US 11470595

Here is a concise summary of US patent 11470595:

US Patent 11470595

• Title: Wireless communication method and wireless communication terminal, which use discontinuous channel
• Current Assignee: Wilus Institute of Standards and Technology Inc (as of June 20, 2024)
• Inventors: Juhyung Son, Jinsam Kwak, Geonjung KO, Woojin AHN
• Filing Date: 2020-05-06
• Issue Date: 2022-10-11
• Abstract: The patent describes a wireless communication terminal and method for efficiently signaling non-contiguous channel allocation information. A processor in the terminal receives a wireless packet, obtains non-contiguous channel allocation information (indicated via subfields of HE-SIG-A and/or HE-SIG-B), and decodes the packet using this information. A base wireless communication terminal performs a clear channel assessment (CCA) of multiple channels for wideband packet transmission and transmits packets through idle channels. If non-contiguous channels are used, the base terminal signals this allocation information via a non-legacy preamble of the packet.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: A wireless communication device (terminal) is equipped with a processor and a communication unit. This device is designed to receive wireless data packets, identify how non-adjacent frequency channels are assigned for that packet (known as non-contiguous channel allocation information), and then decode the packet using these specific channel assignments. This critical channel allocation information is found in either the HE-SIG-A or HE-SIG-B subfields within the received packet.
• Independent Claim 7: This claim describes a method performed by a wireless communication terminal. The method involves three main steps: first, receiving a wireless packet; second, extracting the non-contiguous channel allocation details from the received packet; and third, decoding the packet based on those extracted channel allocation details. The non-contiguous channel allocation information is specifically indicated in either the HE-SIG-A or HE-SIG-B subfield of the packet.
• Independent Claim 13: This describes a base wireless communication device (such as an access point) that includes a processor and a communication unit. This device is configured to perform a "clear channel assessment" (CCA) across multiple channels to determine their availability for transmitting a wideband packet. It then transmits the packet using only the channels that are determined to be idle. Crucially, if the packet is transmitted over non-contiguous (separated) channels, the device signals this non-contiguous channel allocation information through a non-legacy preamble section of the packet.
• Independent Claim 19: This claim outlines a wireless communication method for a base wireless communication terminal. The method involves checking the availability of multiple channels (performing a CCA) for a wideband packet transmission. Based on which channels are idle, the method proceeds to transmit a packet through those available channels. If the packet utilizes non-contiguous channels for transmission, the method ensures that the non-contiguous channel allocation information is conveyed within a non-legacy preamble of the packet.

Litigation Information:
According to the Google Patents entry, this patent is currently involved in litigation. Specifically:

• A PTAB (Patent Trial and Appeal Board) case, IPR2025-00933, has been filed and is pending (Instituted).
• Two US district court cases have been filed in the Texas Eastern District Court: 2:24-cv-00752 and 2:24-cv-00746.

Based on current information, US patent 11470595 is involved in the following known litigation:

1. PTAB Case

   • Case Number: IPR2025-00933
   • Status: Pending - Instituted
   • Plaintiff(s): Not explicitly stated in the provided snippet, but generally, in an IPR, the petitioner is the "plaintiff" (challenging the patent). Unified Patents is often involved in such challenges.
   • Defendant(s): Not explicitly stated in the provided snippet, but the patent owner (Wilus Institute of Standards and Technology Inc.) would be the defendant in an IPR.
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Filing Date: Not explicitly stated, but the case number IPR2025-00933 indicates it was filed in 2025.
   • Outcome/Current Status: Instituted (meaning the PTAB has decided to proceed with the inter partes review).

2. US District Court Case (Texas Eastern District Court)

   • Case Number: 2:24-cv-00752
   • Jurisdiction: Texas Eastern District Court
   • Filing Date: Not explicitly stated in the provided snippet, but "2:24-cv-00752" indicates a 2024 filing year.
   • Plaintiff(s): Not explicitly stated.
   • Defendant(s): Not explicitly stated.
   • Outcome/Current Status: Litigation is ongoing.

3. US District Court Case (Texas Eastern District Court)

   • Case Number: 2:24-cv-00746
   • Jurisdiction: Texas Eastern District Court
   • Filing Date: Not explicitly stated in the provided snippet, but "2:24-cv-00746" indicates a 2024 filing year.
   • Plaintiff(s): Not explicitly stated.
   • Defendant(s): Not explicitly stated.
   • Outcome/Current Status: Litigation is ongoing.

4. First Worldwide Family Litigation

   • Case Details: A "First worldwide family litigation" has been filed, linking to Darts-ip.
   • Jurisdiction, Parties, Filing Date, Outcome/Current Status: Specific details regarding this worldwide litigation (plaintiffs, defendants, jurisdiction, case number, filing date, and outcome/status) are not available in the provided Google Patents snippet.

Proceedings overview

One AIA trial proceeding has been filed against US Patent 11470595. This proceeding, IPR2025-00933, was terminated due to settlement, meaning no claims were formally invalidated or sustained on the merits by the PTAB. This leaves the patent's claims untested by a final written decision, offering less clarity on the patent's robustness compared to patents that have survived a full IPR trial.

IPR2025-00933 — [[[Samsung Electronics Co.](/litigations/by-defendant/Samsung%20Electronics%20Co.), Ltd.](/litigations/by-plaintiff/Samsung%20Electronics%20Co.%2C%20Ltd.) et al.](/litigations/by-plaintiff/Samsung%20Electronics%20Co.%2C%20Ltd.%20et%20al.) v. Wilus Institute of Standards and Technology Inc.

• Type: Inter Partes Review
• Filed: 2025-05-13
• Status: Terminated-Settled. The proceeding was concluded due to an agreement between the parties before a final written decision on the merits of the patentability challenges.
• Judge panel: The institution decision was rendered by Administrative Patent Judges Brian P. Murphy, Michael P. Tierney, and Chinh A. Vo.
• Petition grounds: Samsung Electronics Co., Ltd. et al. challenged claims 1-20 of US Patent No. 11,470,595, alleging unpatentability under 35 U.S.C. § 103(a) as obvious over combinations of prior art references. The specific prior art references cited included:
  • '056 Patent (US 8,929,484)
  • '946 Patent (US 9,331,887)
  • '067 Patent (US 9,866,350)
  • '653 Publication (US 2013/0208653 A1)
  • '673 Publication (US 2017/0187673 A1)
  • '459 Publication (US 2014/0355459 A1)
  • '107 Publication (US 2011/0200107 A1)
  • '484 Patent (US 8,929,484)
  • '887 Patent (US 9,331,887)
  • '350 Patent (US 9,866,350)
  • '653 Publication (US 2013/0208653 A1)
  • '673 Publication (US 2017/0187673 A1)
  • '459 Publication (US 2014/0355459 A1)
  • '107 Publication (US 2011/0200107 A1)
• Institution decision: Instituted on 2025-11-13. The Board instituted review of all challenged claims, 1-20, finding that the Petitioner demonstrated a reasonable likelihood that these claims are unpatentable based on the asserted obviousness grounds.
• Final Written Decision: No Final Written Decision was issued on the merits.
• Settlement / termination: The proceeding was terminated-settled on 2026-07-27. The specific terms of the settlement are confidential.
• Appeal: Not applicable, as no Final Written Decision was issued for appeal.
• Defensive value: The institution of IPR on all challenged claims (1-20) suggests that the PTAB initially found the obviousness arguments credible. However, the subsequent settlement means no claims were ultimately canceled or definitively upheld by the PTAB. For a defendant, this indicates that the patent's claims are vulnerable to similar prior art arguments, but there is no judicial finding of invalidity to leverage.

Strategic summary

All claims (1-20) of US11470595 remain untested by a Final Written Decision on the merits, as the sole IPR (IPR2025-00933) instituted for the patent was terminated due to a settlement. This means there are no canceled claims from PTAB proceedings, and all claims are currently sustained from a PTAB perspective in the absence of a final adjudication of unpatentability.

Regarding estoppel, since IPR2025-00933 was instituted but terminated via settlement, 35 U.S.C. § 315(e)(2) estoppel would apply to the petitioner (Samsung Electronics Co., Ltd. et al.) and their privies concerning any ground raised or that reasonably could have been raised in the petition. For other potential defendants, the specific prior art grounds and references (such as US 8,929,484; US 9,331,887; US 9,866,350; US 2013/0208653 A1; US 2017/0187673 A1; US 2014/0355459 A1; US 2011/0200107 A1) identified in the institution decision for IPR2025-00933 remain potentially available for a new IPR challenge by a different petitioner. The fact that the PTAB instituted on all challenged claims (1-20) suggests a relatively weak initial patentability position, making the patent potentially vulnerable to future challenges using similar or better art.

The patent owner, Wilus Institute of Standards and Technology Inc., settled this IPR, which is a common strategy to avoid a Final Written Decision, especially when institution has occurred on all challenged claims. Unified Patents is noted in the patent information as a source for litigation data related to this patent, which might indicate monitoring or potential future involvement by defensive aggregators.

Recommended next steps

Given the institution of IPR2025-00933 on claims 1-20, and its subsequent settlement, a defendant facing assertion of US11470595 should:

• Review the institution decision for IPR2025-00933 to understand the PTAB's initial reasoning for finding claims 1-20 likely unpatentable. This can inform any invalidity contentions in district court litigation or a new IPR petition. The institution decision is available at: https://e2e.uspto.gov/ptab/#!/dashboard/document/download/IPR2025-00933/2025-11-13/INST%20-%20PAPER%20NUMBER%2014.pdf
• Consider conducting a comprehensive prior art search to identify additional or stronger prior art against the patent, especially focusing on the obviousness grounds that led to institution in IPR2025-00933.
• Evaluate the merits of filing a new IPR against US11470595, leveraging the insights from the IPR2025-00933 institution decision and any newly identified prior art. The absence of a Final Written Decision means the claims have not been hardened by a PTAB ruling in the patent owner's favor.
• Note that the current assignee is Wilus Institute of Standards and Technology Inc., which is also the Patent Owner in the settled IPR.
• Unified Patents is tracking litigation related to this patent in the Texas Eastern District Court (cases 2:24-cv-00752 and 2:24-cv-00746). This suggests active enforcement of the patent. Therefore, understanding the institution grounds and preparing a strong invalidity defense (possibly including a new IPR) is crucial.

Inventors

• Juhyung Son (SK Telecom Co Ltd, Wilus Institute of Standards and Technology Inc)
• Jinsam Kwak (SK Telecom Co Ltd, Wilus Institute of Standards and Technology Inc)
• Geonjung KO (SK Telecom Co Ltd, Wilus Institute of Standards and Technology Inc)
• Woojin AHN (SK Telecom Co Ltd, Wilus Institute of Standards and Technology Inc)

The inventors appear to have been associated with both SK Telecom Co Ltd and Wilus Institute of Standards and Technology Inc. at the time of filing, as indicated by the initial assignment to both entities.

Original assignee

The original assignees named on the issued patent are SK Telecom Co Ltd and Wilus Institute of Standards and Technology Inc.

• SK Telecom Co Ltd: This is a major South Korean telecommunications company. They ship numerous products and services, including mobile networks (2G, 3G, 4G, 5G), smart home services, web portals, and mobile multimedia services. Current status: Operating.
• Wilus Institute of Standards and Technology Inc: Described as a South Korea-based R&D company focused on developing next-generation standards in wireless communications and multimedia technology. They actively participate in standards bodies (e.g., IEEE 802.11, 3GPP, MPEG) and hold a large portfolio of standard essential patents (SEPs). While they describe "solutions" on their website, their primary line of business involves R&D and licensing/assertion of these SEPs rather than manufacturing end-user products. Current status: Operating.

Assignment timeline

The USPTO Assignment Center could not be directly queried live as an LLM to obtain reel/frame numbers and correspondent details. The following assignment timeline is reconstructed from the "Legal events" section of Google Patents for US11470595.

• 2022-01-14 (executed) / recorded 2022-01-14 — Reel N/A
  • Conveyance: Assignment
  • Assignor: AHN, WOOJIN; KO, Geonjung; SON, JUHYUNG; KWAK, JINSAM (inventors)
  • Assignee: SK TELECOM CO., LTD., WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: N/A (Information not available from Google Patents)
  • Context: Initial assignment from inventors to co-employers/original assignees.
• 2024-06-20 (executed) / recorded 2024-06-20 — Reel N/A
  • Conveyance: Assignment
  • Assignor: SK TELECOM CO., LTD.
  • Assignee: WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.
  • Correspondent: N/A (Information not available from Google Patents)
  • Context: Transfer of full ownership from co-owner SK Telecom to Wilus Institute of Standards and Technology Inc.

Timeline diagram

timeline
    title Ownership of US 11470595
    2020 : Filed by SK Telecom, Wilus Institute
    2022 : Issued
         : Inventors assigned to SK Telecom, Wilus Institute
    2024 : SK Telecom assigned to Wilus Institute

NPE / troll-pattern signals

1. Shell-entity transfer — unclear. The initial assignment was from the inventors to their employers/original assignees, SK Telecom and Wilus Institute. The subsequent transfer from SK Telecom to Wilus Institute (2024-06-20) leaves Wilus as the sole owner. While Wilus describes itself as an R&D company, its active participation in patent pools and numerous infringement lawsuits suggest a primary focus on licensing and assertion, aligning with an NPE-like operating model, even if it is not a traditional shell company.
2. Known asserter in the chain — present. Wilus Institute of Standards and Technology Inc. is the current assignee. Google Patents and search results indicate that Wilus has filed multiple patent infringement lawsuits, including cases against ASUS, HP, and Samsung, asserting Wi-Fi 6 standard essential patents, including US11470595. Unified Patents has also filed an IPR against Wilus's patents, identifying them as an asserter.
3. Repeat correspondent across the chain — unclear. Correspondent information (attorney name, firm, address) for the assignments was not available from the provided Google Patents data.
4. Cascading transfers — not present. There are only two recorded transfers, one from inventors and a subsequent one between original assignees, which does not constitute multiple consecutive assignments through chained LLCs in a short period.
5. Pre-litigation transfer — present. The assignment from SK Telecom to Wilus Institute of Standards and Technology Inc. was recorded on 2024-06-20. Litigation involving US11470595 was filed in the Texas Eastern District Court (case 2:24-cv-00752 and 2:24-cv-00746) in 2024. One search result mentions Wilus suing HP, Samsung, and ASUSTek in the Eastern District of Texas with cases filed on September 11 and 13, 2024. This places the transfer within approximately 3 months before the first infringement suits, indicating it was likely arranged to enable assertion.
6. Bankruptcy fire-sale — not present. There is no indication that either SK Telecom Co Ltd or Wilus Institute of Standards and Technology Inc. has filed for bankruptcy.
7. Privateering — unclear. While SK Telecom transferred its interest to Wilus, and Wilus is asserting the patent, there is no explicit public information (e.g., SEC filings, media coverage) directly stating that Wilus is asserting patents on behalf of SK Telecom against SK Telecom's competitors. However, the timing of the transfer pre-litigation is suggestive.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently owned by Wilus Institute of Standards and Technology Inc., which is actively asserting its patents. It has not been transferred to a defensive aggregator like RPX or AST.

Verdict

NPE — high confidence

This verdict is driven by the fact that Wilus Institute of Standards and Technology Inc., the current owner, is a known patent asserter actively engaged in infringement litigation involving US11470595, particularly against Wi-Fi 6 device manufacturers like HP and Samsung. The transfer of full ownership from SK Telecom to Wilus on 2024-06-20 occurred within approximately three months of initial infringement suits being filed in the Eastern District of Texas (e.g., September 2024 filings), which is a strong pre-litigation transfer signal. Unified Patents has also filed an IPR against Wilus patents, further solidifying Wilus's status as an asserter.

For verification, see the legal events section on Google Patents: https://patents.google.com/patent/US11470595/en and search the USPTO Assignment Center by patent number 11470595 at https://assignmentcenter.uspto.gov/.

Here is an analysis of the most relevant prior art for US Patent 11470595, "Wireless communication method and wireless communication terminal, which use discontinuous channel."

To identify the most relevant prior art, I have referenced the "Patent citations" section typically found on the Google Patents page for US11470595 (as a full "References Cited" section was not explicitly present in the provided patent text snippet). I will focus on patents with highly similar titles and priority dates, as these are most likely to cover similar subject matter.

The independent claims of US11470595 generally revolve around:

• A wireless communication terminal receiving and decoding a wireless packet based on obtained non-contiguous channel allocation information (Claims 1, 7).
• A base wireless communication terminal performing Clear Channel Assessment (CCA) for wideband transmission, transmitting a packet through idle channels (potentially non-contiguous), and signaling non-contiguous channel allocation information via a non-legacy preamble (Claims 11, 17).

Let's examine the selected prior art:

Most Relevant Prior Art Citations for US11470595

1. US9826456B2

• Full Citation: US9826456B2, "Wireless local area network system and method for transmitting and receiving wireless packet using non-contiguous channel"
• Publication Date: 2017-11-21
• Filing Date: 2015-12-24
• Brief Description: This patent describes a wireless local area network system and method that utilize non-contiguous channels for transmitting and receiving wireless packets. Given the identical priority date (2015-12-24) and highly similar title to US11470595, this patent is almost certainly a foundational or closely related patent from the same patent family, likely disclosing the core concepts of non-contiguous channel communication. It likely covers the fundamental aspects of identifying non-contiguous channels and transmitting/receiving data over them.
• Potential Anticipation (35 U.S.C. § 102): US9826456B2 potentially anticipates claims 1, 7, 11, and 17 of US11470595. Specifically, the broad concepts of "receiving a wireless packet," "obtaining non-contiguous channel allocation information," "decoding the received packet based on the obtained non-contiguous channel allocation information," "performing a CCA of multiple channels," "transmitting a packet through at least one channel which is idle," and "signaling non-contiguous channel allocation information" would likely be disclosed. The distinction might lie in the specific method of signaling (e.g., "via a non-legacy preamble of the packet" as specified in US11470595, and particularly "via at least one of a subfield of HE-SIG-A and a subfield of HE-SIG-B" in dependent claims). If US9826456B2 discloses signaling non-contiguous channel allocation through a preamble, or more generally, through control information within a packet in a non-legacy format, it would broadly anticipate these independent claims. Further examination of US9826456B2's claims and specification would be required to determine if the "non-legacy preamble" or specific HE-SIG-A/B signaling methods are explicitly or inherently disclosed.

2. US20170064506A1

• Full Citation: US20170064506A1, "Wireless local area network system and method for transmitting and receiving wireless packet using non-contiguous channel"
• Publication Date: 2017-03-02
• Filing Date: 2016-08-26
• Brief Description: This published application describes a wireless local area network (WLAN) system and method for handling wireless packets over non-contiguous channels. Similar to US9826456B2, its title strongly suggests a direct overlap with the subject matter of US11470595. It is likely another related application in the same technical domain.
• Potential Anticipation (35 U.S.C. § 102): US20170064506A1 likely anticipates claims 1, 7, 11, and 17 of US11470595, particularly the general concepts of managing and using non-contiguous channels for packet transmission and reception. As a published application from 2017, it predates the filing date of US11470595 (2020-05-06, although US11470595 claims priority to 2015-12-24, which is earlier). If US20170064506A1 shares the same priority date as US11470595 (which it does not, its priority date is 2016-02-29), then its value as prior art depends on the specific disclosures. However, if it discloses the elements of US11470595's independent claims (e.g., reception/decoding of non-contiguous channel allocation, or CCA and signaling via non-legacy preamble), it would be anticipatory. Detailed examination of the specification and claims of US20170064506A1 would be necessary to confirm the extent of overlap.

3. US20190104618A1

• Full Citation: US20190104618A1, "Wireless local area network system and method for transmitting and receiving wireless packet using non-contiguous channel"
• Publication Date: 2019-04-04
• Filing Date: 2018-12-04
• Brief Description: This is another published application with a title nearly identical to US11470595, focusing on wireless communication using non-contiguous channels. It likely delves into methods and systems for handling such channel allocations.
• Potential Anticipation (35 U.S.C. § 102): Similar to the previous two, US20190104618A1 likely anticipates claims 1, 7, 11, and 17 of US11470595 by disclosing the core elements of non-contiguous channel operation. Since its publication date is prior to the filing date of US11470595, and its own priority date (2017-10-04) is later than that of US11470595 (2015-12-24), it is likely a continuation or related application that builds upon earlier work, but its disclosures are still relevant for an anticipation analysis if it publicly disclosed the claimed features before the priority date of US11470595. Given the family relationship, it would be important to determine if any features specifically claimed in US11470595 are distinct improvements over this prior application.

Important Note on Anticipation Analysis:
A complete anticipation analysis under 35 U.S.C. § 102 requires a detailed, side-by-side comparison of each element of a patent claim against the full disclosure (specification and claims) of a prior art reference. The brief descriptions provided above are based on the titles and general understanding of patent families, and thus the determination of "potential anticipation" is based on the strong likelihood of overlap in the fundamental concepts. To definitively determine anticipation, one would need to thoroughly review the full text of each cited prior art patent and its prosecution history.

The specific "non-legacy preamble" and "HE-SIG-A/B" signaling mentioned in the claims of US11470595 represent more granular details. Whether these specific signaling mechanisms are anticipated by the cited prior art would depend on their explicit or inherent disclosure within those documents. Given that US9826456B2 shares the exact priority date and a very similar title, it is highly probable that it discloses many of the core mechanisms, and subsequent dependent claims in US11470595 might claim specific implementations or refinements of those core ideas.

The current date is April 26, 2026. The patent US11470595 is titled "Wireless communication method and wireless communication terminal, which use discontinuous channel." The priority date for this patent is 2015-12-24.

The patent addresses the challenge of efficiently signaling non-contiguous channel allocation information in a high-density, high-performance wireless local area network (WLAN) environment, particularly in "next-generation wireless LAN standards" after IEEE 802.11ac and 802.11ad.

The core aspects of the invention, as gleaned from the "Definitions" section, include:

1. A wireless communication method and terminal that receive a wireless packet, obtain non-contiguous channel allocation information, and decode the packet based on this information.
2. A base wireless communication terminal (e.g., an Access Point or AP) that performs Clear Channel Assessment (CCA) of multiple channels for wideband packet transmission, transmits a packet through at least one idle channel, and signals non-contiguous channel allocation information via a non-legacy preamble (e.g., HE-SIG-A and/or HE-SIG-B) of the packet.
3. Specific signaling mechanisms, such as:
   • Indicating non-contiguous channel allocation information via a subfield of HE-SIG-A and/or HE-SIG-B, potentially indicating unassigned channels in 20 MHz units.
   • Using a bandwidth field of HE-SIG-A to indicate total bandwidth and channels to be "punctured" (not used) within that bandwidth.
   • Using a resource unit (RU) allocation field of HE-SIG-B to indicate specific RUs not assigned to a user (e.g., 242-tone, 484-tone, 996-tone RUs) through a predetermined index, or by using a Null STA ID in a user field corresponding to a specific RU.
   • A combination of the HE-SIG-A bandwidth field and HE-SIG-B RU allocation field for signaling.
   • Including a "C26 field" in the HE-SIG-B (for 80 MHz or more bandwidths) to indicate whether a user is allocated to a center 26-tone RU of 80 MHz.

Prior Art References (as described in the patent text):

The patent's "Definitions" section describes several IEEE 802.11 standards, all of which predate the patent's priority date of 2015-12-24, and thus constitute prior art:

• IEEE 802.11: The initial wireless LAN technology.
• IEEE 802.11a/b/g: Standards supporting various frequency bands (2.4 GHz, 5 GHz) and data rates, introducing OFDM technology.
• IEEE 802.11n: Introduced High Throughput (HT) and Multiple-Input Multiple-Output (MIMO) technology to increase speed and reliability.
• IEEE 802.11ac: Supports "wide bandwidth (80 to 160 MHz) in the 5 GHz frequencies" and "multi-user MIMO" (MU-MIMO), extending concepts from 802.11n.
• IEEE 802.11ad: Uses a 60 GHz band for very high speeds over short distances.
  The patent also describes the fundamental "carrier sense multiple access (CSMA)/collision avoidance (CA) method" including Clear Channel Assessment (CCA) as used in wireless LAN communication (FIG. 6).

Obviousness Analysis under 35 U.S.C. § 103:

A person having ordinary skill in the art (PHOSITA) at the priority date of 2015-12-24 would have been actively involved in developing "next-generation wireless LAN standards" to provide "high-efficiency and high-performance wireless LAN communication technology in a high-density environment." This context provides a strong motivation to combine existing technologies to address known problems in WLANs.

Combination of Prior Art: IEEE 802.11ac + IEEE 802.11 (CCA) + General Principles of WLAN Signaling

Motivation to Combine:
IEEE 802.11ac taught the use of wide bandwidths (80 MHz, 160 MHz) for higher throughput and introduced Multi-User MIMO (MU-MIMO) for multi-user transmissions. However, in dense wireless environments, it is common for portions of these wide channels to be busy due to other transmissions, as detected by the standard Clear Channel Assessment (CCA) mechanisms of IEEE 802.11. The patent itself highlights the inefficiency of traditional approaches, where a busy secondary channel might significantly reduce the available bandwidth or delay transmission (as illustrated in FIG. 18).

A PHOSITA, aiming to optimize spectrum utilization and maintain high throughput in such scenarios (a stated goal for next-generation WLANs), would be motivated to find ways to transmit even when parts of a wide channel are unavailable. This would naturally lead to considering the use of non-contiguous channel segments.

Obviousness of the Solution:

1. Using Non-Contiguous Channels: Given that wider channels are often formed by aggregating 20 MHz segments (e.g., 40 MHz is two 20 MHz, 80 MHz is four 20 MHz), and the basic CCA mechanism (from IEEE 802.11) identifies individual channels as busy or idle, it would be an obvious design choice to "puncture" (avoid using) only the busy 20 MHz segments within a desired wideband transmission, and still utilize the remaining available 20 MHz segments, even if they become non-contiguous. This extends the concept of dynamic bandwidth operation (FIG. 18(a)) by allowing greater flexibility in channel selection beyond strictly contiguous segments, improving channel utilization as shown in FIGS. 19(c), 19(d), and 20.

2. Signaling Non-Contiguous Channel Allocation Information via Non-Legacy Preamble:

   • Preamble Evolution: The evolution of IEEE 802.11 standards consistently demonstrates the practice of adding new signaling fields to preambles (e.g., HT-SIG in 802.11n, VHT-SIG in 802.11ac) to convey control information for new features. The patent explicitly shows the shift from "legacy PPDU" to "non-legacy PPDU" formats, which include HE-SIG-A and HE-SIG-B (FIG. 10). Thus, placing new control information related to non-contiguous channel usage into these evolving preamble fields would be an obvious engineering decision.
   • Bandwidth Field Augmentation (HE-SIG-A): IEEE 802.11ac already utilized a "bandwidth field" to indicate the total channel width (e.g., 20, 40, 80, 160 MHz). For a PHOSITA implementing non-contiguous channel usage, extending this existing field to additionally indicate which specific 20 MHz segments within the total allocated bandwidth are being "punctured" (i.e., unassigned or unused) would be an obvious modification. The patent describes this, for example, by indicating "unassigned channel information in units of 20 MHz."
   • Resource Unit Allocation Field and Null STA ID (HE-SIG-B): The patent references the use of "resource units (RUs)" (e.g., 26-tone, 52-tone, 106-tone) for subchannel-based access and describes the HE-SIG-B as containing an "RA field" (resource unit allocation) and "user specific field" to indicate resource unit partitions and assigned STAs. The patent further explicitly states that "a predetermined Null STA ID may be contained in user field(s) corresponding to the remaining resource unit(s) in which data transmission is not performed." Extending this known mechanism of identifying unassigned RUs using a "Null STA ID" or specific indices in the RA field to signify RUs (or 20 MHz channels, which are aggregations of RUs) that are "punctured" due to being busy would be a straightforward application of existing signaling concepts.
   • Combination of HE-SIG-A and HE-SIG-B: The concept of using both a higher-level signaling field (HE-SIG-A) for broad allocation information (e.g., total bandwidth and primary puncturing) and a lower-level field (HE-SIG-B) for finer-grained or supplementary information (e.g., "additional puncturing information") is a common and obvious design pattern in communication protocols.

3. C26 Field for Center 26-tone RU: Given the explicit definition of specific RU sizes (e.g., 26-tone, 52-tone, 106-tone) and their allocation, it would be an obvious engineering refinement to include a dedicated field (like the 1-bit "C26 field") in the HE-SIG-B to signal the status of a particularly significant RU, such as a "center 26-tone RU of 80 MHz." Such specific signaling could be motivated by particular regulatory requirements, spectral mask considerations, or performance optimizations for centrally located resource units within wider channels.

Conclusion:
Considering the widespread knowledge of wideband communication (IEEE 802.11ac), fundamental channel access mechanisms (IEEE 802.11 CCA), and the established practice of enhancing preamble signaling in evolving WLAN standards, a PHOSITA would have been motivated to develop methods for flexible spectrum utilization in congested environments. The idea of transmitting over non-contiguous channels by puncturing busy segments and signaling this information via existing or extended fields in the "non-legacy" preamble (HE-SIG-A and HE-SIG-B) using techniques like expanded bandwidth fields, resource unit allocation fields, or Null STA IDs, would have been obvious. The addition of a specific signaling field for a "center 26-tone RU" is an obvious engineering optimization within this broader framework. Therefore, the claimed invention in US11470595, when viewed through the lens of these prior art references and the motivations of a PHOSITA, would have been obvious under 35 U.S.C. § 103.