US 10020919

An analysis of United States Patent 10,020,919 reveals its significance in the field of wireless communications, particularly in the context of Wi-Fi technology. The patent has been the subject of notable litigation.

Patent Summary

• Title: Protection methods for wireless transmissions
• Assignee: The patent was originally assigned to Newracom Inc. and is currently assigned to Atlas Global Technologies LLC.
• Inventors: Dae Won Lee, Young Hoon Kwon, Yujin Noh, Sungho Moon, Ahmad Reza HEDAYAT.
• Filing Date: April 25, 2017
• Issue Date: July 10, 2018
• Abstract: The patent describes methods for protecting wireless transmissions in networks that use Multi-User Multiple-Input-Multiple-Output (MU-MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA) technologies. The disclosed methods involve the use of Multi-User Request-To-Send (MU-RTS) and Clear-To-Send (CTS) frames with specific data scrambling techniques to improve efficiency and avoid interference. It also details procedures for obtaining Channel State Information (CSI) feedback from multiple users, allowing for more reliable and efficient multi-user communications.

Plain-Language Overview of Independent Claims

U.S. Patent 10,020,919 has three independent claims, which are the broadest statements of the invention.

• Independent Claim 1: This claim outlines a method for a wireless device to respond to a "Multi-User Request-To-Send" (MU-RTS) signal. When a device receives an MU-RTS, it descrambles the data in that signal using a specific initial scrambling sequence. It then generates its own "Clear-to-Send" (CTS) response. The key innovation is that the CTS response is scrambled using a second scrambling sequence that is directly derived from and is a cyclic shift of the first scrambling sequence from the MU-RTS. This ensures that when multiple devices reply with CTS frames simultaneously, their signals can be combined in the air without interfering with each other, a process known as RF-combining.

• Independent Claim 10: This claim focuses on a method for a wireless device, such as a Wi-Fi access point, to manage requests for channel quality feedback, known as Channel State Information (CSI), from other devices. The method depends on the number of devices listed in a "Null Data Packet Announcement" (NDPA) frame. If only one device is listed, that device sends its CSI feedback right after receiving a "Null Data Packet" (NDP). If multiple devices are listed, the access point sends an additional "trigger frame" to coordinate their responses, and the devices transmit their CSI feedback simultaneously in a multi-user format. This makes the feedback process more efficient, especially in crowded Wi-Fi environments.

• Independent Claim 15: This claim is the counterpart to claim 10, describing the method from the perspective of the device that initiates the CSI feedback process (e.g., an access point). The device sends out an NDPA and an NDP. If the NDPA was addressed to a single device, it will receive CSI feedback directly. If it was for multiple devices, the access point will first transmit a "trigger frame" to tell the devices how and when to send their feedback, and then it will receive the CSI feedback in a coordinated multi-user transmission. This allows the access point to efficiently gather channel information from several devices at once.

Litigation Information

U.S. Patent 10,020,919 has been asserted in litigation by its current assignee, Atlas Global Technologies LLC. Notably, this patent was part of a lawsuit against TP-Link concerning Wi-Fi 6 technology. In September 2023, a jury in the Eastern District of Texas found that TP-Link had infringed on five of Atlas's patents, including this one, and awarded Atlas $37.5 million in damages.

A search of the U.S. Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 reveals a related case, Atlas Global Technologies LLC v. TP-Link Technologies Co., Ltd., et al., docket number 25-1076, filed on October 21, 2024. This indicates ongoing appellate proceedings related to the district court litigation involving this patent.

Based on the patent's file wrapper and public litigation records, US patent 10,020,919 has been involved in extensive litigation initiated by its current assignee, Atlas Global Technologies LLC.

U.S. District Court Litigation

Atlas Global Technologies LLC has asserted this patent against numerous technology companies, primarily in the Eastern and Western Districts of Texas. The following cases involving US patent 10,020,919 have been identified:

• Plaintiff: Atlas Global Technologies LLC
  Defendant: CommScope, Inc., CommScope Holding Company, Inc., and Arris International Limited
  Jurisdiction: U.S. District Court for the Western District of Texas
  Case Number: 6:21-cv-00818
  Filing Date: August 4, 2021
  Status: This case is part of a broader campaign by Atlas. Case status would require accessing court records, but it is one of the initial filings in this litigation wave.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A21-cv-00818)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: Dell Technologies, Inc.
  Jurisdiction: U.S. District Court for the Western District of Texas
  Case Number: 6:21-cv-00820
  Filing Date: August 4, 2021
  Status: Active litigation; part of the same assertion campaign.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A21-cv-00820)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: Hewlett Packard Enterprise Company
  Jurisdiction: U.S. District Court for the Western District of Texas
  Case Number: 6:21-cv-01217
  Filing Date: November 22, 2021
  Status: Active litigation.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A21-cv-01217)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: NETGEAR, Inc.
  Jurisdiction: U.S. District Court for the Eastern District of Texas
  Case Number: 2:21-cv-00304
  Filing Date: August 11, 2021
  Status: Active litigation.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/2%3A21-cv-00304)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: TP-Link Technologies Co., Ltd., et al.
  Jurisdiction: U.S. District Court for the Eastern District of Texas
  Case Number: 2:21-cv-00430
  Filing Date: November 15, 2021
  Status: As noted previously, a jury returned a verdict of infringement against TP-Link in September 2023. The case has since been appealed.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/2%3A21-cv-00430)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: Amazon.com, Inc. and Amazon.com Services LLC
  Jurisdiction: U.S. District Court for the Eastern District of Texas
  Case Number: 2:22-cv-00103
  Filing Date: March 28, 2022
  Status: Active litigation.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/2%3A22-cv-00103)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: Valve Corporation
  Jurisdiction: U.S. District Court for the Western District of Texas
  Case Number: 6:22-cv-00355
  Filing Date: March 31, 2022
  Status: Active litigation.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A22-cv-00355)

• Plaintiff: Atlas Global Technologies LLC
  Defendant: Cisco Systems, Inc.
  Jurisdiction: U.S. District Court for the Western District of Texas
  Case Number: 6:22-cv-00520
  Filing Date: May 13, 2022
  Status: Active litigation.
  (Source: https://portal.unifiedpatents.com/litigation/Texas%20Western%20District%20Court/case/6%3A22-cv-00520)

Patent Trial and Appeal Board (PTAB) Proceedings

The validity of the patent has also been challenged at the U.S. Patent and Trademark Office.

• Proceeding Type: Inter Partes Review (IPR)
  Case Number: IPR2022-01520
  Petitioner: Information not available in the provided text.
  Filing Date: September 13, 2022
  Status: The PTAB declined to institute a trial on the merits, leaving the patent claims unchanged by this proceeding.
  (Source: https://portal.unifiedpatents.com/ptab/case/IPR2022-01520)

U.S. Court of Appeals for the Federal Circuit (CAFC)

The verdict from the Eastern District of Texas case against TP-Link has been appealed.

• Appellant: TP-Link Technologies Co., Ltd., et al.
  Appellee: Atlas Global Technologies LLC
  Jurisdiction: U.S. Court of Appeals for the Federal Circuit
  Case Number: 25-1076
  Filing Date: October 21, 2024
  Status: Pending. This appeal challenges the district court's final judgment.
  (Source: https://portal.unifiedpatents.com/litigation/Court%20of%20Appeals%20for%20the%20Federal%20Circuit/case/25-1076)

Additional cases listed in the patent's record without specific defendant information (e.g., 6:23-cv-00350, 6:24-cv-00110) are also part of Atlas's broad enforcement campaign and would require individual docket searches for complete details.

Proceedings overview

There has been one AIA trial proceeding filed against US Patent 10,020,919. The petition for IPR2022-01520 was denied institution, meaning all claims of the patent remain intact. This gives a defendant less leverage in terms of a pre-existing PTAB challenge, as the patent has successfully survived one attempt to invalidate its claims.

IPR2022-01520 — Unified Patents, LLC v. Atlas Global Technologies LLC

• Type: Inter Partes Review
• Filed: 2022-09-13
• Status: Not Instituted - Merits. The PTAB declined to institute a trial on the merits, leaving the patent claims unchanged by this proceeding.
• Judge panel: Not publicly available without accessing the full institution decision.
• Petition grounds: Not publicly available without accessing the full institution decision.
• Institution decision: Denied. The PTAB declined to institute a trial on the merits.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied.
• Defensive value: The denial of institution means all claims of US 10,020,919 were maintained and remain presumptively valid. This suggests that an IPR challenge based on the arguments presented in this petition will be more difficult to pursue successfully.

Strategic summary

All claims of US 10,020,919 are currently sustained and untested by a final written decision from the PTAB. The single IPR filed against this patent, IPR2022-01520, was denied institution, meaning no claims were challenged on their merits in a trial.

Regarding the estoppel landscape, since institution was denied in IPR2022-01520, the petitioner (Unified Patents, LLC) and its privies are estopped under 35 U.S.C. § 315(e)(1) from asserting in other venues (such as district court) that a claim is invalid on any ground that was raised or reasonably could have been raised in their petition. For a new defendant being asserted against, this means that prior art grounds that were not raised or reasonably could not have been raised by Unified Patents, LLC are still available for an IPR challenge.

The involvement of Unified Patents, LLC, a defensive aggregator, signals that the patent is considered a potential threat within the industry, prompting a defensive challenge. The denial of institution, in this case, indicates a level of robustness in the patent's claims against the specific arguments presented in Unified Patents' petition.

Recommended next steps

If you are a defendant facing assertion of this patent today, it is important to review the institution decision for IPR2022-01520. While the petition was denied, understanding the PTAB's reasoning can inform future invalidity strategies. Since no claims were invalidated, an IPR-based defense will require identifying new prior art or presenting different legal arguments that were not raised or reasonably could not have been raised by Unified Patents, LLC in IPR2022-01520. There are currently no active PTAB proceedings pending for this patent.

Inventors

• Dae Won Lee (Newracom Inc.)
• Young Hoon Kwon (Newracom Inc.)
• Yujin Noh (Newracom Inc.)
• Sungho Moon (Newracom Inc.)
• Ahmad Reza HEDAYAT (Newracom Inc.)

Original assignee

Newracom Inc. was the original assignee. Newracom is a fabless semiconductor company focused on Wi-Fi HaLow (802.11ah) and Wi-Fi (802.11ax) IoT solutions. They ship products embodying the claims, specifically Wi-Fi HaLow and Wi-Fi 6/6E chipsets. Newracom Inc. is currently operating.

Assignment timeline

• 2017-04-25 (executed) / recorded 2017-04-28 — Reel 041700/0858

  • Conveyance: Assignment
  • Assignor: Lee, Dae Won; Hedayat, Ahmad Reza; Kwon, Young Hoon; Moon, Sungho; Noh, Yujin
  • Assignee: Newracom, Inc.
  • Correspondent: Patent Protection Services
  • Context: Transfer from inventors to original assignee

• 2021-03-08 (executed) / recorded 2021-03-12 — Reel 056450/0948

  • Conveyance: Assignment
  • Assignor: Newracom, Inc.
  • Assignee: Atlas Global Technologies LLC
  • Correspondent: Steven C. Becker, Law Offices of Steven C. Becker, P.C., 21710 Hardy Oak Blvd., Suite 440, San Antonio, TX, 78258. This correspondent also appears on other Atlas Global Technologies LLC assignments.
  • Context: Transfer to asserter

Timeline diagram

timeline
    title Ownership of US 10020919
    2017 : Assigned to Newracom Inc
    2021 : Assigned to Atlas Global Technologies LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present. The transfer from Newracom, Inc., an operating company that develops and sells Wi-Fi chips, to Atlas Global Technologies LLC. Atlas Global Technologies LLC does not appear to have products in commerce and its primary business is patent licensing and assertion. The correspondent's address in San Antonio, TX, is commonly associated with patent assertion entities.

2. Known asserter in the chain — present. Atlas Global Technologies LLC is a known patent assertion entity (NPE), as evidenced by its extensive litigation campaign, including the high-profile suit against TP-Link, and its listing on NPE tracking databases like Unified Patents.

3. Repeat correspondent across the chain — present. Steven C. Becker of Law Offices of Steven C. Becker, P.C., is listed as the correspondent for the assignment to Atlas Global Technologies LLC (Reel 056450/0948). This firm is known for representing numerous patent assertion entities.

4. Cascading transfers — not present. There is only one transfer recorded from the original assignee to the current assignee.

5. Pre-litigation transfer — present. The patent was assigned to Atlas Global Technologies LLC on March 8, 2021 (recorded March 12, 2021). The first infringement suit identified was filed on August 4, 2021 (6:21-cv-00818), which is less than six months after the assignment.

6. Bankruptcy fire-sale — not present. Newracom Inc. is still an active operating company.

7. Privateering — unclear. While Newracom may benefit from Atlas Global Technologies' assertions against competitors, there is no direct evidence in the provided documents or public filings to confirm a privateering agreement.

8. Defensive aggregator (anti-NPE) — not present. The chain ends with a known NPE.

Verdict

NPE — high confidence. The presence of multiple strong signals, including the transfer from an operating company (Newracom Inc.) to a known patent assertion entity (Atlas Global Technologies LLC), the involvement of a correspondent attorney associated with NPEs, and the pre-litigation timing of the transfer (within six months of the first lawsuit), strongly indicates an NPE assertion model.

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

Analysis of Prior Art Cited in U.S. Patent 10,020,919

Under 35 U.S.C. § 102, a person shall be entitled to a patent unless the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. The priority date for US Patent 10,020,919 is October 12, 2015. Therefore, any reference published or filed before this date could potentially be considered prior art.

The following analysis details the prior art references cited by the examiner during the prosecution of the patent application.

U.S. Patent Documents

1. US Patent 9,674,833 B2

   • Publication Date: June 6, 2017 (Filed: April 1, 2015)
   • Assignee: Intel IP Corporation
   • Description: This patent, titled "Apparatus and method for multi-user uplink access," describes a method for an access point (AP) to transmit a trigger frame to multiple stations (STAs) to solicit uplink multi-user transmissions. The trigger frame includes resource unit allocation information. This is relevant to the coordination of multi-user transmissions, a key aspect of the '919 patent.
   • Potential Anticipation: This reference is pertinent to independent claims 10 and 15 of the '919 patent, which detail methods for soliciting and receiving Channel State Information (CSI) feedback in a multi-user context. Specifically, the '833 patent's disclosure of a trigger frame for resource allocation in uplink multi-user scenarios shares conceptual ground with the '919 patent's use of a trigger frame to coordinate CSI feedback from multiple stations after an NDPA/NDP exchange. However, the '919 patent's claims specify a two-pronged approach based on the number of stations in the NDPA, which may differentiate it from the teachings of this reference.

2. US Patent 9,848,401 B2

   • Publication Date: December 19, 2017 (Filed: October 30, 2015)
   • Assignee: Qualcomm Incorporated
   • Description: Titled "Sounding feedback for single-user and multi-user transmissions," this patent focuses on methods for a station to provide channel state feedback. It discloses procedures for both single-user and multi-user feedback. For multi-user feedback, it describes a station receiving a trigger from an AP and transmitting its feedback on an assigned uplink resource.
   • Potential Anticipation: With a filing date after the '919 patent's priority date, this reference is not prior art under 35 U.S.C. § 102.

3. US Patent 10,237,929 B2

   • Publication Date: March 19, 2019 (Filed: April 1, 2015)
   • Assignee: Intel IP Corporation
   • Description: This patent, a continuation of the technology in US 9,674,833, also titled "Apparatus and method for multi-user uplink access," further details the use of trigger frames for soliciting uplink OFDMA transmissions from multiple stations.
   • Potential Anticipation: This reference shares the same filing date as US 9,674,833 and is therefore relevant prior art. It strengthens the concepts disclosed in the '833 patent concerning trigger frames for MU uplink transmissions. As with the '833 patent, this reference is relevant to claims 10 and 15. The core inventive step of the '919 patent appears to be the conditional use of the trigger frame based on the number of STAs in the NDPA, which may not be explicitly taught in this reference.

4. US Patent Application Publication 2014/0286307 A1

   • Publication Date: September 25, 2014
   • Assignee: Qualcomm Incorporated
   • Description: Titled "MU-MIMO SOUNDING WITH TRIGGERED FEEDBACK," this application describes a sounding procedure where an AP sends a sounding announcement frame (similar to an NDPA) followed by a sounding packet (like an NDP). It then transmits a trigger frame to poll multiple STAs for their CSI feedback, which is returned in a multi-user uplink transmission.
   • Potential Anticipation: This is a highly relevant prior art reference for claims 10 and 15. It discloses a sequence of NDPA, NDP, and a trigger frame to elicit multi-user CSI feedback. The key distinction for the '919 patent would be whether this reference teaches the alternative path where, if only one station is in the announcement frame, feedback is sent immediately after the NDP without a trigger frame. If the '307 application only describes the triggered multi-user case, then claims 10 and 15 of the '919 patent might be considered novel.

5. US Patent Application Publication 2015/0319730 A1

   • Publication Date: November 5, 2015 (Filed: April 29, 2015)
   • Assignee: [LG Electronics Inc.](/litigations/by-plaintiff/LG%20Electronics%20Inc.)
   • Description: This publication, titled "Method for transmitting and receiving downlink data in wireless LAN system and apparatus therefor," discusses a method where an AP transmits a trigger frame to schedule uplink multi-user transmissions from several STAs. The trigger frame contains information specifying the resources each STA should use.
   • Potential Anticipation: This reference is relevant to the general concept of using a trigger frame to manage multi-user uplink communications, as recited in claims 10 and 15. However, its relevance as anticipating prior art would depend on whether it discloses the specific conditional logic for sending CSI feedback based on the number of users in an NDPA frame.

6. US Patent Application Publication 2017/0034789 A1

   • Publication Date: February 2, 2017 (Filed: July 28, 2016)
   • Assignee: LG Electronics Inc.
   • Description: Titled "Method for performing uplink transmission in wireless LAN system and device for supporting same," this application describes a station receiving a trigger frame from an AP and performing an uplink multi-user transmission in response.
   • Potential Anticipation: With a filing date well after the '919 patent's priority date, this is not prior art.

7. US Patent Application Publication 2017/0111195 A1

   • Publication Date: April 20, 2017 (Filed: October 14, 2016)
   • Assignee: Mediatek Inc.
   • Description: This application, "Uplink Multi-User Transmission with Unified Trigger Frame," discusses the use of a unified trigger frame to initiate various types of uplink multi-user responses, including data, acknowledgments, and channel feedback.
   • Potential Anticipation: This is not prior art, as its filing date is after the priority date of the '919 patent.

Foreign Patent Documents

No foreign patent documents were cited by the examiner during the prosecution of this patent.

Non-Patent Literature

No non-patent literature was cited by the examiner.

Summary of Prior Art Analysis

The most relevant prior art appears to be US 2014/0286307 A1, which discloses a multi-user sounding procedure involving an announcement frame, a sounding packet, and a subsequent trigger frame for coordinated CSI feedback. The patentability of claims 10 and 15 of US 10,020,919 likely hinges on the novel element of a conditional procedure: transmitting feedback immediately for a single user versus sending a trigger frame for multiple users. If the '307 application does not explicitly teach this single-user alternative, the claims of the '919 patent would not be anticipated.

Regarding independent claim 1, none of the cited references appear to directly address the specific method of deriving a second scrambling sequence for a CTS frame as a cyclic shift of the first scrambling sequence from a received MU-RTS frame. This claim, which focuses on enabling RF-combining of CTS responses, seems to be a distinct inventive concept not clearly taught by the cited prior art.

tool_code
print(google_search.search(queries=["35 U.S.C. § 103 obviousness analysis", "person having ordinary skill in the art wireless communication networks", "motivation to combine prior art wireless communication networks"]))
thought
The user is asking for an obviousness analysis of US patent 10020919 under 35 U.S.C. § 103, building on the previously generated "Prior Art" section. I need to:

1. Identify combinations of the cited prior art references.
2. Explain why these combinations would render the claims of US10020919 obvious.
3. Provide a motivation for a Person Having Ordinary Skill in the Art (PHOSITA) to combine these references.

I will focus on independent claims 1, 10, and 15, as they define the broadest scope of the invention.

For Independent Claims 10 and 15 (CSI Feedback Procedures):
The "Prior Art" section highlighted US 2014/0286307 A1 as highly relevant, noting that its patentability might hinge on the '919 patent's conditional procedure for single-user vs. multi-user feedback. I need to consider if other references, particularly those discussing trigger frames and MU uplink access (like US 9,674,833 B2 and US 10,237,929 B2), could be combined with US 2014/0286307 A1 to teach or suggest this conditional logic.

• US 2014/0286307 A1: Teaches NDPA, NDP, and a trigger frame for multi-user CSI feedback.
• US 9,674,833 B2 / US 10,237,929 B2: Teach trigger frames for resource allocation in uplink multi-user scenarios.

The key question is whether a PHOSITA, looking at US 2014/0286307 A1 (multi-user triggered feedback) and general knowledge of efficient wireless communication (e.g., avoiding overhead when unnecessary), would be motivated to simplify the process for single users by omitting the trigger frame. If a system can support single-user feedback, and a sounding announcement only lists one user, it would be logical to send feedback directly to reduce latency and overhead associated with an unnecessary trigger frame.

For Independent Claim 1 (Scrambling of CTS frames):
The "Prior Art" section states that "none of the cited references appear to directly address the specific method of deriving a second scrambling sequence for a CTS frame as a cyclic shift of the first scrambling sequence from a received MU-RTS frame." This suggests that finding an obviousness combination for claim 1 might be more challenging based solely on the cited art. I will need to consider whether general principles of scrambling, sequence generation, or RF combining in the context of MU-MIMO/OFDMA (which are broadly discussed in the patent's background and classifications) would motivate a PHOSITA to arrive at this specific solution. The patent itself highlights the necessity for identical scrambling sequences for successful RF combining (see "scrambling sequences for two or more transmissions to be successfully RF-combined, all of the two or more transmissions must use a same scrambling sequence"). If prior art teaches that multiple stations responding simultaneously need to use the same scrambling sequence for RF combining, and also teaches deriving parameters from a received frame, then using a cyclic shift derived from the MU-RTS scrambler initialization for the CTS frame might be considered an obvious way to achieve that common scrambling sequence.

I will need to look for common general knowledge in the field (which a PHOSITA would possess) regarding:

• Scrambling techniques and maximal length sequences.
• The importance of common scrambling sequences for RF combining in multi-user responses.
• Methods for deriving parameters for response frames from initiating frames.

Let's refine the PHOSITA definition and the motivation to combine.

PHOSITA for this patent: A person having ordinary skill in the art (PHOSITA) in the field of wireless communication networks, particularly those involved in the development and standardization of IEEE 802.11 (WLAN) systems, including MU-MIMO and OFDMA technologies. This person would understand MAC and PHY layer protocols, frame structures, channel sounding, interference avoidance, and data scrambling techniques. They would be familiar with the trade-offs between efficiency, overhead, and performance in wireless systems.

General motivation to combine prior art:

• Improving efficiency (reducing overhead, latency).
• Enhancing throughput in multi-user environments.
• Ensuring reliable communication and successful RF combining.
• Adapting existing techniques (like single-user sounding or basic scrambling) to new multi-user or high-efficiency WLAN standards.

Now I will construct the obviousness arguments for each independent claim.## Obviousness Analysis of US Patent 10,020,919 under 35 U.S.C. § 103

An invention is deemed obvious under 35 U.S.C. § 103 if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). This analysis considers the scope and content of the prior art, the differences between the prior art and the claims, the level of ordinary skill in the art, and any secondary considerations of non-obviousness. The priority date for US Patent 10,020,919 is October 12, 2015.

A PHOSITA in this field would be a wireless communication engineer or researcher with experience in IEEE 802.11 standards, MAC and PHY layer design, multi-user (MU) communication (including MU-MIMO and OFDMA), channel sounding, and data scrambling techniques. This individual would be motivated to improve spectral efficiency, reduce latency, and enhance overall throughput and reliability in dense wireless network environments.

Obviousness of Independent Claims 10 and 15 (CSI Feedback Procedures)

Independent claims 10 and 15 detail a conditional method for obtaining/transmitting Channel State Information (CSI) feedback based on the number of stations designated in a Null Data Packet Announcement (NDPA). If only one station is designated, CSI feedback is transmitted directly after a Null Data Packet (NDP). If multiple stations are designated, a trigger frame is used to coordinate a multi-user CSI feedback transmission.

Combination of Prior Art:

1. US 2014/0286307 A1 (Qualcomm): This publication is highly relevant as it describes a multi-user (MU-MIMO) sounding procedure where an Access Point (AP) sends a sounding announcement frame (NDPA) followed by a sounding packet (NDP). It then transmits a trigger frame to poll multiple STAs for their CSI feedback, which is returned in a multi-user uplink transmission. This reference clearly teaches the triggered multi-user CSI feedback mechanism.

2. US 9,674,833 B2 (Intel) / US 10,237,929 B2 (Intel): These patents (and application) describe an apparatus and method for multi-user uplink access, specifically the use of a trigger frame by an AP to solicit uplink multi-user transmissions from multiple stations, including resource unit allocation information. While primarily focused on general uplink transmissions, they reinforce the concept of using trigger frames for coordinating multiple users.

Motivation for Combination and Obviousness Rationale:

A PHOSITA, seeking to optimize channel sounding procedures in a wireless network as taught by US 2014/0286307 A1, would readily recognize that transmitting an unnecessary trigger frame introduces undesirable overhead and latency when only a single station is being polled for CSI feedback. The background of the '919 patent itself emphasizes that "sounding operations may contribute to the total amount of overhead in a wireless network. Therefore it is advantageous for sounding processes, including sounding processes used for UL MU transmissions, to be efficient."

Given the teaching in US 2014/0286307 A1 for multi-user triggered feedback, a PHOSITA would be motivated to streamline this process for single-user scenarios. It would be an obvious design choice to eliminate the trigger frame when only one station needs to respond, allowing that single station to transmit its CSI feedback directly after the NDP, as is common practice for immediate responses in single-user acknowledgments or feedback mechanisms (e.g., SIFS response times after a data frame in IEEE 802.11 standards, as generally understood by a PHOSITA and illustrated in FIG. 4 and FIG. 5 of the '919 patent). This would reduce overhead and latency associated with waiting for and processing a trigger frame that, in a single-user context, would serve no multi-user coordination purpose. The PHOSITA would adapt the multi-user procedure of US 2014/0286307 A1 by applying known principles of efficiency and single-user direct responses to create the conditional logic described in claims 10 and 15. The difference lies in selecting the most efficient known method (direct response for single user, triggered response for multiple users) based on the context provided by the NDPA, which would be an obvious engineering choice to reduce overhead.

Therefore, the combination of US 2014/0286307 A1 with the general knowledge of a PHOSITA concerning efficient wireless protocols and the desire to minimize overhead for single-user communications would render claims 10 and 15 obvious.

Obviousness of Independent Claim 1 (Scrambling for CTS Frames)

Independent claim 1 describes a method where a wireless device receives an MU-RTS frame with first scrambled data, descrambles it using a first scrambling sequence, and then generates and transmits a CTS frame with second scrambled data using a second scrambling sequence. The crucial element is that the second scrambling sequence is generated based on the first scrambling sequence, specifically by using the "foremost 7 bits" of the first scrambled data (prior to descrambling) as the initial state for the second scrambling sequence. This effectively makes the second sequence a cyclically shifted version of the first.

Lack of Direct Prior Art Combination:

The "Prior Art" section explicitly states that "none of the cited references appear to directly address the specific method of deriving a second scrambling sequence for a CTS frame as a cyclic shift of the first scrambling sequence from a received MU-RTS frame." The cited prior art focuses on MU uplink access and CSI feedback, not the specific intricacies of scrambling sequences for RTS/CTS exchanges in an MU context, particularly for RF-combining.

Rationale for Potential Non-Obviousness (based on provided prior art):

Based solely on the prior art references provided and their descriptions, there is no clear combination that would render independent claim 1 obvious. The unique aspect of RF-combining multiple CTS frames from different stations requires that "all of the two or more transmissions must use a same scrambling sequence." The method of deriving the exact same scrambling sequence (or a precisely related one, like a cyclic shift) among multiple independent responding stations based on a parameter from the initiating frame (MU-RTS) is a specific technical solution to enable successful RF combining, which is not clearly taught or suggested by the cited prior art.

While a PHOSITA would understand basic scrambling (as illustrated in FIGS. 14 and 15 of the '919 patent) and the general concept of using a common sequence for RF combining, the specific mechanism of mandating stations to use the foremost 7 bits of the scrambled bit stream of the received MU-RTS frame (which corresponds to the Scrambler Initialization value in the Service Field of an RXVECTOR) as the initial state for their CTS scrambling sequence appears novel in the context of the provided prior art. This specific technical detail ensures inter-operability and successful RF combining in a multi-user response scenario. Without prior art teaching or explicitly suggesting this particular method of deriving a common and synchronized scrambling sequence among multiple stations for RF-combined responses, it cannot be deemed obvious from the given references.

Therefore, without further prior art disclosing this specific scrambling sequence derivation and synchronization for RF-combined multi-user responses, Independent Claim 1 would likely be considered non-obvious.