US 11700084

Here is a concise summary of US patent 11700084:

US Patent 11700084 Summary

• Title: Wireless communication method and wireless communication terminal for coexistence with legacy wireless communication terminal
• Assignee: Wilus Institute of Standards and Technology Inc.
• Inventors: Geonjung KO, Jinsam Kwak, Juhyung Son
• Filing Date: 2021-08-20
• Issue Date: 2023-07-11
• Abstract: The patent describes a wireless communication terminal equipped with a transceiver and a processor. This processor is configured to receive a non-legacy physical layer frame and extract a legacy signaling field (L-SIG) from it, which contains information that legacy wireless communication terminals can decode. From this L-SIG, the processor obtains length information indicating the duration of the non-legacy physical layer frame. It further extracts other information by analyzing a remaining value derived from dividing the length information by the data size transmittable per symbol of a legacy physical layer frame (e.g., 3 octets when the legacy data rate is 6 Mbps). Finally, the processor determines the number of data symbols within the non-legacy physical layer frame using a specific mathematical equation: Num_HE_Data_SYM = ⌊ (L_LENGTH-3)×8/L_DATARATE ⌋ − ⌈ T_HE_PREAMBLE/T_SYM ⌉ − PE_Disambiguity, where L_LENGTH is the length information, PE_Disambiguity is a specific field value, T_HE_PREAMBLE is the duration of the non-legacy preamble, and T_SYM is the duration of a data symbol in the non-legacy frame.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes a wireless communication device (terminal) that can communicate wirelessly. The terminal includes a transceiver for sending and receiving signals and a processor to manage communication. The processor is designed to:

  1. Receive a wireless signal called a "non-legacy physical layer frame." This frame contains a specific part, a "legacy signaling field" (L-SIG), which is structured so that older (legacy) wireless devices can understand it.
  2. Extract length information from this L-SIG, which indicates how long the non-legacy physical layer frame will last after the L-SIG.
  3. Extract additional information by calculating a remainder when the previously obtained length information is divided by a standard amount of data a legacy device can transmit in one symbol (for example, 3 bytes if the legacy data rate is 6 Mbps).
  4. Calculate the exact number of data symbols within the non-legacy physical layer frame using a specified formula. This formula uses the extracted length, a "PE Disambiguity" value, and the durations of the non-legacy preamble and data symbols. This mechanism helps the new terminal to correctly interpret the frame length while allowing older devices to coexist without interference.

• Independent Claim 8: This claim outlines a method (a series of steps) for a wireless communication terminal to perform its operations. The method involves:

  1. Receiving a non-legacy physical layer frame that contains a legacy signaling field (L-SIG), which is understandable by legacy wireless terminals.
  2. Obtaining length information from the L-SIG, which specifies the duration of the non-legacy physical layer frame starting from after the L-SIG.
  3. Obtaining further information by calculating a remaining value from dividing the length information by the data size that a legacy physical layer frame symbol can transmit (e.g., 3 octets for a 6 Mbps data rate).
  4. Determining the number of data symbols in the non-legacy physical layer frame using the same specific equation as detailed in Claim 1. This method enables the terminal to efficiently operate with non-legacy frames while ensuring compatibility and preventing collisions with legacy terminals.

Litigation Information:
The Google Patents page for US11700084B2 indicates that the patent family is involved in litigation. However, specific details regarding its involvement in CAFC 2026 dockets were not retrieved in this analysis.

Darts-ip, a patent case law database, indicates that the patent family of US11700084 has been involved in litigation. However, the specific details regarding the plaintiff(s), defendant(s), jurisdiction, case number, filing date, and outcome or current status are not publicly available in the search results and require a subscription to the Darts-ip service for full access to the case history and documents.

Proceedings overview

There are no AIA trial proceedings on file for US patent 11700084 in the USPTO Open Data Portal as of the most recent ingest. Web searches also did not identify any Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) proceedings for this patent. This indicates that the patent has not yet faced any challenges before the Patent Trial and Appeal Board (PTAB).

Strategic summary

As of the current date, US patent 11700084 has no claims that have been canceled or sustained through AIA trial proceedings. All claims remain untested by the PTAB. This means that a defendant currently facing assertion of this patent would have the full range of prior-art grounds available for a potential IPR, PGR, or CBM petition, without any estoppel limitations under 35 U.S.C. § 315(e)(2). There is no pattern of PTAB challenges for this patent, nor is there any indication of involvement by defensive aggregators like Unified Patents.

Recommended next steps

Since no PTAB activity exists for US11700084, a defendant facing assertion of this patent should be aware that the claims have not been subjected to PTAB scrutiny. The absence of PTAB activity can be a signal that the patent may not have been widely asserted or considered highly vulnerable to prior art challenges by previous defendants.

For a defendant considering an invalidity challenge, initiating an IPR (or PGR, if applicable) could be a viable strategy to test the patentability of the claims based on prior art. This would involve:

• Conducting thorough prior art searches to identify strong references for §§ 102 and 103 challenges.
• Preparing and filing a petition with the PTAB, which would then be subject to an institution decision. If instituted, the trial typically concludes within one year.

The Patent Trial and Appeal Case Tracking System (P-TACTS) is the official system for tracking AIA trial proceedings, and users can search for cases by patent number.

Inventors

• Geonjung KO (SK Telecom Co Ltd)
• Jinsam Kwak (SK Telecom Co Ltd)
• Juhyung Son (SK Telecom Co Ltd)

Original assignee

SK Telecom Co Ltd is a South Korean wireless telecom operator, with a primary line of business in mobile telephone, wireless data, information, and communication services. The company has also expanded into AI infrastructure and investment activities. SK Telecom has commercialized 5G technology in Korea. They are currently an operating company.

Assignment timeline

• 2021-12-18 (executed) / recorded 2022-12-18 — Reel 062152/0001
  • Conveyance: License
  • Assignor: SK TELECOM CO., LTD.
  • Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: BAE, KIM & LEE IP LAW GROUP, 1004, 521, Teheran-ro, Gangnam-gu, Seoul, 06185, Republic of Korea.
  • Context: exclusive license for the patent.
• 2023-05-10 (executed) / recorded 2023-05-10 — Reel 063641/0458
  • Conveyance: Assignment
  • Assignor: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Assignee: SK TELECOM CO., LTD., WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: BAE, KIM & LEE IP LAW GROUP, 1004, 521, Teheran-ro, Gangnam-gu, Seoul, 06185, Republic of Korea. (This correspondent recurs in this chain.)
  • Context: reassignment of assignor's interest.
• 2023-05-10 (executed) / recorded 2023-05-10 — Reel 063641/0458
  • Conveyance: Assignment
  • Assignor: KO, GEONJUNG; KWAK, JINSAM; SON, JUHYUNG
  • Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: BAE, KIM & LEE IP LAW GROUP, 1004, 521, Teheran-ro, Gangnam-gu, Seoul, 06185, Republic of Korea. (This correspondent recurs in this chain.)
  • Context: assignment of inventors' interest.
• 2024-06-20 (executed) / recorded 2024-06-20 — Reel 065330/0394
  • Conveyance: Assignment
  • Assignor: SK TELECOM CO., LTD.
  • Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: BAE, KIM & LEE IP LAW GROUP, 1004, 521, Teheran-ro, Gangnam-gu, Seoul, 06185, Republic of Korea. (This correspondent recurs in this chain.)
  • Context: reassignment of assignor's interest.
• 2020-08-31 (executed) / recorded 2025-02-26 — Reel 066060/0695
  • Conveyance: Corrective Assignment
  • Assignor: SK TELECOM CO., LTD.
  • Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: BAE, KIM & LEE IP LAW GROUP, 1004, 521, Teheran-ro, Gangnam-gu, Seoul, 06185, Republic of Korea. (This correspondent recurs in this chain.)
  • Context: corrective assignment to clarify exclusive license agreement date.

Timeline diagram

timeline
    title Ownership of US 11700084
    2015 : Prior art date
    2021 : Application filed
         : License to Wilus Institute
    2023 : Issued
         : Assigned from Wilus to SK/Wilus
         : Inventors assigned to Wilus
    2024 : Assigned from SK to Wilus
    2025 : Corrective Assignment

NPE / troll-pattern signals

1. Shell-entity transfer — unclear. While Wilus Institute of Standards and Technology Inc. has received multiple assignments and licenses, there isn't enough public information to definitively characterize it as a shell entity. Their name suggests a research or standards-focused organization, but without details on products or specific business operations beyond patent holding, it's hard to make a definitive call.
2. Known asserter in the chain — not present. None of the assignees (SK Telecom Co Ltd or Wilus Institute of Standards and Technology Inc.) are listed among the common NPEs or patent trolls such as Acacia Research, Marathon Patent Group, Intellectual Ventures, IPNav, Wi-LAN, Mosaid / Conversant, Vringo, Pendrell, Innovatio IP Ventures, MPHJ Technology, Lumen View Technology, Round Rock Research, or Erich Spangenberg entities.
3. Repeat correspondent across the chain — present. BAE, KIM & LEE IP LAW GROUP of Seoul, Republic of Korea, is listed as the correspondent for all recorded assignments: 2022-12-18 (Reel 062152/0001), 2023-05-10 (Reel 063641/0458 - twice), 2024-06-20 (Reel 065330/0394), and 2025-02-26 (Reel 066060/0695). This firm handled all transfers involving SK Telecom and Wilus Institute.
4. Cascading transfers — not present. While there are multiple assignments, they primarily involve transfers between SK Telecom and Wilus Institute, often re-establishing or clarifying ownership/licensing. These do not appear to be consecutive transfers through chained, anonymous LLCs.
5. Pre-litigation transfer — unclear. There is no litigation information provided in the patent text or search results to make this determination.
6. Bankruptcy fire-sale — not present. There is no indication of SK Telecom Co Ltd or Wilus Institute of Standards and Technology Inc. having filed for bankruptcy.
7. Privateering — unclear. There is no information to suggest that SK Telecom Co Ltd transferred the patent to Wilus Institute for assertion on its behalf against competitors.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at a known defensive aggregator like RPX, Allied Security Trust (AST), LOT Network, Unified Patents, or Open Invention Network.

Verdict

Insufficient data. While the repeated correspondent, BAE, KIM & LEE IP LAW GROUP, is a signal that often accompanies NPE activity, the primary assignee (SK Telecom) is a large operating company. Without more information on Wilus Institute of Standards and Technology Inc.'s operations, and without any documented litigation, it's not possible to definitively classify this as an NPE assertion.

USPTO Assignment Center search page: https://assignment.uspto.gov/patent/index.html

To identify the most relevant prior art for US patent 11700084, I will perform a comprehensive review of the patent document itself, focusing on the "References Cited" section. The USPTO's Patent Public Search tool is the authoritative source for this information.

Once I have the list of cited prior art, I will gather the requested details for each: full citation, publication/filing date, a brief description (based on their relevance to US11700084), and which claim(s) of US11700084 they potentially anticipate under 35 U.S.C. § 102.

Since I don't have direct access to the full USPTO database, I will rely on the provided patent text for the references cited and then explain how to analyze them for anticipation.

Here's a breakdown of the process I will follow to fulfill your request once I have the list of references:

For each cited reference:

1. Full Citation: Extract the complete patent or publication number, inventor(s), and publication date.
2. Publication/Filing Date: Note the relevant date(s). For a patent, this would typically be the publication date.
3. Brief Description: Based on the abstract, claims, and figures of the cited prior art, I will summarize its core inventive concept. I will relate this description back to the problems and solutions addressed by US11700084, if explicitly stated.
4. Potential Anticipation (35 U.S.C. § 102):
   • Understanding Anticipation: Under 35 U.S.C. § 102, a claim is anticipated if every element of the claimed invention is disclosed, either explicitly or inherently, in a single prior art reference. The prior art must be "enabled," meaning it provides a description that allows a person of ordinary skill in the art to make and use the disclosure.
   • Analysis for US11700084: I will compare the elements of the independent claims of US11700084 against the disclosure of each prior art reference.
     • Identify Key Elements of US11700084's Independent Claims: I will focus on the unique aspects of US11700084, such as methods for coexisting with legacy wireless communication terminals, specific physical layer frame structures (e.g., non-legacy physical layer frames, L-SIG, HE-SIG), and the logic for determining frame durations, packet extensions, and signaling information.
     • Compare Elements to Prior Art: For each prior art reference, I will assess if it discloses every single element of an independent claim of US11700084.
     • State Potential Anticipation: If a prior art reference appears to disclose all elements of a specific claim, I will identify that claim as potentially anticipated. If only some elements are disclosed, I will note that, but it would not be a case of anticipation under § 102, but rather obviousness under § 103 (which is not requested).

Please provide the list of prior art citations from US11700084, and I will proceed with the detailed analysis.

Under 35 U.S.C. § 103, an invention is considered obvious 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 (PHOSITA). The patent text for US11700084 itself provides ample prior art and motivations for combining elements.

Identified Prior Art References

The patent text extensively describes various IEEE 802.11 wireless communication standards as existing technologies, serving as prior art:

1. IEEE 802.11a: This standard uses Orthogonal Frequency Division Multiplexing (OFDM) and operates in the 5 GHz band. Its physical layer frames include a Legacy Short Training Field (L-STF), a Legacy Long Training Field (L-LTF), and a Legacy Signal Field (L-SIG). The L-SIG is modulated using Binary Phase Shift Keying (BPSK) and contains rate and length information (L_LENGTH) that 802.11a terminals use to determine the frame's duration and defer channel access.
2. IEEE 802.11n: This standard supports higher throughput (HT) and uses Multiple Input, Multiple Output (MIMO) technology. Its physical layer frames incorporate a legacy preamble (for 802.11a compatibility) followed by an HT preamble. The HT preamble's initial symbols (HT-SIG1 and HT-SIG2) are modulated with Quadrature Binary Phase Shift Keying (QBPSK), which 802.11n terminals use for auto-detection to distinguish 802.11n frames from 802.11a frames.
3. IEEE 802.11ac: This standard offers wider bandwidth, more MIMO spatial streams, multi-user MIMO, and higher-density modulation (256 QAM). Its physical layer frames also include a legacy preamble (for 802.11a compatibility) followed by a Very High Throughput (VHT) preamble. To avoid conflicting with 802.11n auto-detection, the first symbol of the VHT-SIG-A (VHT-SIG-A1) is modulated with BPSK, and the second symbol (VHT-SIG-A2) is modulated with QBPSK, allowing 802.11ac terminals to distinguish their frames from 802.11a and 802.11n frames.

Problem Addressed by US11700084

The patent explicitly states its objective is to provide an "efficient wireless communication method in a wireless communication environment in which a legacy wireless communication terminal and a non-legacy wireless communication terminal coexist." It highlights a key problem: "a legacy wireless communication terminal that does not support non-legacy physical layer frames may not decode information on non-legacy physical layer frames," leading to issues like indefinite channel sensing and transmission collisions.

Obviousness Analysis of US11700084

The core claimed invention of US11700084 pertains to a non-legacy wireless communication terminal and method where a non-legacy physical layer frame includes a legacy signaling field (L-SIG) containing length information (L_LENGTH) for coexistence with legacy terminals. A novel aspect claims to obtain "information other than information on the duration of the non-legacy physical layer frame through a remaining value obtained by dividing the length information by a data size transmittable by a symbol of a legacy physical layer frame." This additional information is then used, along with L_LENGTH, to determine the number of symbols of data in the non-legacy frame and other parameters like packet extension duration.

Combination of Prior Art References

The combination of IEEE 802.11ac (or 802.11n) with IEEE 802.11a and general knowledge of wireless communication design would render the claims of US11700084 obvious to a PHOSITA.

Motivation for Combination:

A PHOSITA in the field of wireless communications, tasked with designing a new, high-efficiency wireless standard (e.g., 802.11ax, as discussed in the patent) that must coexist with existing legacy standards (like 802.11a/n/ac), would be strongly motivated by the following:

1. Ensuring Backward Compatibility and Channel Protection: It is a well-established practice in wireless standards to ensure that newer technologies do not disrupt older ones. The IEEE 802.11n and 802.11ac standards already demonstrate this by including an 802.11a-compatible L-SIG in their frames. This L-SIG, containing L_LENGTH, allows older 802.11a terminals to correctly interpret the frame duration and defer their own transmissions, thereby preventing collisions. The patent explicitly acknowledges this: "The 11ac physical layer frame includes a legacy preamble... and the 11a wireless communication terminal protects the 11ac physical layer frame based on information extracted from the legacy preamble."
2. Efficiently Conveying New System Information: Beyond basic coexistence, newer standards need to convey specific information for their advanced features (e.g., MIMO configurations, bandwidth, modulation schemes). 802.11n achieved this by using specific QBPSK modulation for its HT-SIG immediately after the L-SIG, and 802.11ac used a BPSK/QBPSK sequence for its VHT-SIG-A. This demonstrates a clear architectural pattern in the prior art: use the L-SIG for legacy protection, then use subsequent fields or aspects for non-legacy signaling.
3. Optimizing Limited Signaling Resources: The patent itself points out a challenge: "the duration of a symbol of a non-legacy physical layer frame is different from the duration of a symbol of a legacy physical layer frame." When a non-legacy terminal calculates the L_LENGTH (which is based on legacy symbol durations) to represent the non-legacy frame's overall duration, there can be a discrepancy. The patent illustrates this with a ceiling operation (e.g., FIG. 24, reference numeral 2401), which inherently creates an "increment of duration" or a "remaining value" when the actual non-legacy frame duration doesn't perfectly align with an integer number of legacy symbols.

Rationale for Obviousness:

A PHOSITA, observing the existing practices in 802.11n and 802.11ac (where L-SIG is used for coexistence and subsequent fields carry non-legacy information), and also recognizing the mathematical consequence of calculating L_LENGTH from non-legacy frame parameters (i.e., the "remaining value" or "increment" due to differing numerologies and the use of ceiling functions as depicted in FIG. 24 and described in its text), would find it an obvious design choice to exploit this "remaining value."

The motivation would be to "hide" or embed additional, low-bitrate signaling information for the non-legacy terminal within this naturally occurring "remainder" or "increment" from the L_LENGTH calculation. This allows the non-legacy terminal to convey extra data without altering how legacy terminals interpret the crucial L_LENGTH field for overall frame duration. The patent itself suggests this use, stating that a "PE-Disambiguity field may be set based on... an increment of duration to set a value of the length information based on a duration of a symbol of legacy physical layer frame." This directly teaches using this increment for additional signaling.

Once this concept of embedding additional information via the "remaining value" is established, the subsequent steps of the non-legacy terminal (such as determining the number of data symbols or packet extension duration using this embedded information along with the L_LENGTH) would be a matter of routine engineering. The equations provided in the claims merely represent the mathematical implementation of retrieving and utilizing these values.

Therefore, the combination of the known L-SIG structure and its role in backward compatibility (from 802.11a, 802.11n, and 802.11ac), coupled with the recognized need for additional signaling in new standards (from 802.11n's HT-SIG and 802.11ac's VHT-SIG), and the understanding of how L_LENGTH calculations can generate a "remaining value" (as explained in the patent's background and problem description), would lead a PHOSITA to combine these elements to arrive at the claimed invention. The PHOSITA would be motivated to efficiently convey non-legacy information without disturbing legacy operations, and exploiting inherent mathematical artifacts in compatibility calculations is a logical engineering approach.