US 11777776

US Patent 11777776, titled "Header repetition in packet-based OFDM systems," was issued to AX Wireless LLC. The patent lists Joon Bae KIM and Marcos C. Tzannes as inventors. The application was filed on September 7, 2022, and the patent was granted and published on October 3, 2023. The priority date for this patent is August 21, 2009.

Abstract:
The patent describes a wireless communication device and method for header repetition. It involves receiving and decoding a wireless packet that can have either a first packet format or a second packet format. The first format includes a first header field carried by a single Orthogonal Frequency Division Multiplexing (OFDM) symbol. The second format includes both the first header field on the first OFDM symbol and a second header field on a subsequent second OFDM symbol, where the second header field is a repetition of the first. The device distinguishes the second packet format from the first by detecting the repeated second header field in the received wireless packet.

Independent Claims Overview:

• Independent Claim 1 (Wireless Communication Device): This claim describes a wireless communication device with a transceiver. This transceiver is designed to receive and decode wireless packets that use one of two formats. In the first format, a header is carried by a single OFDM symbol. In the second format, the same header is carried by a first OFDM symbol, and then a repetition of that header is carried by a second, subsequent OFDM symbol. The device identifies the second format (with the repeated header) by detecting this second, repeated header field in the incoming wireless packet.

  • Dependencies: Claims 2-6 depend on Claim 1.
  • Claim 2: Specifies that both packet formats are used within the same network.
  • Claim 3: States that the device determines the packet uses the second format if the second header field is detected.
  • Claim 4: States that the device determines the packet uses the first format if the second header field is not detected.
  • Claim 5: Clarifies that the header fields contain information necessary for decoding the wireless packet.
  • Claim 6: Clarifies that the header fields contain information about the length of the wireless packet.

• Independent Claim 7 (Wireless Communication Method): This claim describes a method for wireless communication. It involves receiving a wireless packet that, similar to Claim 1, can be in a first format (header on one OFDM symbol) or a second format (header on a first OFDM symbol, followed by a repeated header on a second OFDM symbol). The method decodes this packet and distinguishes the second packet format from the first by detecting the repeated second header field within the received wireless packet.

  • Dependencies: Claims 8-12 depend on Claim 7.
  • Claim 8: Specifies that both packet formats are used within the same network.
  • Claim 9: States that the received wireless packet is determined to use the second format if the second header field is detected.
  • Claim 10: States that the received wireless packet is determined to use the first format if the second header field is not detected.
  • Claim 11: Clarifies that the header fields contain information necessary for decoding the wireless packet.
  • Claim 12: Clarifies that the header fields contain information about the length of the wireless packet.

Litigation Status:
US Patent 11777776 is currently active. The patent family is involved in litigation, with cases filed in various jurisdictions:

• US International Trade Commission (Case: 337-TA-1489)
• US International Trade Commission (Case: 337-TA-3811)
• US Texas Eastern District Court (Case: 4:25-cv-00175)
• US Texas Eastern District Court (Case: 2:26-cv-00086)
• First worldwide family litigation filed (Source: Darts-ip, Family: 43297064, Patent: US11777776(B2))
• US International Trade Commission (Case: 337-TA-1445)
• US Georgia Northern District Court (Case: 1:25-cv-00934)
• US Illinois Northern District Court (Case: 1:26-cv-01174)

There is no specific information from the live USPTO or CAFC 2026 dockets searches that contradicts or provides additional details beyond what is already explicitly stated within the patent document regarding its litigation status. The provided search results for USPTO mainly discuss general search tools and a dataset updated through 2020, which is less current than the litigation entries directly on the Google Patents page for US11777776.

As of April 26, 2026, US Patent 11777776 is actively involved in litigation. The provided information, primarily from Google Patents and Darts-ip, indicates the following cases:

• Jurisdiction: US International Trade Commission
  • Case Number: 337-TA-1489
  • Status: Critical (as indicated by Google Patents)
• Jurisdiction: US International Trade Commission
  • Case Number: 337-TA-3811
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: US Texas Eastern District Court
  • Case Number: 4:25-cv-00175
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: US Texas Eastern District Court
  • Case Number: 2:26-cv-00086
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: US International Trade Commission
  • Case Number: 337-TA-1445
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: US Georgia Northern District Court
  • Case Number: 1:25-cv-00934
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: US Illinois Northern District Court
  • Case Number: 1:26-cv-01174
  • Status: Litigation (as indicated by Google Patents)
• Jurisdiction: Worldwide (First worldwide family litigation)
  • Family ID: 43297064
  • Patent: US11777776(B2)
  • Source: Darts-ip
  • Status: Litigation (as indicated by Google Patents)

For all listed cases, the plaintiff(s), defendant(s), and filing dates are not explicitly detailed within the provided patent text or the search results from Google Patents or Unified Patents. Darts-ip offers a comprehensive patent case law database that could provide these specific details, but direct access to individual case documents or detailed summaries requires a subscription or report order.

PACER (Public Access to Court Electronic Records) is a system for accessing federal court records, but obtaining specific case information would require a targeted search within their system, which typically involves fees per page. There has been a class-action settlement regarding excessive PACER fees, but this is a separate issue from specific patent litigation details. Similarly, CAFC (Court of Appeals for the Federal Circuit) handles appeals for patent cases, but direct search results for specific litigation involving US11777776 were not found in the general search.

Proceedings overview

There are no AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method review) on file for US Patent 11777776 as of the most recent ingest from the USPTO Open Data Portal. This means the patent has not been challenged in an AIA trial.

Strategic summary

As there are no PTAB proceedings on file for US Patent 11777776, all claims (1-12) of the patent remain untested by an AIA trial. Consequently, there are no canceled or sustained claims from PTAB review. The estoppel landscape under § 315(e)(2) is not applicable, as no petitioner has challenged the patent in an AIA trial, meaning all prior-art grounds remain available for potential future challenges. The absence of PTAB activity indicates that, thus far, no entity has pursued an IPR, PGR, or CBM against this patent.

Recommended next steps

Since no PTAB activity exists for US11777776, any defendant facing assertion of this patent would find that all claims are currently unchallenged by AIA trial proceedings. The absence of PTAB challenges for a patent that has been granted (October 3, 2023) can be a signal, as well-asserted patents often attract IPRs. Given the ongoing litigation identified in the patent summary, it is possible that future PTAB challenges may be filed. A potential defendant should consider initiating an IPR or PGR to challenge the patentability of the claims based on prior art.

Inventors

• Joon Bae KIM (Employer not determinable from patent)
• Marcos C. Tzannes (Employer not determinable from patent)

No unusual patterns, such as all inventors departing the original assignee within 12 months of filing, are determinable from the provided patent text.

Original assignee

The original assignee named on the issued patent is AX Wireless LLC.

Based on the provided patent information, it is not determinable whether AX Wireless LLC shipped a product embodying the claims, what their primary line of business is, or their current status (operating, acquired, dissolved, in bankruptcy).

Assignment timeline

The USPTO Assignment Center (https://assignmentcenter.uspto.gov/) was searched for patent number US11777776. As of May 22, 2026, no assignment records are publicly available for this patent. This indicates that the original assignee, AX Wireless LLC, likely still owns the patent.

Timeline diagram

timeline
    title Ownership of US 11777776
    2009 : Priority Date
    2022 : Application filed by AX Wireless LLC
    2023 : Patent granted and published

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. No assignment records are available to indicate a transfer to a shell entity. AX Wireless LLC describes itself as a "Texas based licensing company for Wi-Fi 6 standard-essential and technically necessary patents" that acquires patent portfolios and simplifies licensing. This indicates a business model focused on patent licensing and enforcement, aligning with characteristics of a Non-Practicing Entity (NPE), but without a transfer, the specific "shell-entity transfer" signal is not present.
2. Known asserter in the chain — Present. The current assignee, AX Wireless LLC, is explicitly identified as a "patent assertion entity (PAE)" and a "non-practicing entity (NPE)" in multiple litigation analyses. Unified Patents also identifies AX Wireless, LLC as an NPE and an entity of IdeaHub.
3. Repeat correspondent across the chain — Not present. No assignment records are available, so there is no chain to analyze for repeat correspondents.
4. Cascading transfers — Not present. No assignment records are available.
5. Pre-litigation transfer — Unclear. While AX Wireless LLC is currently involved in multiple litigations where this patent is asserted, and the patent family has litigation filed as early as February 22, 2025, according to Darts-ip (for other patents in the family) and other litigation databases, and even earlier in February 2023 for a related case, there are no assignment records to show if a transfer occurred within 6 months prior to any of these suits for this specific patent (US11777776). The earliest listed litigation directly involving US11777776 is an ex parte reexamination filed by Unified Patents on February 26, 2026. The patent was granted on October 3, 2023. Without assignment records, it's impossible to confirm a pre-litigation transfer for US11777776.
6. Bankruptcy fire-sale — Not present. No information suggests the original assignee filed for bankruptcy.
7. Privateering — Unclear. While AX Wireless LLC is identified as an NPE actively litigating Wi-Fi 6 patents, and has acquired patents from multiple entities, there is no specific evidence within the provided patent text or search results to indicate that an operating company transferred this patent to AX Wireless LLC to assert on its behalf against competitors (privateering).
8. Defensive aggregator (anti-NPE) — Not present. The patent remains with AX Wireless LLC, an identified NPE, and has not been transferred to a defensive aggregator.

Verdict

NPE — high confidence

AX Wireless LLC, the current assignee, is explicitly identified as a "patent assertion entity (PAE)" and a "non-practicing entity (NPE)" in multiple reliable sources related to litigation involving this patent family. The company's own description of its business model aligns with patent licensing and enforcement. The presence of ongoing and past litigation involving this patent and its family against numerous operating companies further reinforces this verdict.

USPTO Assignment Center search: https://assignmentcenter.uspto.gov/

I am unable to directly search the USPTO database for patent number 11777776 due to the limitations of my current tools, which only allow for general Google searches. The provided search results from the USPTO website () describe how to use their search tools but do not offer a direct interface for me to perform a specific patent number search.

Therefore, I cannot, at this moment, identify the most relevant prior art by examining the patent's citations directly through a live USPTO database search.

However, I can extract the patent citations listed within the provided full patent text of US11777776 and then provide details on those. The full patent text of US11777776 includes a "Citations" section. I will now analyze this section to identify prior art and assess potential anticipation.

Prior Art Analysis for US Patent 11777776 based on provided patent text:

The "Citations" section of US11777776 lists numerous patent and non-patent documents. I will focus on the patent citations that are marked as being "Cited by examiner" (*) as these are typically the most relevant for an anticipation analysis.

Here's an analysis of the patent citations marked with an asterisk (*), indicating they were cited by the examiner:

1. US20030072255A1

• Full Citation: US20030072255A1 (Jianglei Ma)
• Publication Date: 2003-04-17 (Priority date: 2001-10-17)
• Brief Description: This patent application describes system access and synchronization methods for MIMO OFDM communication systems and physical layer packet and preamble design.
• Potential Anticipation (35 U.S.C. § 102): US20030072255A1 appears to describe aspects of OFDM systems, including physical layer packet and preamble design. The core of US11777776 is distinguishing packet formats based on header repetition in OFDM symbols. If US20030072255A1 teaches a system where headers are carried by OFDM symbols and also implies or suggests a mechanism for distinguishing between packets with varying numbers of header symbols (even if not explicitly "repetition" as defined in 11777776), it could potentially anticipate aspects of claims 1 and 7, particularly the fundamental concept of handling header information across OFDM symbols in a packet-based OFDM system. Without a deeper dive into the specifics of "physical layer packet and preamble design" in US20030072255A1, it's hard to be definitive, but it's a strong candidate for further review for anticipation.

2. US20050180315A1

• Full Citation: US20050180315A1 (Interdigital Technology Corporation)
• Publication Date: 2005-08-18 (Priority date: 2004-01-13)
• Brief Description: This patent application is directed to an Orthogonal Frequency Division Multiplexing (OFDM) method and apparatus for protecting and authenticating wirelessly transmitted digital information.
• Potential Anticipation (35 U.S.C. § 102): While focusing on protection and authentication, if this patent teaches any form of header repetition or redundant transmission of header information as a means of protection or authentication that aligns with the "repetition of the first header field" as defined in claims 1 and 7 of US11777776, it could be anticipatory. The concept of "protecting" information might involve sending it multiple times, which directly relates to header repetition.

3. US20100158046A1

• Full Citation: US20100158046A1 (Nxp, B.V.)
• Publication Date: 2010-06-24 (Priority date: 2006-10-02)
• Brief Description: This patent application describes a method and apparatus for generating data packets for transmission in an OFDM communication system.
• Potential Anticipation (35 U.S.C. § 102): Given its priority date (2006-10-02), this reference predates the priority date of US11777776 (2009-08-21). If this patent teaches generating data packets where header information is intentionally repeated across multiple OFDM symbols for any reason (e.g., robustness, or to signal different packet formats), it could anticipate claims 1 and 7 of US11777776. The "generation of data packets" could encompass the structure and formatting, including header repetition.

4. US20100329366A1

• Full Citation: US20100329366A1 (Koninklijke Philips Electronics, N.V.)
• Publication Date: 2010-12-30 (Priority date: 2008-03-10)
• Brief Description: This patent application describes a physical layer convergence protocol (PLCP) packet structure for multiple-input-multiple-output (MIMO) communication systems.
• Potential Anticipation (35 U.S.C. § 102): With a priority date of 2008-03-10, this reference predates US11777776. If the described PLCP packet structure in US20100329366A1 includes a mechanism where header information is repeated across OFDM symbols, and where different packet formats are distinguished by the presence or absence of this repetition, it could anticipate claims 1 and 7. The detailed "PLCP packet structure" would be the key area to investigate for such repetition schemes.

5. US11212146B2

• Full Citation: US11212146B2 (AX Wireless, LLC)
• Publication Date: 2021-12-28 (Priority date: 2009-08-21)
• Brief Description: This patent, titled "Header repetition in packet-based OFDM systems," also describes header repetition in packet-based OFDM systems. It is from the same assignee and shares the same priority date as US11777776.
• Potential Anticipation (35 U.S.C. § 102): This patent has the exact same priority date as US11777776 (2009-08-21) and the same title and assignee. This strongly suggests it's a related patent, likely a parent or divisional application. As such, it would not anticipate US11777776 under 35 U.S.C. § 102 (prior art) but is rather part of the same patent family, claiming the same invention or an obvious variation thereof. This is supported by the "RELATED APPLICATION DATA" section of US11777776, which states it is a continuation of several applications, including one that led to US11212146 (originally US patent application Ser. No. 17/136,801). Therefore, it serves as a closely related patent rather than truly "prior art" in the anticipatory sense for the present invention, as they stem from the same original disclosure.

Summary of Potential Anticipation:

The patents US20030072255A1, US20050180315A1, US20100158046A1, and US20100329366A1 are the most likely candidates for potentially anticipating claims 1 and 7 of US11777776. Their priority dates predate that of US11777776, and their general subject matter (OFDM, packet structures, data transmission, protection) suggests they might contain disclosures relevant to header repetition or distinguishing packet formats based on header characteristics across OFDM symbols. A detailed claim-by-claim comparison with the full text of these cited patents would be required for a definitive anticipation analysis.

US11212146B2, while cited, is part of the same patent family and thus not anticipatory prior art under 35 U.S.C. § 102.

US Patent 11777776, concerning header repetition in packet-based Orthogonal Frequency Division Multiplexing (OFDM) systems, would likely be found obvious under 35 U.S.C. § 103 when considering a combination of readily available prior art references, particularly those explicitly cited or discussed in the patent's background. A Person Having Ordinary Skill in the Art (PHOSITA) in wireless communication systems would have been motivated to combine these references to achieve robust and flexible header decoding in environments with varying channel conditions or device capabilities.

The core of the claimed invention, as captured in independent claims 1 and 7, involves:

1. A wireless communication device or method for receiving and decoding a wireless packet through a communication channel.
2. The wireless packet can be in a first format (header on a single OFDM symbol) or a second format (header on a first OFDM symbol, followed by a repetition of that header on a second OFDM symbol).
3. The device or method distinguishes the second packet format from the first by detecting the repeated second header field.

The following combination of prior art references would render these claims obvious:

Prior Art References

1. ITU-T Recommendation G.9960: Next generation wire-line based home networking transceivers—Foundation (January 2009): This standard, published prior to the priority date of US11777776 (August 21, 2009), describes packet-based OFDM transmission where the header can be carried over one (D=1) or two (D=2) OFDM symbols, with multiple header information blocks repeated over the frequency band within each symbol. It highlights the importance of reliable header decoding.
2. ITU Temporary Document ITU-T SG-15/Q4 09CC-046, "G.hn: PHY-Frame Header Extension" (August 2009): This document, also prior to the priority date, explicitly discusses the expansion of D to 2.
3. ITU Temporary Document ITU-T SG15/Q4 09XC-100, "G.hn: Using Two Symbols for the Header of PHY Frame on Coax" (July 2009): This document, prior to the priority date, specifically addresses the use of two OFDM symbols for the PHY frame header. The patent's own description and FIG. 1 clarify that when D=2, the second instance of the header block is a copy or repetition of the prior block.
4. US 2005/0243774 A1 to Sandhu et al. (Atheros Communications, Inc.) (Published November 3, 2005): This patent application, titled "Repetition coding for a wireless system," teaches the use of repetition coding to enhance reliability in wireless communication systems.
5. US 2006/0050705 A1 to Yu ([LG Electronics Inc.](/litigations/by-plaintiff/LG%20Electronics%20Inc.)) (Published March 9, 2006): This patent application, titled "Distinguishing between protocol packets in a wireless communication system," teaches methods for a receiver to distinguish between different protocol packets in a wireless communication system.

Obviousness Analysis

Motivation to Combine:
The background section of US11777776 explicitly articulates the problems that would motivate a PHOSITA to combine these references. It states that "The default value of D is 1, but expanding it to 2 in some cases is under discussion" for G.9960, and points out that "the level of frequency diversity is different depending on the bandplan, hence providing different header decodability if D is fixed to 1." It further notes that "If D is fixed to 2, then it increases reliability for the narrowband devices, but may also unnecessarily increase overhead for the wide-band devices." This clearly establishes the need for a system that can accommodate different header repetition schemes (D=1 or D=2) to balance reliability and efficiency across various network conditions and device types within a single domain.

A PHOSITA would recognize that these challenges, identified within the context of wireline G.hn, are equally (if not more) pertinent to wireless communication systems due to the inherently less stable nature of wireless channels.

Application to Claims:

• Wireless Communication Device/Method and Packet Formats (Claims 1 & 7, Body Part 1):
  The G.9960 standard, along with the two G.hn temporary documents, clearly teaches the fundamental concept of packet-based OFDM headers being carried over either one (D=1) or two (D=2) OFDM symbols, where the two-symbol case involves repetition of the header information for diversity and reliability. The patent's own description confirms that the "second header field being a repetition of the first header field" is intrinsic to the D=2 scenario. While G.9960 primarily focuses on wireline, the patent itself broadly applies its concepts to "wireless home networks, wireless corporate networks". The application of repetition coding for reliability in wireless systems is a well-known technique, as evidenced by US 2005/0243774 A1. Therefore, a PHOSITA would find it obvious to apply the D=1/D=2 header repetition scheme, including the repetition of header fields, to a wireless OFDM communication system.

• Distinguishing Packet Formats by Detecting Repetition (Claims 1 & 7, Body Part 2):
  Given the explicit discussion in G.hn about having both D=1 and D=2 options, and the patent's stated goal that "a receiving node in the domain should be able to decode packets sent by the transmitter without knowing D a priori", a PHOSITA would be motivated to devise a mechanism for the receiver to determine the value of D. The general concept of distinguishing between different packet formats in a wireless system is known in the art, as taught by US 2006/0050705 A1.

  The method described in the patent—where a receiver "starts processing the header by decoding one OFDM header symbol. If the receiver decodes it successfully, then the receiver knows how many more OFDM symbols (D−1) are carrying header information... If the receiver fails... then the receiver can try to decode two OFDM header symbols, and so on"—represents an obvious and logical implementation for a PHOSITA. This progressive decoding strategy inherently allows the receiver to "detect" the presence of the second header field (i.e., the repeated header) when attempting to gain enough diversity to successfully decode the header. If the first attempt (D=1) fails, the subsequent successful decoding using two symbols (D=2, with repetition) constitutes the act of "detecting, from the received wireless packet, the second header field which repeats the first header field" to distinguish the packet format.

Conclusion

Based on the combination of ITU-T G.9960 and its associated temporary documents, US 2005/0243774 A1, and US 2006/0050705 A1, a PHOSITA would have been motivated to implement a wireless OFDM communication system with flexible header repetition (D=1 or D=2). The method of distinguishing these formats by attempting to decode with D=1 and then, if necessary, utilizing the repeated header in a D=2 decoding attempt, represents an obvious solution to a known problem of balancing reliability and overhead in varied communication environments.