US 7193986

Summary of U.S. Patent 7,193,986

Title: Wireless network medium access control protocol

Assignee: Arlington Technologies, LLC (current) / Nortel Networks Ltd. (at time of issue)

Inventors: William Giles Scanlon, Tze-Yeung Chui

Filing Date: May 30, 2002

Issue Date: March 20, 2007

Abstract:
A device for use in a packet-oriented transmission network comprises a transmitter arranged to transmit a sequence comprising at least one data packet and a receiver arranged to receive a sequence comprising at least one data packet. At least one data packet in one of the transmitted or received sequence of data packets includes at least one pointer to indicate when a designated data packet in the sequence is to be received and/or transmitted. The designated data packet includes an indication of at least one other device connected to the packet-oriented transmission network.

Plain-Language Overview of Independent Claims:

This patent introduces a method for managing communication in a wireless network that has one central "master" device (like a Wi-Fi router) and several "slave" devices (like laptops or smartphones). The core innovation is the use of "pointers" within data packets to improve efficiency and reduce power consumption for the slave devices.

Claim 1 describes the master device. In simple terms, this claim outlines a master device that sends out data packets in a timed sequence. Crucially, some of these packets contain a pointer that tells all listening devices when a special "designated packet" will be sent. This designated packet acts as a schedule, informing each participating slave device exactly when it is their turn to transmit information back to the master. This system allows slave devices to power down their receivers and save battery life, only waking up when they expect to receive the designated packet or their own specific data.

Claim 9 describes the slave device. This claim mirrors the master device's operation but from the perspective of a user's device. It details a slave device that is capable of receiving the data packets sent by the master. The slave device can read the pointer in these packets to know when to expect the important "designated packet." By reading this designated packet, the slave device learns which other devices are on the network and, most importantly, when it has been scheduled to send its own data. This allows the slave device to coordinate its transmissions and remain in a low-power "sleep" mode for much of the time, significantly extending its battery life.

Litigation and Reexamination:

As of April 2026, U.S. Patent 7,193,986 has been the subject of litigation and a USPTO ex parte reexamination. The patent is currently assigned to Arlington Technologies, LLC, which has asserted it in lawsuits against companies including T-Mobile. A search of the Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 did not reveal an active appeal directly associated with this patent number, though district court litigation was initiated in 2025 (Case 2:25-cv-00279 in the Eastern District of Texas). Furthermore, in an ex parte reexamination proceeding, the USPTO has indicated its intent to issue a reexamination certificate that would cancel several of the patent's claims, including independent claim 1. This could significantly impact the patent's enforceability. I do not have authoritative information on the final outcome of the reexamination or any ongoing appeals.

Known Litigation for U.S. Patent 7,193,986

As of April 30, 2026, U.S. Patent 7,193,986, currently assigned to Arlington Technologies, LLC, has been asserted in the following district court cases:

1. Arlington Technologies LLC v. T-Mobile US, Inc. et al.

• Plaintiff: Arlington Technologies, LLC
• Defendants: T-Mobile US, Inc., T-Mobile USA, Inc., Sprint LLC, Sprint Solutions LLC, Sprint Spectrum LLC.
• Jurisdiction: U.S. District Court for the Eastern District of Texas
• Case Number: 2:25-cv-00279
• Filing Date: March 7, 2025
• Status: The case is ongoing. It has been assigned to Judge Rodney Gilstrap. The complaint alleges that various T-Mobile and Sprint products, including gateways, routers, and mesh access points that support the 802.11ax Wi-Fi standard, infringe on the '986 patent among others. This case followed a notice of settlement in a prior lawsuit filed by Arlington Technologies against Comcast.

2. Arlington Technologies LLC v. Comcast Cable Communications, LLC

• Plaintiff: Arlington Technologies, LLC
• Defendant: Comcast Cable Communications, LLC
• Jurisdiction: U.S. District Court for the Eastern District of Texas
• Case Number: Information on the specific case number for the Comcast litigation was not immediately available in the searched materials, but it is referenced as preceding the T-Mobile case.
• Filing Date: September 2024.
• Outcome: Settled. This litigation was the first initiated by Arlington Technologies after acquiring a large portfolio of former Avaya patents. The '986 patent was asserted against Comcast products that are wireless access points configured to support 802.11ax.

Additionally, the patent is subject to an ex parte reexamination filed by Unified Patents on July 28, 2025. On April 3, 2026, the USPTO's Central Reexamination Unit (CRU) issued a notice of intent to issue a reexamination certificate that would cancel claims 1-3, 5-6, and 8-9, which could render the patent invalid for enforcement purposes.

Proceedings Overview

There are no Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) trial proceedings on file with the Patent Trial and Appeal Board (PTAB) for U.S. Patent 7,193,986 based on available data. Therefore, the patent has not been subjected to the types of AIA trial proceedings that would result in claims being upheld or invalidated by the PTAB.

However, it is critical to note that the patent is undergoing an ex parte reexamination (not an AIA trial proceeding). In this reexamination, the USPTO has indicated its intent to cancel several claims, including the independent claims. This development significantly impacts the patent's enforceability.

Ex Parte Reexamination of U.S. Patent 7,193,986

• Type: Ex Parte Reexamination
• Filed: July 28, 2025 (by Unified Patents)
• Status: Notice of Intent to Issue Reexamination Certificate issued, indicating claims 1-3, 5-6, and 8-9 are to be canceled.
• Petition grounds: The ex parte reexamination was initiated by Unified Patents, presumably on grounds of unpatentability under 35 U.S.C. §§ 102 and/or 103 based on prior art. While specific art and detailed reasoning are typically found in the reexamination file, the prior art analysis conducted previously for this patent (referencing U.S. 6,795,418 B2, U.S. 6,088,337 A, U.S. 6,498,936 B1, U.S. 6,947,446 B2, and US 2002/0115458 A1) suggests potential grounds for cancellation.
• Intent to Issue Reexamination Certificate: On April 3, 2026, the USPTO's Central Reexamination Unit (CRU) issued a notice of its intent to issue a reexamination certificate that would cancel claims 1-3, 5-6, and 8-9.
• Defensive value: This is a highly significant development. If the reexamination certificate is issued as intended, independent claims 1 and 9, along with several dependent claims, will be canceled. Any infringement theory relying on these claims would be significantly weakened, if not entirely eliminated. This provides a strong defensive posture against assertion of the patent, particularly for claims 1-3, 5-6, and 8-9.

Strategic Summary

As of May 29, 2026, U.S. Patent 7,193,986 has no formal AIA trial proceedings (IPR, PGR, CBM) on record with the PTAB. Therefore, none of its claims have been formally challenged or sustained through these specific mechanisms.

However, the patent has undergone an ex parte reexamination, which is a different form of USPTO administrative review. In this proceeding, the USPTO has issued an intent to cancel claims 1-3, 5-6, and 8-9. This means that independent claims 1 and 9 are slated for cancellation, along with several dependent claims (2, 3, 5, 6, 8). The claims currently sustained by this reexamination (i.e., not indicated for cancellation) would be claim 4 and claim 7. All other claims, if any, remain untested by this specific proceeding. This outcome substantially narrows the scope of the patent, potentially rendering it unassertable on its broadest claims.

The estoppel landscape regarding AIA trials is not applicable, as no IPR, PGR, or CBM proceedings have taken place. However, the reexamination by Unified Patents indicates an active defensive strategy against this patent. Given the USPTO's intent to cancel the broad claims, it signals that the patent owner's ability to assert these claims in litigation is severely compromised.

Recommended Next Steps

• For a defendant facing assertion of this patent: Immediately confirm the final status of the ex parte reexamination for U.S. Patent 7,193,986. If the reexamination certificate has indeed issued, formally canceling claims 1-3, 5-6, and 8-9, any infringement allegations based on these claims are likely without merit. This outcome should be leveraged forcefully in defense, potentially through motions to dismiss or for summary judgment.
• Monitor the reexamination docket: Access the official docket for the ex parte reexamination (likely 90/016,xxx or similar, which should be available through the USPTO's Patent Center or Unified Patents' portal) to obtain the final reexamination certificate once it issues.
• Review surviving claims: Conduct a thorough analysis of the remaining claims (claims 4 and 7 as currently understood) to determine their scope and if any current or planned product functionality could still potentially infringe them.
• Absence of AIA trials: The lack of IPR, PGR, or CBM proceedings suggests that, for a defendant, the option of filing such a petition might still be available, particularly for any claims that were not targeted or canceled in the ex parte reexamination. However, given the ex parte reexamination's outcome, such a strategy might be unnecessary for the canceled claims and should be carefully weighed for the surviving claims against the patent's approaching expiration date (May 25, 2025).

Inventors

• William Giles Scanlon (Nortel Networks Ltd.)
• Tze-Yeung Chui (Nortel Networks Ltd.)

Both inventors were employed by Nortel Networks Ltd. at the time of filing. There is no unusual pattern of inventors departing the original assignee within 12 months of filing based on the provided information.

Original assignee

The entity named on the issued patent was Nortel Networks Ltd. Nortel Networks was a multinational telecommunications and data networking equipment manufacturer. While the patent itself does not explicitly state that Nortel Networks Ltd. shipped a product embodying these specific claims, Nortel was a significant player in telecommunications, and the patent's description compares its invention to Bluetooth, a widely used wireless standard, suggesting application in their product lines. Nortel Networks Ltd. filed for bankruptcy protection in 2009.

Assignment timeline

• 2002-05-07 (executed) / recorded 2002-05-30 — Reel 012947/0928

  • Conveyance: Assignment
  • Assignor: William Giles Scanlon, Tze-Yeung Chui
  • Assignee: Nortel Networks Limited, Canada
  • Correspondent: Not specified in the record.
  • Context: Original assignment from inventors to company.

• 2010-01-29 (executed) / recorded 2010-02-04 — Reel 023892/0500

  • Conveyance: Security Agreement
  • Assignor: Avaya Inc.
  • Assignee: Citibank, N.A., as Administrative Agent, New York
  • Correspondent: Jeffrey B. Fromm, Bingham McCutchen LLP, New York, N.Y.
  • Context: Securitization of assets by Avaya Inc.

• 2010-01-29 (executed) / recorded 2010-02-05 — Reel 023905/0001

  • Conveyance: Security Agreement
  • Assignor: Avaya Inc.
  • Assignee: Citicorp USA, Inc., as Administrative Agent, New York
  • Correspondent: Jeffrey B. Fromm, Bingham McCutchen LLP, New York, N.Y. (This correspondent recurs in this chain.)
  • Context: Securitization of assets by Avaya Inc.

• 2009-12-18 (executed) / recorded 2010-02-26 — Reel 023998/0878

  • Conveyance: Assignment
  • Assignor: Nortel Networks Limited
  • Assignee: Avaya Inc., New Jersey
  • Correspondent: Jonathan K. Waldrop, Gardner, Groff, Greenwald & Villaneuva, P.C., Atlanta, GA
  • Context: Acquisition of assets from Nortel Networks Limited (likely part of bankruptcy asset sales).

• 2011-02-11 (executed) / recorded 2011-02-22 — Reel 025863/0535

  • Conveyance: Security Agreement
  • Assignor: Avaya Inc., a Delaware Corporation
  • Assignee: The Bank of New York Mellon Trust, NA, as Notes Collateral Agent, Pennsylvania
  • Correspondent: Mark J. Ehlert, Esq., Bingham McCutchen LLP, New York, N.Y.
  • Context: Securitization of assets by Avaya Inc.

• 2013-03-07 (executed) / recorded 2013-03-13 — Reel 030083/0639

  • Conveyance: Security Agreement
  • Assignor: Avaya, Inc.
  • Assignee: The Bank of New York Mellon Trust Company, N.A., Pennsylvania
  • Correspondent: Joseph L. Young, Esq., Bingham McCutchen LLP, New York, NY
  • Context: Securitization of assets by Avaya Inc.

• 2017-01-24 (executed) / recorded 2017-01-27 — Reel 041576/0001

  • Conveyance: Security Interest
  • Assignor: Avaya Inc.; Avaya Integrated Cabinet Solutions Inc.; Octel Communications Corporation; and others
  • Assignee: Citibank, N.A., as Administrative Agent, New York
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY
  • Context: Securitization of assets by Avaya entities.

• 2017-11-28 (executed) / recorded 2017-12-15 — Reel 044891/0564

  • Conveyance: Bankruptcy Court Order Releasing All Liens
  • Assignor: Citibank, N.A.
  • Assignee: Avaya Inc., California
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of security interest due to Avaya's bankruptcy proceedings.

• 2017-11-28 (executed) / recorded 2017-12-15 — Reel 044892/0001

  • Conveyance: Bankruptcy Court Order Releasing All Liens
  • Assignor: The Bank of New York Mellon Trust, NA
  • Assignee: Avaya Inc., California
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of security interest due to Avaya's bankruptcy proceedings.

• 2017-11-28 (executed) / recorded 2017-12-15 — Reel 044893/0531

  • Conveyance: Bankruptcy Court Order Releasing All Liens
  • Assignor: Citibank, N.A.
  • Assignee: Octel Communications LLC (formerly known as Octel Communications Corporation), California; Avaya Integrated Cabinet Solutions Inc., California
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of security interest due to Avaya's bankruptcy proceedings.

• 2018-01-08 (executed) / recorded 2018-01-10 — Reel 045034/0001

  • Conveyance: Security Interest
  • Assignor: Avaya Inc., Avaya Integrated Cabinet Solutions LLC, Octel Communications LLC, VPNet Technologies, Inc., Zang, Inc.
  • Assignee: Goldman Sachs Bank USA, as Collateral Agent
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Securitization of Avaya assets post-bankruptcy emergence.

• 2018-01-08 (executed) / recorded 2018-01-11 — Reel 045052/0971

  • Conveyance: Release of Security Interest
  • Assignor: Citicorp USA, Inc.
  • Assignee: Sierra Holdings Corp., Avaya, Inc.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of a prior security interest.

• 2018-01-22 (executed) / recorded 2018-01-23 — Reel 045124/0026

  • Conveyance: Security Interest
  • Assignor: Avaya Inc., Avaya Integrated Cabinet Solutions LLC, Octel Communications LLC, VPNet Technologies, Inc., Zang, Inc.
  • Assignee: Citibank, N.A., as Collateral Agent
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Further securitization of Avaya assets.

• 2020-09-24 (executed) / recorded 2020-09-25 — Reel 053955/0436

  • Conveyance: Security Interest
  • Assignor: Avaya Inc., Avaya Integrated Cabinet Solutions LLC, Avaya Management L.P., Intellisist, Inc.
  • Assignee: Wilmington Trust, National Association
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Securitization of Avaya assets.

• 2022-08-03 (executed) / recorded 2022-08-05 — Reel 058774/0979

  • Conveyance: Intellectual Property Security Agreement
  • Assignor: Avaya Cabinet Solutions LLC, Avaya Inc., Avaya Management L.P., Intellisist, Inc.
  • Assignee: Wilmington Trust, National Association, as Collateral Agent
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Securitization of Avaya assets.

• 2023-04-20 (executed) / recorded 2023-04-26 — Reel 060938/0342

  • Conveyance: Release of Security Interest in Patents
  • Assignor: Citibank, N.A., as Collateral Agent
  • Assignee: Avaya Inc., Avaya Management L.P., Avaya Integrated Cabinet Solutions LLC, Avaya Holdings Corp.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of a prior security interest.

• 2023-05-02 (executed) / recorded 2023-05-03 — Reel 061081/0376

  • Conveyance: Intellectual Property Security Agreement
  • Assignor: Avaya Inc., Avaya Management L.P., Intellisist, Inc., Knoahsoft Inc.
  • Assignee: Wilmington Savings Fund Society, FSB [Collateral Agent]
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Securitization of Avaya assets.

• 2023-05-03 (executed) / recorded 2023-05-04 — Reel 061087/0386

  • Conveyance: Intellectual Property Security Agreement
  • Assignor: Avaya Inc., Avaya Management L.P., Intellisist, Inc.
  • Assignee: Citibank, N.A., as Collateral Agent
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Securitization of Avaya assets.

• 2023-05-18 (executed) / recorded 2023-05-18 — Reel 061324/0273

  • Conveyance: Release of Security Interest in Patents
  • Assignor: Wilmington Trust, National Association, as Notes Collateral Agent
  • Assignee: Avaya Management L.P., Avaya Inc., Avaya Integrated Cabinet Solutions LLC, Intellisist, Inc.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of a prior security interest.

• 2023-05-18 (executed) / recorded 2023-05-18 — Reel 061324/0273

  • Conveyance: Release of Security Interest in Patents
  • Assignor: Wilmington Trust, National Association, as Notes Collateral Agent
  • Assignee: Intellisist, Inc., Avaya Management L.P., Avaya Inc., Avaya Integrated Cabinet Solutions LLC
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of a prior security interest.

• 2023-05-18 (executed) / recorded 2023-05-18 — Reel 061324/0273

  • Conveyance: Release of Security Interest in Patents
  • Assignor: Goldman Sachs Bank USA., as Collateral Agent
  • Assignee: Octel Communications LLC, Hyperquality II, LLC, Hyperquality, Inc., Avaya Integrated Cabinet Solutions LLC, Avaya Management L.P., CAAS Technologies, LLC, Intellisist, Inc., VPNet Technologies, Inc., Zang, Inc. (former name of Avaya Cloud Inc.), Avaya Inc.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release of a prior security interest.

• 2023-09-18 (executed) / recorded 2023-09-21 — Reel 061986/0268

  • Conveyance: Grantor's Name Change (Security Interest)
  • Assignor: Avaya Inc.
  • Assignee: Avaya LLC
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Corporate name change from Avaya Inc. to Avaya LLC for security interest purposes.

• 2024-03-21 (executed) / recorded 2024-03-25 — Reel 062752/0064

  • Conveyance: Intellectual Property Release and Reassignment
  • Assignor: Citibank, N.A.
  • Assignee: Avaya LLC, Avaya Management L.P.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release and reassignment of intellectual property.

• 2024-03-21 (executed) / recorded 2024-03-25 — Reel 062752/0073

  • Conveyance: Intellectual Property Release and Reassignment
  • Assignor: Wilmington Savings Fund Society, FSB
  • Assignee: Avaya LLC, Avaya Management L.P.
  • Correspondent: George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP, New York, NY (This correspondent recurs in this chain.)
  • Context: Release and reassignment of intellectual property.

• 2024-03-25 (executed) / recorded 2024-04-04 — Reel 062837/0342

  • Conveyance: Assignment of Assignors Interest
  • Assignor: Avaya LLC
  • Assignee: Arlington Technologies, LLC
  • Correspondent: Not specified in the record.
  • Context: Transfer of patent ownership from Avaya LLC to Arlington Technologies, LLC.

Timeline diagram

timeline
    title Ownership of US 7193986
    2002 : Inventors to Nortel Networks
    2009 : Nortel bankruptcy
    2010 : Avaya acquires from Nortel
         : Avaya securitizes with Citibank
         : Avaya securitizes with Citicorp
    2011 : Avaya securitizes with BNY Mellon
    2013 : Avaya securitizes with BNY Mellon
    2017 : Avaya securitizes with Citibank
         : Liens released for Avaya bankruptcy
    2018 : Avaya securitizes with Goldman Sachs
         : Citicorp releases security
         : Avaya securitizes with Citibank
    2020 : Avaya securitizes with Wilmington Trust
    2022 : Avaya securitizes with Wilmington Trust
    2023 : Citibank releases security
         : Avaya securitizes with Wilmington Savings
         : Avaya securitizes with Citibank
         : Wilmington Trust releases security
         : Goldman Sachs releases security
    2024 : Avaya Inc becomes Avaya LLC
         : Citibank releases IP to Avaya LLC
         : Wilmington releases IP to Avaya LLC
         : Avaya LLC to Arlington Technologies
    2025 : Patent expires May 25
         : Litigation filed
         : Reexamination initiated
    2026 : NIEIC issued

NPE / troll-pattern signals

1. Shell-entity transfer — Present.

   • The transfer from Avaya LLC to Arlington Technologies, LLC on 2024-03-25 (executed) / 2024-04-04 (recorded) (Reel 062837/0342) is a strong signal. Arlington Technologies, LLC is the current assignee. The prior litigation summary indicates Arlington Technologies LLC is a plaintiff in infringement lawsuits and acquired a large portfolio of former Avaya patents, suggesting a licensing-only business model.

2. Known asserter in the chain — Present.

   • Arlington Technologies, LLC is identified as a known asserter in the litigation summary, having filed lawsuits against T-Mobile and Comcast. This is confirmed by the assignment to Arlington Technologies, LLC on 2024-03-25 / 2024-04-04 (Reel 062837/0342).

3. Repeat correspondent across the chain — Present.

   • Jeffrey B. Fromm, Bingham McCutchen LLP appears as correspondent for Avaya's security agreements on 2010-02-04 (Reel 023892/0500) and 2010-02-05 (Reel 023905/0001).
   • George T. Williams, Esq., Milbank, Tweed, Hadley & McCloy LLP appears repeatedly for Avaya's security interests and releases from 2017-01-27 (Reel 041576/0001) through 2024-03-25 (Reel 062752/0073). This individual handled a significant portion of Avaya's assignments and releases leading up to the transfer to Arlington Technologies. The final transfer to Arlington Technologies, however, does not list a correspondent.

4. Cascading transfers — Not present.

   • While there are many security interests and releases, these are not direct ownership transfers between chained LLCs in quick succession. The primary ownership transfers are from Nortel to Avaya, and then from Avaya to Arlington, with a significant time gap between them.

5. Pre-litigation transfer — Present.

   • The patent was assigned to Arlington Technologies, LLC on 2024-03-25 (executed) / 2024-04-04 (recorded) (Reel 062837/0342).
   • The first lawsuit by Arlington Technologies against Comcast was filed in September 2024, and against T-Mobile on March 7, 2025 (Case 2:25-cv-00279).
   • The transfer date to Arlington Technologies is less than 6 months before the Comcast suit and less than a year before the T-Mobile suit, indicating the acquisition was likely made with the intent to assert.

6. Bankruptcy fire-sale — Present.

   • Nortel Networks Ltd., the original assignee, filed for bankruptcy. The assignment from Nortel Networks Limited to Avaya Inc. (2009-12-18 / 2010-02-26, Reel 023998/0878) occurred after Nortel's bankruptcy filing, indicating a fire-sale of assets.
   • Avaya Inc. also underwent bankruptcy, with multiple releases of liens "due to Avaya's bankruptcy proceedings" in December 2017 (Reel 044891/0564, Reel 044892/0001, Reel 044893/0531), leading to a subsequent series of securitizations and eventual sale of the patent to Arlington Technologies.

7. Privateering — Unclear.

   • While Avaya was an operating company that sold its patents to Arlington, there is no explicit information provided in the patent text or derived from Google Patents that Avaya is directly backing Arlington's assertion campaigns against its competitors. It's a common pattern for NPEs to acquire patents from operating companies, but the specific "privateering" arrangement is not evidenced.

8. Defensive aggregator (anti-NPE) — Not present.

   • The chain terminates with Arlington Technologies, LLC, which is an asserting entity, not a defensive aggregator.

Verdict

NPE — high confidence

This verdict is supported by multiple strong signals. The patent was transferred to Arlington Technologies, LLC (Reel 062837/0342), which is identified as a known patent asserter actively engaged in litigation against T-Mobile and Comcast, following a pre-litigation transfer within six months of the first lawsuit. Furthermore, the patent originated from Nortel Networks Ltd., which went through bankruptcy, leading to an asset sale (Reel 023998/0878), and Avaya Inc., an intermediate owner, also underwent bankruptcy, a common source for patent portfolios acquired by NPEs for assertion. The recurrence of a single correspondent attorney (George T. Williams, Esq.) across numerous Avaya assignments prior to the final sale further strengthens this conclusion.

USPTO Patent Assignment Search for US7193986

Analysis of Prior Art for U.S. Patent 7,193,986

This analysis covers the prior art references cited by the USPTO examiner during the original prosecution of U.S. Patent 7,193,986. The core of the invention in the '986 patent, particularly in independent claims 1 and 9, is a master-slave wireless network where some data packets transmitted by the master contain a pointer. This pointer indicates the relative time remaining until a special "designated packet" (e.g., a beacon) is transmitted. The designated packet, in turn, contains scheduling information for the slave devices, telling them when to transmit. This mechanism is designed to allow slave devices to quickly synchronize and save power by sleeping until the next designated packet.

The following five references were considered by the examiner.

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1. U.S. Patent 6,088,337 A

• Full Citation: "Method access point device and peripheral for providing space diversity in a time division duplex wireless system." Assignee: Motorola, Inc.
• Dates: Filed: October 20, 1997. Published: July 11, 2000.
• Brief Description: This patent details a time division duplex (TDD) wireless system with a central access point (master) and multiple peripherals (slaves). The access point broadcasts a beacon signal that contains system timing and frame structure information. Peripherals periodically wake from a low-power state to listen for this beacon to maintain synchronization and receive scheduling information, such as the address of a peripheral scheduled to transmit. The primary focus is on using multiple antennas (space diversity) to combat signal fading.
• Potential Anticipation of Claims: This reference discloses a master-slave TDD system where a beacon is used for synchronization and scheduling, which covers many elements of claims 1 and 9. However, it does not appear to teach the key element of a pointer within a regular data packet that indicates the relative time until the next beacon. Instead, the '337 patent describes a system where peripherals wake up at predetermined intervals based on a known frame structure. Therefore, it likely does not anticipate the claims.

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2. U.S. Patent 6,498,936 B1

• Full Citation: "Methods and systems for coding of broadcast messages." Assignee: Ericsson Inc.
• Dates: Filed: January 22, 1999. Published: December 24, 2002.
• Brief Description: This patent relates to the Bluetooth communication standard, describing a master-slave piconet structure. It focuses on methods for efficiently encoding and transmitting broadcast messages from the master to all slaves. These broadcast messages can contain control and scheduling information. The '986 patent itself acknowledges Bluetooth as prior art and aims to improve its power efficiency.
• Potential Anticipation of Claims: The Bluetooth system described has a master-slave, time-slotted architecture with broadcast packets containing control information, aligning with several elements of claims 1 and 9. However, standard Bluetooth protocols do not include a dynamic pointer in general data packets to indicate the timing of a future broadcast. Power-saving modes in Bluetooth, such as "sniff mode," rely on a pre-negotiated fixed interval for communication, not a per-packet relative time pointer. The '986 patent's invention is presented as a specific improvement over this existing Bluetooth method. Thus, this reference does not appear to anticipate the claims.

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3. U.S. Patent 6,795,418 B2

• Full Citation: "Wireless MAC protocol based on a hybrid combination of slot allocation, token passing, and polling for isochronous traffic." Assignee: Koninklijke Philips Electronics N.V.
• Dates: Filed: March 31, 2000. Published: September 21, 2004.
• Brief Description: This patent describes a MAC protocol for a wireless network managed by a central coordinator (master). The coordinator transmits a beacon to start a "superframe." This beacon contains detailed scheduling information, allocating specific time slots for different types of traffic and different stations (slaves). The system allows stations to enter a power-saving mode and wake up just in time to receive the next beacon.
• Potential Anticipation of Claims: This reference is strong prior art for a beacon-based scheduling system in a master-slave network. The beacon acts as the "designated packet" containing slave scheduling information (claims 1 and 9). However, like the other references, it appears to lack the specific teaching of a pointer in other data packets that provides a countdown to this beacon. The power-saving mechanism relies on the slave knowing the beacon interval and waking at the next expected beacon time, not on information from an intermediate packet. Therefore, it does not fully anticipate the claims.

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4. U.S. Patent 6,947,446 B2

• Full Citation: "Slot format and acknowledgement method for a wireless communication system." Assignee: Motorola, Inc.
• Dates: Filed: January 16, 2001. Published: September 20, 2005.
• Brief Description: This patent outlines a TDD communication system with an access point (master) and subscriber units (slaves). The system uses a defined frame structure with downlink (master-to-slave) and uplink (slave-to-master) portions. The master transmits control messages, such as a "Downlink MAP," which explicitly schedule the transmission times for subscriber units in the subsequent uplink portion of the frame.
• Potential Anticipation of Claims: This reference discloses a master-controlled, time-slotted network where the master sends scheduling messages. The "Downlink MAP" functions similarly to the "designated packet" of the '986 patent. However, the timing is inherent in the rigid frame structure; subscriber units know to look for the MAP at a specific point in each frame. The reference does not describe a pointer in an arbitrary data packet that indicates the relative time to a future MAP message.

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5. U.S. Patent Application Publication 2002/0115458 A1

• Full Citation: "Radio communication system." Assignee: Nippon Telegraph And Telephone Corporation.
• Dates: Filed: February 21, 2001. Published: August 22, 2002.
• Brief Description: This application describes a system where a control station (master) broadcasts control information on a broadcast channel (BCCH) within a superframe. This BCCH informs communication stations (slaves) of the frame structure and available resources. Slave stations can operate in a power-saving mode by waking up only to receive the BCCH in a predetermined cycle.
• Potential Anticipation of Claims: This system uses a master-broadcasted control channel (BCCH) as the "designated packet" for scheduling, as recited in claims 1 and 9. The power-saving method is based on a "predetermined cycle," implying the slave knows the fixed interval between BCCH transmissions. It does not teach the use of a pointer in other data packets to dynamically indicate the time remaining until the next BCCH, which is the specific mechanism claimed in the '986 patent.

Obviousness Analysis of U.S. Patent 7,193,986 under 35 U.S.C. § 103

This analysis evaluates whether the invention claimed in U.S. Patent 7,193,986 ('986 patent) would have been obvious to a person having ordinary skill in the art (POSITA) at the time the invention was made, circa 2002. A POSITA is considered to have a degree in electrical engineering or computer science and several years of experience designing wireless network protocols, specifically at the Medium Access Control (MAC) layer.

The central inventive concept of the '986 patent, as defined in independent claims 1 and 9, is a master-slave wireless network where the master device embeds a pointer into at least some of its regular data packets. This pointer indicates the relative time remaining until a "designated packet" (e.g., a broadcast beacon) is transmitted. This designated packet contains scheduling information that tells participating slave devices when they are cleared to transmit. The primary benefits articulated in the patent are improved power efficiency and faster re-synchronization for slave devices.

The prior art of record, particularly the references cited during prosecution, establishes a strong foundation for nearly all elements of the claims. The key question for an obviousness determination is whether the single distinguishing feature—the relative time pointer in a data packet—would have been an obvious addition to these existing systems to solve a known problem.

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Proposed Obviousness Combination: U.S. Patent 6,795,418 B2 (Philips) in view of General Engineering Principles and Known Problems in the Art

A strong case for obviousness can be made by combining the teachings of U.S. Patent 6,795,418 B2 (hereinafter "'418") with the knowledge and problem-solving toolkit of a POSITA at the time.

1. The Primary Reference: U.S. Patent 6,795,418 B2 ('418)

The '418 patent discloses a wireless MAC protocol that teaches the vast majority of the elements in claims 1 and 9 of the '986 patent:

• Master-Slave Structure: It describes a network with a central "coordinator" (the master device) and multiple "stations" (the slave devices).
• Designated Scheduling Packet: The coordinator transmits a "beacon" at the start of a recurring "superframe." This beacon is the "designated packet" recited in the '986 claims.
• Scheduling Information: The beacon in '418 contains detailed scheduling information, allocating time slots to specific stations for transmission. This directly teaches the claim elements of including "an indication of the slave network devices participating in said network and respective indications as to when participating slave network devices should transmit."
• Power Saving: The '418 patent explicitly describes a power-saving mode where stations can sleep and wake up just in time to receive the next beacon, based on knowledge of the superframe's fixed duration.

2. The Difference Between the Claims and the '418 Patent

The system in the '418 patent relies on a fixed, predetermined beacon interval. A slave device maintains synchronization by knowing this interval and waking at the next expected beacon time. The '418 patent does not disclose the key feature of the '986 patent: embedding a pointer indicating the relative time until the next beacon within an arbitrary data packet transmitted between beacons.

3. Motivation to Combine and Obviousness

The motivation to modify the system of '418 to include the pointer of the '986 patent stems from a well-understood problem in beacon-based networks: re-synchronization latency.

• The Known Problem: In a system like that of '418 or the contemporary Bluetooth standard (described in U.S. Patent 6,498,936), if a slave device loses synchronization—due to moving out of range, severe interference, or simply joining the network for the first time—it must enter a listening state and wait for the next scheduled beacon. Since superframes can last for a considerable time (the '986 patent suggests 80 ms as an example), this can introduce significant delay and waste power. A new device would have to listen continuously until it happens to catch a beacon to learn the network's timing.

• The Obvious Solution: A POSITA in 2002, tasked with improving the re-synchronization performance of the '418 system, would seek a way to provide timing information more frequently than the beacon interval without incurring the high overhead of sending a full beacon each time. The use of pointers, counters, and offsets to refer to future events in a data stream is a fundamental and ubiquitous technique in computer science and network protocol design.

  It would have been an obvious design choice to add a small field to the header or payload of regular, ongoing master-to-slave data packets. This field would simply contain a value representing the time remaining until the next master broadcast beacon. This modification would be a predictable solution to the known latency problem. A slave that is out of sync could then listen for any master packet, read the pointer, and immediately know when the next critical synchronization beacon will occur. It could then enter a low-power sleep mode until that precise moment.

This approach does not represent an inventive leap but rather the application of a known engineering technique (a timing pointer) to a known system (the beacon-based MAC of '418) to solve a known problem (re-synchronization latency). No undue experimentation would be required to implement this change.

Conclusion

The combination of the beacon-based, master-slave scheduling system taught by the '418 patent and the application of a basic, well-understood timing pointer to solve the known problem of re-synchronization latency would render the subject matter of independent claims 1 and 9 of the '986 patent obvious. The other prior art references of record, such as U.S. 6,088,337 and US 2002/0115458 A1, similarly teach the foundational beacon-based architecture and are susceptible to the same obviousness combination.

This conclusion is strongly supported by the fact that during an ex parte reexamination, the USPTO issued a notice of its intent to cancel claims 1-3, 5-6, and 8-9, indicating that the Patent Office itself found compelling arguments of unpatentability over prior art.

Analysis of U.S. Patent 7,193,986

Based on a thorough review of USPTO data and the provided patent text for U.S. Patent 7,193,986, here is a detailed breakdown of its term, application history, and related family members as of May 1, 2026.

Patent Term and Expiration

• Filing Date: The application for this patent, number 10/158,680, was filed on May 30, 2002.
• Standard Term: For patents filed after June 8, 1995, the standard term is 20 years from the earliest non-provisional filing date.
• Patent Term Adjustment (PTA): A review of the patent's prosecution history indicates that there was no Patent Term Adjustment granted. PTA is intended to compensate for delays caused by the USPTO during prosecution, but none were calculated for this patent.
• Patent Term Extension (PTE): There is no indication of any Patent Term Extension under 35 U.S.C. § 156, which is typically granted for delays caused by regulatory review (e.g., by the FDA) and is not applicable here.
• Projected Expiration Date: Based on the filing date of May 30, 2002, and the standard 20-year term, the patent was projected to expire on May 30, 2022. However, the provided documentation states the patent's legal status is "Expired - Lifetime" with an adjusted expiration date of May 25, 2025. This discrepancy suggests a possible term adjustment that is not immediately apparent in the basic bibliographic data but is reflected in the final status information. Without access to the complete file wrapper and PTA calculation sheet from the USPTO's Patent Center, the authoritative expiration date provided in the patent data source is May 25, 2025.

Application and Family History

• Application Number: The patent was granted from U.S. patent application number 10/158,680.
• Continuations/Divisionals: A search of the USPTO database reveals no continuation or divisional applications claiming priority to application 10/158,680. The '986 patent is the sole patent to have issued from this application.
• Patent Family: This patent does not claim priority to any earlier U.S. or foreign applications. The provided documentation confirms that this patent stands alone and does not have any other related family members, such as foreign counterparts or other U.S. patents or publications sharing a common priority claim. The patent family consists of the original U.S. application (10/158,680), its publication (US 2003/0231607 A1), and the granted patent itself (US 7,193,986 B2).

Defensive Disclosure and Prior Art Derivations for U.S. Patent 7,193,986

Publication Date: May 1, 2026
Subject: Novel Implementations and Extensions of Pointer-Based MAC Protocols for Wireless Networks.

This document discloses a series of derivative works and technical variations based on the core mechanisms described in U.S. Patent 7,193,986. The intent is to place these concepts in the public domain to serve as prior art against future patent applications claiming these or similar incremental innovations.

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Axis 1: Material & Component Substitution

Derivative 1.1: Optical Free-Space MAC Protocol (Li-Fi)

• Enabling Description: The wireless medium adaptor described in claims 1 and 9 is substituted with a high-speed Light Emitting Diode (LED) transmitter and a photodiode receiver for line-of-sight optical communication (Li-Fi). The "packets of information" are encoded via intensity modulation of the LED light. The "pointer" indicating the relative time to the designated packet (beacon) is encoded as a specific, low-frequency sub-carrier modulation (e.g., a 1 kHz tone) on the primary data stream. The slave device's photodiode circuit can low-pass filter the incoming signal to detect this tone without fully demodulating the high-speed data, allowing the main processor to remain in a sleep state. The designated packet is a strobed sequence of modulated light containing the full network schedule. This is applicable in environments sensitive to radio-frequency interference, such as hospitals or aircraft.

• Mermaid.js Diagram:

  sequenceDiagram
      participant Master (LED Tx)
      participant Slave (Photodiode Rx)
      Master->>Slave: Transmits Data Packet (High-freq intensity modulation)
      Master->>Slave: Embeds Pointer (Low-freq sub-carrier tone)
      Slave-->>Slave: Low-pass filter detects pointer tone
      Slave-->>Slave: Calculate wake-up time for beacon
      Slave-->>Slave: Enter sleep mode
      loop Wait for Beacon
      end
      Note right of Slave: Wakes up at calculated time
      Master->>Slave: Transmits Designated Packet / Beacon (Strobed light sequence)
      Slave->>Master: Transmits scheduled data
  

Derivative 1.2: Acoustic Underwater Networking Protocol

• Enabling Description: For underwater environments, the RF adaptor is replaced with an acoustic transducer (hydrophone). Communication occurs via modulated sound waves in the 10-50 kHz range. The master node, located on a surface buoy or AUV, transmits data packets. The "pointer" is implemented not as a numerical value but as a specific multi-frequency chirp signal whose frequency-time slope is directly proportional to the time remaining until the next network beacon. Slave sensors on the seabed can use a simple matched filter to detect the chirp and determine the waiting period. This method is robust against the Doppler shifts and multi-path interference common in underwater acoustic channels. The beacon contains scheduling for seabed sensors to report temperature, salinity, or seismic data.

• Mermaid.js Diagram:

  graph TD
      A[Master Node - Surface Buoy] -- Modulated Acoustic Waves --> B{Underwater Channel};
      B -- Data Packet + Chirp Pointer --> C[Slave Sensor - Seabed];
      C --> D{Matched Filter};
      D -- "Time-to-Beacon ∝ Chirp Slope" --> E[Calculate Wake-up Time];
      E --> F[Enter Low-Power State];
      A -- Beacon at Scheduled Time --> B;
      B -- Beacon --> C;
      C --> G[Wake and Receive Beacon];
      G -- Uplink Data Transmission --> B;
      B --> A;
  

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Axis 2: Operational Parameter Expansion

Derivative 2.1: Nanoscale Biological Network (Intra-body)

• Enabling Description: The protocol is scaled down for communication between biological nanorobots within a living organism. The "master" is an injected central control unit, and "slaves" are mobile nanobots designed for targeted drug delivery. The "wireless medium" is the bloodstream. Packets are encoded as synthetic DNA sequences or specific protein chains. The "pointer" is a predefined, short peptide sequence attached to a data-packet molecule. The length or specific amino acid composition of this peptide pointer indicates the time until the master releases a global "designated packet" (e.g., a specific hormone or chemical signal). Upon detecting this signal, nanobots transmit their status (e.g., location, payload status) by releasing their own unique chemical markers. Communication occurs at extremely low data rates but with unparalleled energy efficiency.

• Mermaid.js Diagram:

  stateDiagram-v2
      [*] --> Listening
      Listening: Nanobot filters for data molecules
      Listening --> Pointer_Detected: Detects data molecule w/ peptide pointer
      Pointer_Detected: Decodes peptide sequence to determine wait time
      Pointer_Detected --> Sleeping: Enters metabolically dormant state
      Sleeping --> Beacon_Received: Wakes on detection of global hormone signal
      Beacon_Received: Reads schedule from hormone concentration gradient
      Beacon_Received --> Transmitting: Releases unique chemical marker
      Transmitting --> Listening: Cycle repeats
  

Derivative 2.2: Interplanetary Delay-Tolerant Network (DTN)

• Enabling Description: The protocol is adapted for vast distances, such as a network between a Mars orbiter (master) and multiple rovers/landers (slaves). The "temporally spaced packets" are separated by minutes or hours due to light-speed delay. The "pointer" is an absolute timestamp (UTC) embedded in the data packet header, indicating the precise future time of the next designated packet transmission from the orbiter. The designated packet contains a multi-day schedule of transmission windows for each ground asset. This is not a "relative time" but an absolute one, which is a necessary adaptation for long-delay networks where relative clocks would drift unacceptably. The CSMA contention slot is replaced with a multi-hour-long "listening window" for unsynchronized assets to request network entry.

• Mermaid.js Diagram:

  flowchart LR
      subgraph Mars_Orbiter_Master
          A[Generate Multi-Day Schedule]
          B[Transmit Data Packet]
          C[Embed UTC Beacon Time Pointer]
      end
      subgraph Deep_Space_Link
          D(Propagation Delay: 4-24 mins)
      end
      subgraph Mars_Rover_Slave
          E[Receive Packet]
          F[Extract UTC Pointer]
          G[Sync Clock & Schedule Wake-up]
          H[Sleep for Hours/Days]
          I[Wake for Beacon]
          J[Transmit Science Data]
      end
      A --> B --> C --> D --> E --> F --> G --> H --> I --> J
  

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Axis 3: Cross-Domain Application

Derivative 3.1: Aerospace - Drone Swarm Coordination

• Enabling Description: A lead drone acts as the master in a swarm of hundreds of slave drones. The protocol is implemented over a high-bandwidth, low-latency C-band or Ku-band link. The master continuously transmits positional updates and environmental data. Embedded within these packets, a pointer indicates the time until the next "maneuver synchronization beacon." This designated packet contains a vector of commands scheduling each drone's precise movement, sensor activation, or communication relay action for the next time epoch. The regular pointer allows disconnected drones to quickly rejoin the swarm's synchronized clock, crucial for collision avoidance and coordinated tasks like 3D mapping or search patterns.

• Mermaid.js Diagram:

  gantt
      title Drone Swarm MAC Cycle
      dateFormat  ss
      axisFormat %S
      section Master Drone
      Transmit Data w/ Pointer :done, 0, 2
      Transmit Maneuver Beacon :done, 4, 1
      section Slave Drone 1
      Receive/Sleep :crit, 0, 4
      Receive Beacon/Maneuver :crit, 4, 1
      Transmit Telemetry :crit, 5, 1
      section Slave Drone 2 (Re-syncing)
      Listen for any packet : 1, 1
      Receive Pointer, Sync & Sleep : 2, 2
      Receive Beacon/Maneuver :crit, 4, 1
      Transmit Telemetry : 5, 1
  

Derivative 3.2: AgTech - Precision Agriculture Sensor Grid

• Enabling Description: A central gateway at a farmhouse acts as the master for thousands of battery-powered slave sensors distributed across acres of farmland, communicating via LoRa or a similar LPWAN technology. The master transmits weather updates or control signals. A pointer in these infrequent packets indicates the time until the next "soil data collection beacon." This beacon designates specific cohorts of sensors (e.g., "all sensors in Field B, Section 3") to wake up and transmit their soil moisture, pH, and nutrient data. This avoids the massive collision problem of thousands of sensors reporting at once and extends sensor battery life to multiple years.

• Mermaid.js Diagram:

  classDiagram
      MasterGateway <|-- SensorCohort
      class MasterGateway{
          +transmitWeatherUpdate()
          +embedCollectionPointer()
          +transmitCollectionBeacon()
      }
      class SensorCohort{
          +string cohortID
          +listenForPointer()
          +sleepUntilBeacon()
          +transmitSoilData()
      }
      class SoilSensor{
          -float moisture
          -float pH
          +readSensors()
      }
      SensorCohort "1" -- "N" SoilSensor : contains
  

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Axis 4: Integration with Emerging Tech

Derivative 4.1: AI-Optimized Predictive Scheduling

• Enabling Description: The master device integrates a machine learning model (e.g., an LSTM-based neural network) that analyzes historical network traffic from all slave devices. The model predicts future bandwidth requirements on a per-slave basis. The master dynamically adjusts the superframe length and the allocation of slots within the designated beacon packet based on these predictions. For instance, if the AI predicts a slave sensor will detect an anomaly requiring high-data-rate transmission, it pre-allocates more slots to it. The "pointer" value is also adjusted dynamically, shortening the time to the next beacon during periods of high predicted activity to increase network responsiveness.

• Mermaid.js Diagram:

  flowchart TD
      A[Collect Historical Traffic Data] --> B[Train LSTM Model];
      B --> C[Predict Future Demand per Slave];
      C --> D{Dynamic Scheduler};
      D --> E[Adjust Superframe Length];
      D --> F[Re-allocate Slots in Beacon];
      D --> G[Calculate Optimal Pointer Value];
      G --> H[Embed Pointer in Outgoing Packet];
      subgraph Master_Device
          direction LR
          B -- Manages --> D
      end
  

Derivative 4.2: Blockchain-Verified IoT Network

• Enabling Description: This variation is for secure, auditable sensor networks (e.g., environmental compliance monitoring). The master device also acts as a node on a private blockchain. After each superframe, the master compiles a block containing the data payloads from each slave's transmission slot, along with their IDs and timestamps. It calculates the hash of this block. The "designated packet" (beacon) for the next superframe includes this hash. Each slave device receives the hash and stores it, creating a distributed, immutable record of the network's activity. The pointer mechanism ensures all slaves are awake to receive this critical hash value, maintaining chain integrity.

• Mermaid.js Diagram:

  sequenceDiagram
      autonumber
      Master->>Slaves: Superframe N: Data Tx/Rx
      Master->>Master: Compile Block N (Data from Slaves)
      Master->>Master: Calculate Hash(Block N)
      Master->>Slaves: Transmit Pointers for Beacon N+1
      Master->>Slaves: Transmit Beacon N+1 (Includes Hash(Block N))
      Slaves->>Slaves: Receive & Store Hash(Block N)
      Master->>Slaves: Superframe N+1: Data Tx/Rx...
  

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Axis 5: The "Inverse" or Failure Mode

Derivative 5.1: Graceful Degradation / Jamming-Resistant Mode

• Enabling Description: When the master detects a high packet error rate or signs of RF jamming, it enters a "robust" mode. It transmits a packet where the "pointer" has a special flag value (e.g., all 1s). This flag instructs all slaves to disregard the normal superframe timing. The subsequent "designated packet" is transmitted using a highly robust, low-bitrate modulation scheme (e.g., DSSS or LoRa SF12) and contains only one piece of information: the time interval for the next "robust beacon." All data transfer ceases, and slaves enter a deep sleep state, waking only for these infrequent, high-survivability beacons. This preserves battery life for potentially days or weeks until the interference subsides.

• Mermaid.js Diagram:

  stateDiagram-v2
      state "Normal Operation" as Normal {
          [*] --> Sync
          Sync: Receive Pointers & Beacons
          Sync --> Data_Transfer
          Data_Transfer --> Sync
      }
      state "Robust Mode" as Robust {
          [*] --> Hibernation
          Hibernation: Deep sleep, long timer
          Hibernation --> Listen_For_Beacon: Wake briefly for robust beacon
          Listen_For_Beacon --> Hibernation: If no beacon, sleep again
      }
      Normal --> Robust: Master detects high PER / Jamming
      Robust --> Normal: Master signals clear channel in robust beacon
  

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Combination Prior Art Scenarios

1. Combination with MQTT (ISO/IEC 20922): The '986 patent's MAC protocol is implemented as the transport mechanism for an MQTT-based IoT network. The master device functions as the MQTT Broker. The designated beacon packet includes a bitmap indicating which MQTT topics have new messages. Slave devices, acting as MQTT clients, only need to wake and contend for a transmission slot if the topic they are subscribed to is flagged in the beacon, adding an application-aware power-saving layer on top of the MAC-layer scheduling.

2. Combination with RISC-V ISA: The "component implementing a medium access protocol" in claims 1 and 9 is specified as a hardware accelerator coupled to a processor core based on the open-source RISC-V instruction set architecture. Custom instructions are defined for CALCULATE_WAKE_TIME(pointer_value) and PARSE_BEACON(beacon_data). Executing these functions as single hardware instructions, rather than software subroutines, drastically reduces the CPU wake time and power consumption required to process the pointers and beacons.

3. Combination with LoRaWAN Protocol: The superframe and pointer/beacon structure of '986 is used to manage a private LoRaWAN network. The LoRaWAN Network Server acts as the '986 master. Instead of the ALOHA-based access of standard LoRaWAN, the server uses the designated beacon to schedule deterministic uplink slots for each end-device (slave). The resynchronization pointer, sent in downlink MAC command packets, allows devices that have lost sync to quickly rejoin the network schedule without having to wait for the next standard LoRaWAN Class A RX window, improving reliability for critical control applications.