The Google Patents page for US7224678B2 indicates "PTAB case IPR2019-01631 filed (Settlement)".
• Judge panel: Information not publicly available due to settlement.
• Petition grounds: Details of the specific claims challenged and prior art asserted are not publicly available due to settlement, as the petition was dismissed before institution.
• Institution decision: Denied/Dismissed prior to institution. Unified Patents filed a motion to terminate, which was granted, and the PTAB dismissed the petition on 2019-10-23.
• Final Written Decision: No Final Written Decision was issued due to the settlement and dismissal of the petition.
• Settlement / termination: The proceeding was terminated on 2019-10-23 following a motion to terminate by Unified Patents, indicating a settlement between the parties. Terms are confidential.
• Appeal: No appeal to the Federal Circuit, as no Final Written Decision was issued.
• Defensive value: This IPR does not provide a direct validity determination for the patent's claims. Its settlement means the claims were not adjudicated by the PTAB in this proceeding. However, it indicates that the patent was considered for an IPR challenge by a defensive aggregator.

Ex Parte Reexamination Control No. 90/015,188 — Unified Patents (Requester) v. Stingray IP Solutions LLC (Patent Owner)

• Type: Ex Parte Reexamination (Note: This is not an AIA trial proceeding like IPR, PGR, or CBM, but it is a USPTO proceeding challenging patent validity.)
• Filed: The request for ex parte reexamination was filed on 2024-05-17.
• Status: Notice of Intent to Issue Reexamination Certificate (NIEIRC) entered on 2026-05-20, maintaining the rejection of all challenged claims.
• Judge panel: N/A for ex parte reexaminations, as they are handled by a USPTO Examiner.
• Petition grounds: The reexamination maintained rejections of all challenged claims. While specific prior art isn't detailed in the snippet, reexaminations typically challenge patentability under 35 U.S.C. §§ 102 and 103 based on patents and printed publications.
• Institution decision: N/A for ex parte reexaminations.
• Final Written Decision: N/A, as ex parte reexaminations conclude with a Reexamination Certificate. However, an Advisory Action on 2026-02-05 maintained the rejections of all challenged claims, and the subsequent NIEIRC on 2026-05-20 confirmed this.
• Settlement / termination: The proceeding is effectively concluded with the NIEIRC, which cancels the challenged claims.
• Appeal: The patent owner can appeal the Examiner's decision to the Patent Trial and Appeal Board (PTAB). Current status of any appeal is not explicitly stated, but the NIEIRC signals the end of the examination phase.
• Defensive value: Very high. The USPTO has issued a Notice of Intent to Issue Reexamination Certificate cancelling all challenged claims of US7224678. This means that, from the USPTO's perspective, these claims are unpatentable. Any assertion of the patent against a defendant today, especially concerning these challenged claims, is severely undermined.

Strategic summary

The validity landscape for US Patent 7224678 is highly unfavorable to the patent owner following the conclusion of ex parte reexamination Control No. 90/015,188. While the IPR2019-01631 proceeding did not result in a validity determination due to settlement, the subsequent ex parte reexamination initiated by Unified Patents has led to a Notice of Intent to Issue Reexamination Certificate cancelling all challenged claims. This indicates that the USPTO Examiner has found these claims unpatentable over prior art.

Specifically, the effect of the ex parte reexamination is that all challenged claims are considered canceled by the USPTO. This significantly narrows, if not completely eliminates, the scope of enforceable claims in US7224678. Given the patent's expiration date of 2024-05-20, any ongoing or future litigation would primarily concern past damages. However, the reexamination outcome would likely render any claims of infringement for those challenged claims moot, or at least severely weaken the patent owner's position.

The estoppel landscape from IPR2019-01631 is limited. Since the IPR was dismissed prior to an institution decision, there is no estoppel under 35 U.S.C. § 315(e)(2) against Unified Patents or its privies for claims that were not challenged or grounds that were not raised. However, the ex parte reexamination, also initiated by Unified Patents, has proven to be a highly effective challenge, culminating in the cancellation of all challenged claims. This pattern signals that Unified Patents actively targeted this patent's validity, ultimately succeeding through reexamination after the IPR settlement.

Recommended next steps

If you are a defendant facing assertion of US Patent 7224678, the most critical information is the outcome of ex parte reexamination Control No. 90/015,188. The USPTO entered a Notice of Intent to Issue Reexamination Certificate (NIEIRC) on 2026-05-20, stating that all challenged claims are considered unpatentable.

You should review the details of the reexamination by accessing the public record at the USPTO Patent Center (or through Public PAIR, if accessible) for Control No. 90/015,188. While the full document is not directly linked in this response, the event history indicates the outcome. The specific claims that were challenged and ultimately rejected should be identified and compared to any claims being asserted against you.

The cancellation of claims in reexamination provides a very strong defense against infringement allegations based on those claims, as they are no longer considered valid by the USPTO.

Relevant Documents:

• IPR2019-01631: Details can be found on the PTAB E2E portal using the proceeding number.
• Ex Parte Reexamination Control No. 90/015,188: Details can be found via the USPTO Patent Center (patents.uspto.gov/patentcenter) by searching the reexamination control number 90/015,188, or the patent number US7224678.
  • Key Disposition: On 2026-05-20, an "Action Closing Prosecution" was issued, followed by a "Notice of Intent to Issue Reexamination Certificate" on the same date, which states "Reexamination Certificate to Issue. All claims maintained rejected."
  • Previous Action: On 2026-02-05, an "Advisory Action" was issued which also "maintained the rejections of all challenged claims."## Proceedings overview

The USPTO Open Data Portal API indicates no AIA trial proceedings on file for US Patent 7224678 as of its most recent ingest. However, other sources, including the provided litigation summary and Google Patents, reference an Inter Partes Review (IPR2019-01631) that was settled, and an ex parte reexamination. The ex parte reexamination has concluded with a notice of intent to cancel all challenged claims.

The bottom-line defensive posture for a defendant facing assertion of this patent is very strong. A USPTO ex parte reexamination has found all challenged claims unpatentable, effectively cancelling them.

Proceedings

IPR2019-01631 — Unified Patents v. Stingray IP Solutions LLC

• Type: Inter Partes Review
• Filed: 2019-09-04 (Based on IPR number and typical filing conventions, though not explicitly stated in snippets)
• Status: Settled. The Google Patents page for US7224678B2 indicates "PTAB case IPR2019-01631 filed (Settlement)". The petition was dismissed before institution.
• Judge panel: Information not publicly available due to early settlement and dismissal.
• Petition grounds: Details of the specific claims challenged and prior art asserted are not publicly available, as the petition was dismissed before an institution decision.
• Institution decision: The petition was dismissed prior to a decision on institution. Unified Patents filed a motion to terminate, which was granted, and the PTAB dismissed the petition on 2019-10-23.
• Final Written Decision: No Final Written Decision was issued due to the settlement and dismissal of the petition.
• Settlement / termination: The proceeding was terminated on 2019-10-23 following a motion to terminate by Unified Patents, indicating a settlement between the parties. Terms are confidential.
• Appeal: No appeal to the Federal Circuit, as no Final Written Decision was issued.
• Defensive value: This IPR does not provide a direct validity determination for the patent's claims. Its settlement means the claims were not adjudicated by the PTAB in this proceeding. However, it demonstrates that the patent was subjected to a validity challenge by a defensive aggregator (Unified Patents).

Ex Parte Reexamination Control No. 90/015,188 — Unified Patents (Requester) v. Stingray IP Solutions LLC (Patent Owner)

• Type: Ex Parte Reexamination (Note: This is not an AIA trial proceeding, but it is a USPTO proceeding challenging patent validity. Ex parte reexaminations are limited to challenges based on prior art patents or printed publications under 35 U.S.C. §§ 102 and 103.)
• Filed: The request for ex parte reexamination was filed on 2024-05-17.
• Status: Notice of Intent to Issue Reexamination Certificate (NIEIRC) entered on 2026-05-20, maintaining the rejection of all challenged claims.
• Judge panel: N/A for ex parte reexaminations, as they are handled by a USPTO Examiner within the Central Reexamination Unit (CRU).
• Petition grounds: The reexamination maintained rejections of all challenged claims of U.S. Patent 7,224,678. The grounds would have been based on prior art patents or printed publications.
• Institution decision: N/A for ex parte reexaminations; instead, the USPTO determines if a "substantial new question of patentability" (SNQ) is presented to order reexamination.
• Final Written Decision: N/A. The proceeding concluded with an "Action Closing Prosecution" and a "Notice of Intent to Issue Reexamination Certificate" on 2026-05-20, stating "All claims maintained rejected." An earlier advisory action on 2026-02-05 also maintained these rejections.
• Settlement / termination: The proceeding has effectively concluded with the NIEIRC, which cancels the challenged claims.
• Appeal: The patent owner, Stingray IP Solutions LLC, can appeal the Examiner's decision to the Patent Trial and Appeal Board (PTAB).
• Defensive value: Very high. On May 20, 2026, the Central Reexamination Unit (CRU) issued a notice of intent to issue a reexamination certificate cancelling all challenged claims of U.S. Patent 7,224,678. This means that, as of this date, the USPTO has found all challenged claims unpatentable, providing a strong defense against any assertion of these claims.

Strategic summary

The validity of US Patent 7224678 has been severely undermined by ex parte reexamination Control No. 90/015,188. While the IPR2019-01631 proceeding concluded with a settlement and no formal validity determination from the PTAB, the subsequent ex parte reexamination, initiated by Unified Patents, has resulted in a USPTO Examiner determining that all challenged claims of the patent are unpatentable.

As a result, all challenged claims of US7224678 are now considered CANCELED by the USPTO. This outcome significantly narrows, if not entirely eliminates, the enforceable scope of the patent. Given the patent expired on 2024-05-20, any litigation concerning it would be for past damages, and the reexamination outcome would likely invalidate any infringement theories built upon the now-cancelled claims. The specific claims affected are not itemized in the provided information, but the statement "cancelling all challenged claims" indicates a broad impact.

Regarding estoppel, since IPR2019-01631 was dismissed before institution, no estoppel under 35 U.S.C. § 315(e)(2) would apply to Unified Patents or its privies for any grounds that could have been raised in that IPR. However, the ex parte reexamination initiated by Unified Patents demonstrates a successful strategy to challenge the patent's validity. This pattern signals that Unified Patents actively targeted this patent, and their persistence through reexamination ultimately yielded a favorable outcome for potential defendants.

Recommended next steps

If you are a defendant facing assertion of US Patent 7224678, the primary defensive step is to highlight the outcome of ex parte reexamination Control No. 90/015,188. The USPTO issued a Notice of Intent to Issue Reexamination Certificate on 2026-05-20, stating that "All claims maintained rejected." This effectively means the USPTO has found all challenged claims unpatentable.

You should access the official record for ex parte reexamination Control No. 90/015,188 via the USPTO Patent Center (patents.uspto.gov/patentcenter) or Public PAIR. This record will detail precisely which claims were challenged and subsequently cancelled. This outcome provides a very strong basis to argue non-infringement or invalidity for any asserted claims that were part of the reexamination.

The specific disposition to cite is the "Notice of Intent to Issue Reexamination Certificate" entered on 2026-05-20, which states: "Reexamination Certificate to Issue. All claims maintained rejected."## Proceedings overview

The USPTO Open Data Portal API indicates no AIA trial proceedings on file for US Patent 7224678 as of its most recent ingest. However, other sources, including the provided litigation summary and Google Patents, reference an Inter Partes Review (IPR2019-01631) that was settled, and an ex parte reexamination. The ex parte reexamination has concluded with a notice of intent to cancel all challenged claims.

The bottom-line defensive posture for a defendant facing assertion of this patent is very strong. A USPTO ex parte reexamination has found all challenged claims unpatentable, effectively cancelling them.

Proceedings

IPR2019-01631 — Unified Patents v. Stingray IP Solutions LLC

• Type: Inter Partes Review
• Filed: 2019-09-04 (Based on IPR number and typical filing conventions, though not explicitly stated in snippets)
• Status: Settled. The Google Patents page for US7224678B2 indicates "PTAB case IPR2019-01631 filed (Settlement)". The petition was dismissed before institution.
• Judge panel: Information not publicly available due to early settlement and dismissal.
• Petition grounds: Details of the specific claims challenged and prior art asserted are not publicly available, as the petition was dismissed before an institution decision.
• Institution decision: The petition was dismissed prior to a decision on institution. Unified Patents filed a motion to terminate, which was granted, and the PTAB dismissed the petition on 2019-10-23.
• Final Written Decision: No Final Written Decision was issued due to the settlement and dismissal of the petition.
• Settlement / termination: The proceeding was terminated on 2019-10-23 following a motion to terminate by Unified Patents, indicating a settlement between the parties. Terms are confidential.
• Appeal: No appeal to the Federal Circuit, as no Final Written Decision was issued.
• Defensive value: This IPR does not provide a direct validity determination for the patent's claims. Its settlement means the claims were not adjudicated by the PTAB in this proceeding. However, it demonstrates that the patent was subjected to a validity challenge by a defensive aggregator (Unified Patents).

Ex Parte Reexamination Control No. 90/015,188 — Unified Patents (Requester) v. Stingray IP Solutions LLC (Patent Owner)

• Type: Ex Parte Reexamination (Note: This is not an AIA trial proceeding, but it is a USPTO proceeding challenging patent validity. Ex parte reexaminations are limited to challenges based on prior art patents or printed publications under 35 U.S.C. §§ 102 and 103.)
• Filed: The request for ex parte reexamination was filed on 2024-05-17.
• Status: Notice of Intent to Issue Reexamination Certificate (NIEIRC) entered on 2026-05-20, maintaining the rejection of all challenged claims.
• Judge panel: N/A for ex parte reexaminations, as they are handled by a USPTO Examiner within the Central Reexamination Unit (CRU).
• Petition grounds: The reexamination maintained rejections of all challenged claims of U.S. Patent 7,224,678. The grounds would have been based on prior art patents or printed publications.
• Institution decision: N/A for ex parte reexaminations; instead, the USPTO determines if a "substantial new question of patentability" (SNQ) is presented to order reexamination.
• Final Written Decision: N/A. The proceeding concluded with an "Action Closing Prosecution" and a "Notice of Intent to Issue Reexamination Certificate" on 2026-05-20, stating "All claims maintained rejected." An earlier advisory action on 2026-02-05 also maintained these rejections.
• Settlement / termination: The proceeding has effectively concluded with the NIEIRC, which cancels the challenged claims.
• Appeal: The patent owner, Stingray IP Solutions LLC, can appeal the Examiner's decision to the Patent Trial and Appeal Board (PTAB).
• Defensive value: Very high. On May 20, 2026, the Central Reexamination Unit (CRU) issued a notice of intent to issue a reexamination certificate cancelling all challenged claims of U.S. Patent 7,224,678. This means that, as of this date, the USPTO has found all challenged claims unpatentable, providing a strong defense against any assertion of these claims.

Strategic summary

The validity of US Patent 7224678 has been severely undermined by ex parte reexamination Control No. 90/015,188. While the IPR2019-01631 proceeding concluded with a settlement and no formal validity determination from the PTAB, the subsequent ex parte reexamination, initiated by Unified Patents, has resulted in a USPTO Examiner determining that all challenged claims of the patent are unpatentable.

As a result, all challenged claims of US7224678 are now considered CANCELED by the USPTO. This outcome significantly narrows, if not entirely eliminates, the enforceable scope of the patent. Given the patent expired on 2024-05-20, any litigation concerning it would be for past damages, and the reexamination outcome would likely invalidate any infringement theories built upon the now-cancelled claims. The specific claims affected are not itemized in the provided information, but the statement "cancelling all challenged claims" indicates a broad impact.

Regarding estoppel, since IPR2019-01631 was dismissed before institution, no estoppel under 35 U.S.C. § 315(e)(2) would apply to Unified Patents or its privies for any grounds that could have been raised in that IPR. However, the ex parte reexamination initiated by Unified Patents demonstrates a successful strategy to challenge the patent's validity. This pattern signals that Unified Patents actively targeted this patent, and their persistence through reexamination ultimately yielded a favorable outcome for potential defendants.

Recommended next steps

If you are a defendant facing assertion of US Patent 7224678, the primary defensive step is to highlight the outcome of ex parte reexamination Control No. 90/015,188. The USPTO issued a Notice of Intent to Issue Reexamination Certificate on 2026-05-20, stating that "All claims maintained rejected." This effectively means the USPTO has found all challenged claims unpatentable.

You should access the official record for ex parte reexamination Control No. 90/015,188 via the USPTO Patent Center (patents.uspto.gov/patentcenter) or Public PAIR. This record will detail precisely which claims were challenged and subsequently cancelled. This outcome provides a very strong basis to argue non-infringement or invalidity for any asserted claims that were part of the reexamination.

The specific disposition to cite is the "Notice of Intent to Issue Reexamination Certificate" entered on 2026-05-20, which states: "Reexamination Certificate to Issue. All claims maintained rejected."

Inventors

• Thomas Jay Billhartz (employed by Harris Corp at the time of filing, as indicated by the immediate assignment of his interest to Harris Corp on the filing date).

Original assignee

• Harris Corp
• Shipped a product embodying the claims: Yes, it is highly probable that Harris Corp, a diversified technology company specializing in communications equipment, developed and shipped wireless network products that incorporated or could benefit from intrusion detection features described in the patent.
• Primary line of business: Information technology, telecommunications, government services, electronic systems.
• Current status: Acquired. Harris Corporation merged with L3 Technologies in 2019 to form L3Harris Technologies, Inc., which is currently an operating company.

Assignment timeline

• 2002-08-12 (executed) / recorded 2002-09-03 — Reel 013444/0839
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: BILLHARTZ, THOMAS JAY
  • Assignee: HARRIS CORPORATION
  • Correspondent: NOT PROVIDED
  • Context: Original assignment from inventor to the initial assignee.
• 2020-05-29 (executed) / recorded 2020-06-05 — Reel 052853/0153
  • Conveyance: PATENT SECURITY AGREEMENT
  • Assignor: ACACIA RESEARCH GROUP LLC, AMERICAN VEHICULAR SCIENCES LLC, BONUTTI SKELETAL INNOVATIONS LLC, CELLULAR COMMUNICATIONS EQUIPMENT LLC, INNOVATIVE DISPLAY TECHNOLOGIES LLC, LIFEPORT SCIENCES LLC, LIMESTONE MEMORY SYSTEMS LLC, MERTON ACQUISITION HOLDCO LLC, MOBILE ENHANCEMENT SOLUTIONS LLC, MONARCH NETWORKING SOLUTIONS LLC, NEXUS DISPLAY TECHNOLOGIES LLC, PARTHENON UNIFIED MEMORY ARCHITECTURE LLC, R2 SOLUTIONS LLC, SAINT LAWRENCE COMMUNICATIONS LLC, STINGRAY IP SOLUTIONS LLC, SUPER INTERCONNECT TECHNOLOGIES LLC, TELECONFERENCE SYSTEMS LLC, UNIFICATION TECHNOLOGIES LLC
  • Assignee: STARBOARD VALUE INTERMEDIATE FUND LP, AS COLLATERAL AGENT
  • Correspondent: ANDREW K. ROSZEL, ESQ., AKERMAN LLP, 777 S. FLAGLER DRIVE, SUITE 1100 WEST, WEST PALM BEACH, FL 33401. This correspondent recurs in this chain.
  • Context: Securitization event involving numerous Acacia-related entities granting a security interest.
• 2020-06-18 (executed) / recorded 2020-06-23 — Reel 053654/0254
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: EAGLE TECHNOLOGIES, INC., HARRIS GLOBAL COMMUNICATIONS, INC., L3HARRIS TECHNOLOGIES, INC.
  • Assignee: ACACIA RESEARCH GROUP LLC
  • Correspondent: SCOTT S. MARSHALL, LAW OFFICE OF SCOTT S. MARSHALL, P.C., 1801 RESEARCH BOULEVARD, SUITE 400, ROCKVILLE, MD 20850. This correspondent recurs in this chain.
  • Context: Transfer of patent from the original operating company's successor (L3Harris Technologies, Inc.) to a known patent assertion entity (Acacia Research Group LLC).
• 2020-06-18 (executed) / recorded 2020-06-23 — Reel 053654/0259
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: ACACIA RESEARCH GROUP LLC
  • Assignee: STINGRAY IP SOLUTIONS LLC
  • Correspondent: SCOTT S. MARSHALL, LAW OFFICE OF SCOTT S. MARSHALL, P.C., 1801 RESEARCH BOULEVARD, SUITE 400, ROCKVILLE, MD 20850. This correspondent recurs in this chain.
  • Context: Internal transfer within Acacia's network, to one of its specific patent assertion subsidiaries (Stingray IP Solutions LLC).
• 2020-07-02 (executed) / recorded 2020-07-08 — Reel 053787/0942
  • Conveyance: RELEASE OF SECURITY INTEREST IN PATENTS
  • Assignor: STARBOARD VALUE INTERMEDIATE FUND LP
  • Assignee: AMERICAN VEHICULAR SCIENCES LLC, CELLULAR COMMUNICATIONS EQUIPMENT LLC, R2 SOLUTIONS LLC, UNIFICATION TECHNOLOGIES LLC, STINGRAY IP SOLUTIONS LLC, SUPER INTERCONNECT TECHNOLOGIES LLC, ACACIA RESEARCH GROUP LLC, TELECONFERENCE SYSTEMS LLC, MOBILE ENHANCEMENT SOLUTIONS LLC, INNOVATIVE DISPLAY TECHNOLOGIES LLC, BONUTTI SKELETAL INNOVATIONS LLC, LIMESTONE MEMORY SYSTEMS LLC, LIFEPORT SCIENCES LLC, MONARCH NETWORKING SOLUTIONS LLC, PARTHENON UNIFIED MEMORY ARCHITECTURE LLC, NEXUS DISPLAY TECHNOLOGIES LLC, SAINT LAWRENCE COMMUNICATIONS LLC
  • Correspondent: ANDREW K. ROSZEL, ESQ., AKERMAN LLP, 777 S. FLAGLER DRIVE, SUITE 1100 WEST, WEST PALM BEACH, FL 33401. This correspondent recurs in this chain.
  • Context: Release of a previously granted security interest.
• 2021-11-09 (executed) / recorded 2021-11-11 — Reel 055866/0337
  • Conveyance: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNOR NAME PREVIOUSLY RECORDED ON REEL 052853 FRAME 0153. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY INTEREST GRANTED PURSUANT TO THE PATENT SECURITY AGREEMENT PREVIOUSLY RECORDED.
  • Assignor: STINGRAY IP SOLUTIONS LLC
  • Assignee: STARBOARD VALUE INTERMEDIATE FUND LP, AS COLLATERAL AGENT
  • Correspondent: ANDREW K. ROSZEL, ESQ., AKERMAN LLP, 777 S. FLAGLER DRIVE, SUITE 1100 WEST, WEST PALM BEACH, FL 33401. This correspondent recurs in this chain.
  • Context: Corrective assignment confirming a security interest previously granted.
• 2021-11-09 (executed) / recorded 2021-11-11 — Reel 055866/0342
  • Conveyance: CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE NAME PREVIOUSLY RECORDED ON REEL 053654 FRAME 0254. ASSIGNOR(S) HEREBY CONFIRMS THE RELEASE OF SECURITY INTEREST GRANTED PURSUANT TO THE PATENT SECURITY AGREEMENT PREVIOUSLY RECORDED.
  • Assignor: STARBOARD VALUE INTERMEDIATE FUND LP, AS COLLATERAL AGENT
  • Assignee: STINGRAY IP SOLUTIONS LLC
  • Correspondent: ANDREW K. ROSZEL, ESQ., AKERMAN LLP, 777 S. FLAGLER DRIVE, SUITE 1100 WEST, WEST PALM BEACH, FL 33401. This correspondent recurs in this chain.
  • Context: Corrective assignment confirming a release of security interest.

Timeline diagram

timeline
    title Ownership of US 7224678
    2002 : Filed by Harris Corp
    2007 : Patent Issued
    2020 : Securitization to Starboard
         : Assigned to Acacia Research Group
         : Assigned to Stingray IP Solutions
         : Security interest released
    2021 : Corrective assignment
         : Corrective release

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The patent was transferred to Stingray IP Solutions LLC (Reel 053654/0259, 2020-06-18), which is a subsidiary of Acacia Research Group LLC, known for patent licensing and assertion. Stingray IP Solutions LLC itself functions as a licensing-only entity.
2. Known asserter in the chain — Present. The patent was assigned to ACACIA RESEARCH GROUP LLC (Reel 053654/0254, 2020-06-18) and subsequently to STINGRAY IP SOLUTIONS LLC (Reel 053654/0259, 2020-06-18), both of which are publicly known patent assertion entities.
3. Repeat correspondent across the chain — Present.
   • SCOTT S. MARSHALL, LAW OFFICE OF SCOTT S. MARSHALL, P.C., appears on Reel 053654/0254 and 053654/0259, handling the transfers to Acacia and then to Stingray.
   • ANDREW K. ROSZEL, ESQ., AKERMAN LLP, appears on Reel 052853/0153, 053787/0942, 055866/0337, and 055866/0342 for the securitization and subsequent corrective filings.
4. Cascading transfers — Present. The assignments from L3Harris to Acacia Research Group LLC (Reel 053654/0254) and from Acacia Research Group LLC to Stingray IP Solutions LLC (Reel 053654/0259) were both executed on 2020-06-18 and recorded on 2020-06-23, showing consecutive transfers within a very short timeframe.
5. Pre-litigation transfer — Present. The transfers to Acacia Research Group LLC and Stingray IP Solutions LLC were executed on 2020-06-18 and recorded on 2020-06-23 (Reel 053654/0254, 053654/0259). This timing precedes numerous infringement suits filed in 2021 (e.g., cases 2:21-cv-00202, 2:21-cv-00196, etc.), falling within the 6-month window often indicative of pre-litigation transfers.
6. Bankruptcy fire-sale — Not present. Harris Corp merged with L3 Technologies; there is no indication of bankruptcy leading to the patent transfer.
7. Privateering — Unclear. While the patent was transferred from an operating company (L3Harris) to a known NPE (Acacia/Stingray), there is no explicit public evidence to determine if L3Harris retained a financial interest or directed the subsequent assertion campaigns.
8. Defensive aggregator (anti-NPE) — Not present. The ownership chain ends with Stingray IP Solutions LLC, an active patent assertion entity.

Verdict

NPE — high confidence

The assignment chain demonstrates multiple strong indicators of NPE activity, including the transfer from an operating company (L3Harris) to a known patent assertion entity (Acacia Research Group LLC and its subsidiary Stingray IP Solutions LLC) via cascading transfers on 2020-06-18 (Reel 053654/0254, 053654/0259). These transfers occurred immediately prior to a flurry of litigation commencing in 2021, and the consistent use of specific correspondents in the chain further reinforces this conclusion.

For verification, see the USPTO Assignment Center: https://assignmentcenter.uspto.gov/

To identify the most relevant prior art for US Patent 7224678, we will examine the patent citations listed on the patent's Google Patents page. These are the documents cited by the examiner or applicant during the patent's prosecution. The focus will be on documents that most directly disclose the inventive concepts of US7224678, particularly its independent claims related to wireless network intrusion detection using MAC layer anomalies.

The most strikingly relevant prior art identified from the patent citations is WO0137532A2, due to its identical inventor, assignee, and abstract content, coupled with an earlier publication date.

1. WO0137532A2 - Wireless network having intrusion detection and related methods

• Full Citation: WO0137532A2 (Billhartz, Thomas Jay; Harris Corp.)

• Publication/Filing Date:

  • Publication Date: 2001-05-25
  • Filing Date: 2000-11-15

• Brief Description: This international patent application describes a wireless network system and method for detecting intrusions. It features a policing station that monitors transmissions among stations to detect various anomalies at the Media Access Control (MAC) layer. Specifically, it discloses detecting Frame Check Sequence (FCS) errors from a MAC address, failed attempts to authenticate MAC addresses, illegal Network Allocation Vector (NAV) values in RTS/CTS packets, and contention-free mode operation outside of a Contention-Free Period (CFP) (or contention mode operation during a CFP). Upon detection of these anomalies, an intrusion alert is generated.

• Potential Anticipation (35 U.S.C. § 102): This document appears to directly anticipate all independent claims of US7224678 (Claims 1, 12, 22, 30, 36, 42, 51, 59, 65, 69). The abstract of WO0137532A2 contains language virtually identical to the abstract and summary of US7224678, explicitly disclosing the core elements of each independent claim:

  • Claim 1 (System - FCS Errors): "monitoring transmissions among the plurality of stations to detect frame check sequence (FCS) errors from a MAC address, and generating an intrusion alert based upon detecting a number of FCS errors for the MAC address exceeding a threshold."
  • Claim 12 (System - Failed Authentications): "detect intrusions by monitoring transmissions among the plurality of stations to detect failed attempts to authenticate MAC addresses, and generating an intrusion alert based upon detecting a number of failed attempts to authenticate a MAC address."
  • Claim 22 (System - Illegal NAV Values): "detect intrusions by monitoring RTS and CTS packets sent between the plurality of stations to detect an illegal NAV value therein and generate an intrusion alert based thereon."
  • Claim 30 (System - Contention-Free Mode outside CFP): "detect intrusions by monitoring transmissions among the plurality of stations to detect contention-free mode operation outside of a CFP."
  • Claim 36 (System - Contention Mode during CFP): "(or vice versa) and generate an intrusion alert based thereon," covering contention mode during CFP.
  • Claims 42, 51, 59, 65, 69 (Method Claims): The method aspects corresponding to the system claims are implicitly and directly described by the detection and alert generation steps outlined for each anomaly.

  Since WO0137532A2 was published on 2001-05-25, which is prior to the filing date of US7224678 (2002-08-12), and US7224678 does not claim priority back to WO0137532A2, this document constitutes strong prior art.

2. US6526053B1 - Method and system for managing wireless local area network security

• Full Citation: US6526053B1 (Ramaswamy et al.)
• Publication/Filing Date:
  • Publication Date: 2003-02-25
  • Filing Date: 1999-08-30
• Brief Description: This patent describes a system and method for managing wireless local area network (WLAN) security using a centralized security server (CSS). The CSS queries wireless access points (APs) for client event logs and configuration information, storing it in a database. It analyzes these logs to identify abnormal events, such as unauthorized MAC addresses, multiple clients using the same MAC address, or clients roaming outside authorized areas. Upon detection, an alert is generated, and actions like client de-authentication or disconnection may be taken.
• Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant, particularly for claims related to MAC address monitoring:
  • Claim 12 (System - Failed Authentications) & Claim 51 (Method - Failed Authentications): The abstract's mention of identifying "unauthorized MAC addresses" and taking actions like "de-authenticating or disconnecting the client" suggests a detection of unauthorized or failed MAC address authentications, closely aligning with these claims.
  • Related to FIG. 10 / Method Block 202 (Collisions of same MAC address): The explicit disclosure of detecting "multiple clients using the same MAC address" directly anticipates the concept of detecting collisions of a same MAC address, which is a specific intrusion detection feature described in detail in the specification of US7224678 (e.g., FIG. 10 and related description). While this specific feature is not an independent claim, it's a key disclosed embodiment.

3. IEEE 802.11 Standard, 1999 Edition

• Full Citation: "IEEE Standards for Information Technology—Telecommunications and Information Systems—Local and Metropolitan Area Network—Specific Requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications," 1999 Edition.
• Publication/Filing Date: 1999.
• Brief Description: This is a foundational industry standard defining the protocols for wireless local area networks. It specifies various MAC layer elements, including frame check sequences (FCS), MAC addresses, Request To Send (RTS)/Clear To Send (CTS) packets, Network Allocation Vectors (NAV), contention and contention-free periods (CFP), and the Wired Equivalent Privacy (WEP) algorithm. US7224678 incorporates this standard by reference.
• Potential Anticipation (35 U.S.C. § 102): The IEEE 802.11 standard itself does not directly anticipate the intrusion detection methods claimed in US7224678. Instead, it provides the technical framework and defines the mechanisms (e.g., FCS, NAV, contention modes) that US7224678's invention monitors for anomalies to detect intrusions. The background of US7224678 explicitly states that "While the WEP algorithm does provide some measure of network security, it does not detect or report potential intrusions into the network." Therefore, while essential background, it would not anticipate the novel intrusion detection logic under 35 U.S.C. § 102, but rather would be crucial for a 35 U.S.C. § 103 (obviousness) analysis.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 7224678

An invention is considered obvious under 35 U.S.C. § 103 if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (POSA). This analysis considers the scope and content of the prior art, the differences between the prior art and the claims, the level of ordinary skill in the art, and any secondary considerations of non-obviousness.

For US Patent 7224678, the filing date is 2002-08-12. A person having ordinary skill in the art in this field would have had a strong understanding of wireless local and metropolitan area networks, particularly the IEEE 802.11 standard, and common network security principles.

Prior Art Combinations and Motivations for Obviousness

The prior art identified, particularly WO0137532A2, is remarkably similar to US7224678. The "Prior Art" section notes that WO0137532A2, with an earlier publication date (2001-05-25) and identical inventor and assignee, "appears to directly anticipate all independent claims of US7224678." If this is the case, the claims would be invalid under 35 U.S.C. § 102 (anticipation), which inherently also renders them obvious. However, even if not fully anticipated, the claims would be rendered obvious by combining WO0137532A2 with other foundational prior art, such as the IEEE 802.11 Standard.

Primary Combination: WO0137532A2 and IEEE 802.11 Standard, 1999 Edition

References:

• WO0137532A2 - Wireless network having intrusion detection and related methods (Billhartz, Thomas Jay; Harris Corp.)
• IEEE 802.11 Standard, 1999 Edition - "IEEE Standards for Information Technology—Telecommunications and Information Systems—Local and Metropolitan Area Network—Specific Requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications"

Motivation to Combine:
A person having ordinary skill in the art (POSA) designing or implementing a wireless intrusion detection system, as described in WO0137532A2, would naturally and necessarily refer to the underlying technical specifications for wireless networks. The IEEE 802.11 Standard is explicitly acknowledged in US7224678 as a foundational document for wireless LAN/MAN protocols, defining the Media Access Control (MAC) layer and Physical Layer (PHY) specifications upon which the claimed invention operates. The intrusion detection methods in both WO0137532A2 and US7224678 rely on monitoring MAC layer anomalies, such as FCS errors, NAV values in RTS/CTS packets, and contention modes. To effectively monitor and interpret these MAC layer elements for intrusion detection, a POSA would directly consult the IEEE 802.11 Standard, which provides the precise definitions, formats, and operational rules for these elements. The motivation is to apply the conceptual intrusion detection techniques described in WO0137532A2 to the practical and standardized framework of an 802.11 wireless network.

Analysis of Independent Claims:

1. Claims 1 and 42 (System and Method for FCS Errors):

   • WO0137532A2 explicitly discloses "monitoring transmissions among the plurality of stations to detect frame check sequence (FCS) errors from a MAC address, and generating an intrusion alert based upon detecting a number of FCS errors for the MAC address exceeding a threshold."
   • A POSA would combine this teaching with the IEEE 802.11 Standard's definition of a Frame Check Sequence (FCS) and MAC addresses within an 802.11 frame, and the standard's mechanism for error detection. The standard provides the necessary details for implementing the FCS error detection taught by WO0137532A2.

2. Claims 12 and 51 (System and Method for Failed Authentications):

   • WO0137532A2 discloses detecting "failed attempts to authenticate MAC addresses, and generating an intrusion alert based upon detecting a number of failed attempts to authenticate a MAC address."
   • The IEEE 802.11 Standard defines the authentication procedures and the use of MAC addresses in wireless networks. A POSA would naturally apply the intrusion detection concept from WO0137532A2 using the specific authentication protocols and MAC address handling detailed in the 802.11 standard.

3. Claims 22 and 59 (System and Method for Illegal NAV Values):

   • WO0137532A2 teaches detecting "illegal NAV value[s] therein and generate an intrusion alert based thereon" by monitoring RTS and CTS packets.
   • The IEEE 802.11 Standard defines the Request To Send (RTS) and Clear To Send (CTS) packets and the Network Allocation Vector (NAV) within them, including their purpose and expected values. A POSA implementing the detection of "illegal" NAV values would necessarily refer to the 802.11 Standard to understand what constitutes a "legal" or permissible NAV value and therefore detect deviations.

4. Claims 30 and 65 (System and Method for Contention-Free Mode Operation Outside CFP):

   • WO0137532A2 describes detecting "contention-free mode operation outside of a CFP" for intrusion detection.
   • The IEEE 802.11 Standard clearly defines "contention-free mode" and "Contention-Free Periods (CFPs)" as operational modes for wireless stations. A POSA would combine these references to monitor for instances where a station operates in a mode that contradicts the network's established CFP schedule, as defined by the standard.

5. Claims 36 and 69 (System and Method for Contention Mode Operation During CFP):

   • WO0137532A2's disclosure of detecting "contention-free mode operation outside of a CFP (or vice versa)" covers detecting contention mode operation during a CFP.
   • As with the previous point, the IEEE 802.11 Standard explicitly defines "contention mode" and "CFPs." A POSA would use the standard's definitions to identify and flag contention mode activity during a period designated for contention-free operation, based on the intrusion detection principle taught by WO0137532A2.

Secondary Combination: US6526053B1 and IEEE 802.11 Standard, 1999 Edition

References:

• US6526053B1 - Method and system for managing wireless local area network security (Ramaswamy et al.)
• IEEE 802.11 Standard, 1999 Edition

Motivation to Combine:
US6526053B1 teaches a system for managing WLAN security by monitoring client event logs and configuration information to identify abnormal events, such as "unauthorized MAC addresses" and "multiple clients using the same MAC address". A POSA concerned with enhancing wireless network security, as addressed by US6526053B1, would be motivated to leverage the detailed MAC layer protocols defined in the IEEE 802.11 Standard. The motivation is to implement the general security monitoring taught by US6526053B1 by drawing upon the specific technical mechanisms of an 802.11 network.

Analysis of Relevant Aspects (e.g., Failed Authentications, MAC Address Collisions):

• Claims 12 and 51 (Failed Authentications): US6526053B1's concept of identifying "unauthorized MAC addresses" and de-authenticating clients directly implies monitoring authentication attempts. A POSA would find it obvious to apply this monitoring to detect failed authentication attempts, using the 802.11 standard's authentication process. This combination would lead to the generation of an alert upon detecting a threshold number of such failures, an obvious design choice for a security system.
• Disclosed Embodiments (e.g., FIG. 10 / Method Block 202 for Collisions of same MAC address): US6526053B1 explicitly teaches detecting "multiple clients using the same MAC address" as an abnormal event for security management. This directly addresses the concept of detecting collisions of a same MAC address as described in US7224678. The IEEE 802.11 Standard defines how MAC addresses are used in the network, providing the context for detecting such collisions.

Conclusion

Given the comprehensive disclosure in WO0137532A2, which largely mirrors the independent claims of US7224678, in combination with the foundational teachings of the IEEE 802.11 Standard, all independent claims (1, 12, 22, 30, 36, 42, 51, 59, 65, 69) of US7224678 would have been obvious to a person having ordinary skill in the art at the time of the invention. The motivation for combining these references is clear: to apply known intrusion detection principles (from WO0137532A2 and general network security as exemplified by US6526053B1) to the specific, standardized operational framework of IEEE 802.11 wireless networks.