US 11368911

US patent 11368911, titled "Method of physical downlink control channel monitoring and related device," was issued on June 21, 2022, from an application filed on April 27, 2020. The inventors are Hsin-Hsi Tsai, Chia-Hung Wei, and Chie-Ming Chou. The current assignee is Hannibal IP LLC.

Abstract:
The patent describes a method for a User Equipment (UE) to monitor a Physical Downlink Control Channel (PDCCH). The method involves receiving two configurations from a base station: a first search space for monitoring scheduling signals (indicating scheduling information) and a second search space for monitoring a power saving signal (indicating wake-up information associated with Discontinuous Reception, DRX). The UE monitors the first search space when it is in a DRX active time, during which it monitors the PDCCH. Critically, the UE does not monitor the second search space when it is in the DRX active time, thereby saving power. Additionally, if the UE does not receive the power saving signal while monitoring the second search space, it starts a DRX on-duration timer.

Independent Claims Overview:

• Claim 1 (Method Claim):
  This claim outlines a method for a user equipment (UE) to monitor a Physical Downlink Control Channel (PDCCH) to save power. The method includes the following steps:

  1. The UE receives a "first configuration" from a base station, which tells it where to look (a "first search space") on the PDCCH for signals that indicate when data is scheduled to be sent or received.
  2. The UE also receives a "second configuration" from the base station, which tells it where to look (a "second search space") on the PDCCH for a "power saving signal" (like a Wake-Up Signal). This signal contains information about waking up in relation to the UE's Discontinuous Reception (DRX) power-saving mode.
  3. If the UE is monitoring this "second search space" and does not detect the power saving signal, it then starts a DRX "on-duration timer."
  4. When the UE is in its "DRX active time" (a period when it's supposed to be actively monitoring the PDCCH), it monitors the "first search space" for scheduling signals.
  5. However, and this is a key power-saving aspect, when the UE is in its "DRX active time," it does not monitor the "second search space" for the power saving signal.

• Claim 10 (User Equipment Apparatus Claim):
  This claim describes a User Equipment (UE) device itself, designed to perform the method detailed in Claim 1. The UE includes:

  1. A processor, which is the "brain" of the device, executing instructions.
  2. A non-transitory machine-readable medium (like memory), connected to the processor, which stores these instructions.
     The instructions stored on this medium direct the processor to carry out the exact same steps as described in Claim 1:
  • Receive the first configuration for the first search space (for scheduling signals).
  • Receive the second configuration for the second search space (for power saving signals and wake-up information for DRX).
  • In response to not receiving the power saving signal while monitoring the second search space, start a DRX on-duration timer.
  • Monitor the first search space when the UE is in DRX active time.
  • Not monitor the second search space when the UE is in DRX active time.

USPTO and CAFC 2026 Dockets Search Results:
The Google Patents entry for US11368911B2 indicates the patent is "Active, expires 2040-08-11" and lists litigation:

• A PTAB case IPR2025-01189 was filed (Settlement).
• A US case was filed in Texas Eastern District Court (case/4:25-cv-00200).
• First worldwide family litigation was filed.

The details about the IPR case and the Texas Eastern District Court case, along with the "Active" legal status, are directly from the provided patent information, which acts as the authoritative source for this query.## Summary of US Patent 11368911

Title: Method of physical downlink control channel monitoring and related device
Assignee: Hannibal IP LLC
Inventors: Hsin-Hsi Tsai, Chia-Hung Wei, Chie-Ming Chou
Filing Date: 2020-04-27
Issue Date: 2022-06-21

Abstract:
US Patent 11368911 describes a method for a User Equipment (UE) to monitor a Physical Downlink Control Channel (PDCCH) efficiently. The method involves configuring the UE with two distinct search spaces on the PDCCH: a first search space for monitoring scheduling signals (which contain scheduling information), and a second search space for monitoring a power-saving signal (which indicates wake-up information related to Discontinuous Reception, DRX). A core aspect of the invention is that when the UE is in its DRX active time (a period during which it normally monitors the PDCCH), it will monitor the first search space but not the second search space. This prevents redundant monitoring and conserves UE power. Furthermore, if the UE monitors the second search space and does not receive the power saving signal, it initiates a DRX on-duration timer.

Plain-Language Overview of Independent Claims:

• Claim 1 (Method for a User Equipment):
  This claim details a power-saving method for a mobile device (User Equipment or UE) when it's communicating wirelessly.

  1. The UE is set up by a base station to look in a specific area (a "first search space") on the control channel (PDCCH) for messages that tell it when to expect data transmissions.
  2. The UE is also set up to look in another specific area (a "second search space") on the PDCCH for a special "power saving signal" (like a wake-up signal). This signal tells the UE if it needs to become fully active from a power-saving mode called Discontinuous Reception (DRX).
  3. If the UE is checking the "second search space" and doesn't receive this power saving signal, it will then start a timer called the "DRX on-duration timer," preparing to become active.
  4. When the UE is in its "DRX active time" (meaning it's already supposed to be awake and actively listening to the PDCCH), it prioritizes monitoring the "first search space" for data scheduling information.
  5. Crucially, during this "DRX active time," the UE stops monitoring the "second search space" for the power saving signal. This avoids unnecessary power consumption, as the UE is already active.

• Claim 10 (User Equipment Apparatus):
  This claim describes a mobile device (User Equipment or UE) that is designed to perform the power-saving method outlined in Claim 1. The UE consists of:

  1. A processor (the device's central computing unit) that runs instructions.
  2. A non-transitory machine-readable medium (like memory) connected to the processor, which stores these instructions.
     The instructions stored on this medium direct the processor to:
  • Receive configurations for the "first search space" (for scheduling signals) and the "second search space" (for power saving signals related to DRX wake-up information).
  • Start a DRX on-duration timer if the power saving signal is not received while monitoring the second search space.
  • Monitor the first search space when the UE is in its DRX active time.
  • Refrain from monitoring the second search space when the UE is in its DRX active time, thereby implementing the power-saving mechanism.

Legal Status and Dockets:
US Patent 11368911 is currently active and is set to expire on August 11, 2040.
Public records indicate that this patent family is involved in litigation:

• A PTAB case, IPR2025-01189, has been filed and subsequently settled.
• A US case (4:25-cv-00200) has been filed in the Texas Eastern District Court.
• There has also been a first worldwide family litigation filed.

US11368911B2 - Method of physical downlink control channel monitoring and related device - Google Patents. https://patents.google.com/patent/US11368911B2/en. Accessed April 26, 2026.
IPR2025-01189 - Unified Patents. https://portal.unifiedpatents.com/[ptab](/ptab)/case/IPR2025-01189. Accessed April 26, 2026.
4:25-cv-00200 - Unified Patents. https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/4:25-cv-00200. Accessed April 26, 2026.
Darts-ip. https://patents.darts-ip.com/?family=73017514&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=[US11368911](/patent/US11368911)(B2). Accessed April 26, 2026.

Proceedings overview

There is one AIA trial proceeding on file for US patent 11368911. The proceeding was an Inter Partes Review (IPR) which terminated due to settlement, meaning no claims were formally invalidated or sustained by the Patent Trial and Appeal Board (PTAB). This leaves the patent's claims untested by the PTAB on the merits, offering a different defensive posture than one with adjudicated claims.

IPR2025-01189 — [[[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. Hannibal IP LLC

• Type: Inter Partes Review
• Filed: 2025-07-11
• Status: Terminated-Settled. The proceeding concluded without a final written decision on the merits due to a settlement between the parties.
• Judge panel: Information regarding the specific Administrative Patent Judges (APJ) panel for this proceeding is not publicly available in the provided sources at this time.
• Petition grounds: The petition was filed by Samsung Electronics Co., Ltd. et al. against patent 11368911. Specific details of the challenged claims, prior art, and statutory bases (§ 102 / § 103 / § 112) of the petition are not available in the provided context or readily discoverable through general public searches for a settled IPR without a published institution decision or final written decision.
• Institution decision: Details regarding whether the IPR was instituted, denied, or partially instituted are not publicly available due to the settlement.
• Final Written Decision: Not issued, as the proceeding terminated due to settlement.
• Settlement / termination: The proceeding was last modified on 2026-04-17 with a status of "Terminated-Settled". The specific terms of the settlement are confidential between Samsung Electronics Co., Ltd. et al. and Hannibal IP LLC.
• Appeal: No appeal to the Federal Circuit occurred, as there was no Final Written Decision to appeal.
• Defensive value: Since this IPR was settled, no claims of US11368911 were invalidated by the PTAB. For a defendant facing assertion of this patent, this means the claims have not been challenged and found unpatentable in an IPR setting. However, the settlement itself could indicate a strategic decision by the patent owner or petitioner, which may or may not reflect on the underlying patentability of the claims. The claims remain untested in this specific IPR.

Strategic summary

All claims of US11368911 remain UNTESTED by the PTAB on the merits. The single IPR filed, IPR2025-01189, terminated due to a settlement, meaning the PTAB did not issue a decision on the patentability of any claims. Therefore, the patent has not been narrowed through IPR.

Regarding the estoppel landscape, § 315(e)(2) bars the petitioner (Samsung Electronics Co., Ltd. et al.) and their privies from raising any ground they raised or reasonably could have raised during IPR2025-01189. For other defendants being asserted against, this specific IPR does not create estoppel against them, and the prior-art grounds that could have been used against this patent remain available for new challenges.

The involvement of Samsung Electronics Co., Ltd. as a petitioner suggests that the patent's technology is relevant to major players in the wireless communication space. The "Terminated-Settled" status for IPR2025-01189 is a common outcome in PTAB proceedings and often occurs when the parties reach a broader licensing agreement or resolution that encompasses the patent.

Recommended next steps

Given that the only PTAB proceeding on US11368911 concluded in a settlement without a Final Written Decision, there are no claims that have been invalidated or confirmed as patentable by the PTAB.
If you are a defendant facing assertion of this patent, the patent claims remain as originally granted.
There are no active proceedings or upcoming trial-stage milestones for this patent at the PTAB.

Inventors

• Hsin-Hsi Tsai: Likely employed by FG Innovation Company Limited at the time of invention/filing, as rights were assigned from the inventors to FG Innovation Company Limited on the application filing date.
• Chia-Hung Wei: Likely employed by FG Innovation Company Limited at the time of invention/filing.
• Chie-Ming Chou: Likely employed by FG Innovation Company Limited at the time of invention/filing.

Original assignee

Hannibal IP LLC is listed as the original assignee on the issued patent and was the entity that filed the application.
Hannibal IP LLC does not appear to ship products embodying the claims; its primary line of business is patent acquisition, licensing, and assertion, characteristic of a non-practicing entity due to its "IP LLC" naming convention and litigation activity.
Hannibal IP LLC is currently operating, as the patent is active and involved in ongoing litigation.

Assignment timeline

• 2020-04-27 (executed) / recorded 2020-04-27 — Reel 054174/0936

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: CHOU, CHIE-MING, TSAI, HSIN-HSI, WEI, CHIA-HUNG (the inventors)
  • Assignee: FG INNOVATION COMPANY LIMITED
  • Correspondent: BAKER & MCKENZIE LAW OFFICES, LLP, INTELLECTUAL PROPERTY DEPARTMENT, 275 Battery Street, 26th Floor, San Francisco, CA 94111-3399
  • Context: Transfer of inventive rights from individual inventors to an operating company (FG Innovation Company Limited).

• 2021-09-15 (executed) / recorded 2021-09-15 — Reel 058140/0178

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: FG INNOVATION COMPANY LTD.
  • Assignee: HANNIBAL IP LLC
  • Correspondent: BAKER & MCKENZIE LAW OFFICES, LLP, INTELLECTUAL PROPERTY DEPARTMENT, 275 Battery Street, 26th Floor, San Francisco, CA 94111-3399. This same correspondent (Baker & McKenzie) also handled the previous assignment in this chain.
  • Context: Transfer from an operating company to a patent assertion entity.

Timeline diagram

timeline
    title Ownership of US 11368911
    2020 : Filed by Hannibal IP LLC
         : Inventors assign to FG Innovation
    2021 : Assigned to Hannibal IP LLC
    2022 : Patent issued
    2025 : First infringement suit filed

NPE / troll-pattern signals

1. Shell-entity transfer — present. The patent was transferred from FG Innovation Company Limited (likely an operating company) to Hannibal IP LLC, an entity with "IP LLC" in its name and no apparent products in commerce. The nature of Hannibal IP LLC, as evidenced by its name and assertion activity, points to it being a licensing-only entity.
2. Known asserter in the chain — present. Hannibal IP LLC is the current assignee and has been identified as involved in a PTAB case (IPR2025-01189) and a US District Court case (4:25-cv-00200 in Texas Eastern District Court), indicating a pattern of patent assertion.
3. Repeat correspondent across the chain — present. BAKER & MCKENZIE LAW OFFICES, LLP, INTELLECTUAL PROPERTY DEPARTMENT is listed as the correspondent for both the 2020-04-27 assignment (Reel 054174/0936) and the 2021-09-15 assignment (Reel 058140/0178).
4. Cascading transfers — present. There are two transfers within a relatively short period (less than two years from the initial inventor assignment to the assignment to Hannibal IP LLC), and both assignments share the same correspondent. The inventors assigned to FG Innovation on 2020-04-27, and FG Innovation assigned to Hannibal IP LLC on 2021-09-15.
5. Pre-litigation transfer — not present. The assignment to Hannibal IP LLC was executed and recorded on 2021-09-15. The first recorded litigation in the Texas Eastern District Court (4:25-cv-00200) was filed in 2025, which is more than six months after the assignment.
6. Bankruptcy fire-sale — not present. There is no indication in the patent record or associated legal events that the patent was sold as part of a bankruptcy proceeding.
7. Privateering — unclear. While FG Innovation Company Limited (the assignor to Hannibal IP LLC) appears to be an operating company, it is not clear from the available data whether Hannibal IP LLC is asserting the patent on FG Innovation's behalf against specific competitors.
8. Defensive aggregator (anti-NPE) — not present. The patent is currently held by Hannibal IP LLC, an asserting entity, not a defensive aggregator.

Verdict

NPE — high confidence
This verdict is based on multiple strong signals, including the clear shell-entity transfer from an apparent operating company (FG Innovation Company Limited) to Hannibal IP LLC (Reel 058140/0178, 2021-09-15), the involvement of Hannibal IP LLC in multiple patent assertion litigations, and the recurrence of the same correspondent (Baker & McKenzie Law Offices, LLP) across both recorded assignments.

USPTO Assignment Center Search for US11368911

To identify the most relevant prior art for US patent 11368911, I will examine the "Cited By" and "Citations" sections from the Google Patents entry, which typically list both forward and backward citations. For each patent cited in the "Citations" section (prior art to US11368911), I will provide the requested details.

USPTO Database Search for Patent 11368911:

The USPTO provides a Patent Public Search tool. Through this tool, one can search for patents by number. Searching specifically for patent number 11368911 on the USPTO Patent Public Search will confirm its details and provide access to its full record.

Most Relevant Prior Art for US Patent 11368911:

The following are the patent citations listed in US11368911, which represent prior art considered during its examination:

1. US20180124701A1

   • Full Citation: US20180124701A1, Mediatek Inc., "Scheduling request (sr) period extension for low power enhancement in a wireless communication device", Publication date: 2018-05-03, Priority date: 2016-10-31.
   • Brief Description: This publication describes methods for extending a scheduling request (SR) period to enhance low power consumption in a wireless communication device, which could be relevant to DRX operations and power saving.
   • Potential Anticipation (35 U.S.C. § 102): This reference potentially anticipates aspects of the power-saving objective mentioned in Claim 1 and Claim 10 of US11368911, specifically regarding methods to reduce power consumption in a UE, although the mechanism (SR period extension) is different from WUS and search space monitoring. Anticipation under 35 U.S.C. § 102 occurs if every element of a claim is found, either expressly or inherently described, in a single prior art reference.

2. US20180145800A1

   • Full Citation: US20180145800A1, [[Samsung Electronics Co.](/litigations/by-defendant/Samsung%20Electronics%20Co.), Ltd.](/litigations/by-plaintiff/Samsung%20Electronics%20Co.%2C%20Ltd.), "Method of reducing power consumption in user equipment", Publication date: 2018-05-24, Priority date: 2016-11-24.
   • Brief Description: This patent application details a method for reducing power consumption in a user equipment.
   • Potential Anticipation (35 U.S.C. § 102): Similar to the previous citation, this reference addresses the broad concept of UE power saving, which is the underlying goal of US11368911. It might anticipate the general idea of reducing power consumption in a UE, but the specific mechanisms of using distinct search spaces and conditional monitoring for scheduling and power-saving signals, as defined in Claims 1 and 10, would need a detailed comparison.

3. US20180270756A1

   • Full Citation: US20180270756A1, Qualcomm Incorporated, "Techniques and apparatuses for control channel monitoring using a wakeup signal", Publication date: 2018-09-20, Priority date: 2017-03-17.
   • Brief Description: This publication discloses techniques and apparatuses for control channel monitoring utilizing a wake-up signal (WUS). This directly relates to the WUS mechanism described in US11368911.
   • Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant as it explicitly mentions "wake-up signal" and "control channel monitoring." It could potentially anticipate aspects of Claim 1 and Claim 10 concerning the use of a power-saving signal (WUS) and its association with a DRX functionality for wake-up information. The novelty of US11368911 may lie in the specific conditional non-monitoring of the WUS search space during DRX active time and the starting of the DRX on-duration timer based on not receiving the WUS.

4. US20180332533A1

   • Full Citation: US20180332533A1, Qualcomm Incorporated, "Wake-up signal (wus) and wake-up receiver (wur) in a communication device", Publication date: 2018-11-15, Priority date: 2017-05-15.
   • Brief Description: This publication describes a wake-up signal (WUS) and a wake-up receiver (WUR) in a communication device.
   • Potential Anticipation (35 U.S.C. § 102): Similar to US20180270756A1, this reference's focus on WUS and WUR directly relates to the power-saving signal concept in US11368911. It may anticipate the general use of a WUS for power saving. However, the distinct configurations of two search spaces and the specific monitoring/non-monitoring behavior during DRX active time, as claimed in US11368911, would need careful comparison to determine full anticipation.

5. US20190190582A1

   • Full Citation: US20190190582A1, Samsung Electronics Co., Ltd., "Method and apparatus for beam reporting in next generation wireless systems", Publication date: 2019-06-20, Priority date: 2017-12-19.
   • Brief Description: This patent application describes methods and apparatus for beam reporting in next-generation wireless systems. While related to wireless communication, its primary focus is beam management rather than specific PDCCH monitoring for power saving using WUS.
   • Potential Anticipation (35 U.S.C. § 102): This reference is less directly related to the core innovation of US11368911. It is unlikely to anticipate Claims 1 or 10, as its subject matter (beam reporting) does not appear to cover the specific aspects of power-saving PDCCH monitoring using distinct search spaces and conditional monitoring behavior.

6. US20190254110A1

   • Full Citation: US20190254110A1, Samsung Electronics Co., Ltd., "Method and apparatus for power savings at a user equipment", Publication date: 2019-08-15, Priority date: 2018-02-14.
   • Brief Description: This publication outlines a method and apparatus for power savings at a user equipment.
   • Potential Anticipation (35 U.S.C. § 102): This reference broadly covers power-saving methods for UEs. It potentially anticipates the overarching goal of power saving in Claims 1 and 10. The extent of anticipation would depend on whether its disclosed power-saving techniques involve the specific combination of search space configurations, WUS monitoring, and conditional non-monitoring during DRX active time as claimed in US11368911.

7. US20190297577A1

   • Full Citation: US20190297577A1, Samsung Electronics Co., Ltd., "Method and apparatus for power saving signal design in nr", Publication date: 2019-09-26, Priority date: 2018-03-23.
   • Brief Description: This publication focuses on the design of power-saving signals in New Radio (NR) systems.
   • Potential Anticipation (35 U.S.C. § 102): This is another highly relevant reference as it discusses "power saving signal design in NR," which directly relates to the "power saving signal" (WUS) in US11368911. It could potentially anticipate aspects of the second configuration and the use of a power-saving signal as described in Claims 1 and 10. A detailed comparison would be needed to see if the specific monitoring behaviors and interactions with DRX active time, as claimed in US11368911, are also explicitly or inherently present.

8. US20200037396A1

   • Full Citation: US20200037396A1, Toufiqul Islam, "Downlink control channel signaling for improving ue power consumption", Publication date: 2020-01-30, Priority date: 2018-07-24.
   • Brief Description: This publication describes downlink control channel signaling aimed at improving UE power consumption.
   • Potential Anticipation (35 U.S.C. § 102): This reference addresses improving UE power consumption through downlink control channel signaling, which aligns with the general problem US11368911 seeks to solve. It might anticipate aspects of the power-saving methodology, but the specific configuration of two distinct search spaces and the conditional monitoring logic for WUS during DRX active time would need to be compared to determine anticipation of Claims 1 and 10.

9. US20200092814A1

   • Full Citation: US20200092814A1, Hua Zhou, "Power Saving in a Wireless Communication System", Publication date: 2020-03-19, Priority date: 2018-09-19.
   • Brief Description: This publication focuses on power saving in a wireless communication system.
   • Potential Anticipation (35 U.S.C. § 102): This broadly covers power-saving techniques in wireless communication. Like other general power-saving references, it could anticipate the overall goal, but the specific implementation details of US11368911, particularly the dual search space configuration and the conditional non-monitoring of the power-saving signal during DRX active time, would likely remain novel unless explicitly detailed in this reference.

10. US20200229092A1

    • Full Citation: US20200229092A1, Samsung Electronics Co., Ltd., "Method and apparatus for monitoring physical downlink control channel", Publication date: 2020-07-16, Priority date: 2019-01-10.
    • Brief Description: This publication describes a method and apparatus for monitoring a physical downlink control channel.
    • Potential Anticipation (35 U.S.C. § 102): This reference is very relevant as it deals with "monitoring physical downlink control channel," which is the core subject of US11368911. It is likely to anticipate aspects of how PDCCH monitoring is performed. The key for US11368911's novelty would be the specific two-search-space approach, the power-saving signal, and the conditional non-monitoring during DRX active time, which would need to be thoroughly compared against this reference.

11. US20210022202A1

    • Full Citation: US20210022202A1, Samsung Electronics Co., Ltd., "Method and apparatus for performing discontinuous reception in wireless communication system", Publication date: 2021-01-21, Priority date: 2018-03-29.
    • Brief Description: This publication describes methods and apparatus for performing discontinuous reception (DRX) in a wireless communication system.
    • Potential Anticipation (35 U.S.C. § 102): This reference is highly relevant due to its focus on "discontinuous reception (DRX)." Since US11368911's claims are explicitly tied to DRX functionality and DRX active time, this prior art could potentially anticipate various elements related to DRX operation. The specific novelty of US11368911 would rest on the combination of a power-saving signal, distinct search spaces, and the precise rule of not monitoring the power-saving signal search space during DRX active time, and how this differs from or builds upon the DRX methods in this reference.

Obviousness Analysis of US Patent 11368911 under 35 U.S.C. § 103

This analysis evaluates the obviousness of US patent 11368911, specifically claims 1 (method) and 10 (apparatus), by combining teachings from relevant prior art references. The Person Having Ordinary Skill in the Art (PHOSITA) is presumed to be an engineer or researcher knowledgeable in 3GPP wireless communication standards, particularly concerning power saving mechanisms in New Radio (NR) and Long Term Evolution (LTE) systems, including Discontinuous Reception (DRX) and Physical Downlink Control Channel (PDCCH) monitoring.

Independent Claims Overview (Recap)

• Claim 1 (Method): This claim describes a method for a User Equipment (UE) to monitor a PDCCH by:
  1. Receiving a first configuration for a first search space to monitor scheduling signals.
  2. Receiving a second configuration for a second search space to monitor a power saving signal (WUS) indicating wake-up information for DRX.
  3. Starting a DRX on-duration timer if the power saving signal is not received while monitoring the second search space.
  4. Monitoring the first search space when the UE is in DRX active time.
  5. Critically, not monitoring the second search space when the UE is in DRX active time.
• Claim 10 (Apparatus): This claim covers a UE comprising a processor and memory configured to perform the method steps of Claim 1.

Prior Art Background

Prior to the filing date of US11368911 (April 27, 2020), the concepts of DRX for UE power saving and Wake-Up Signals (WUS) were well-established and actively discussed within 3GPP for 5G NR.

1. Discontinuous Reception (DRX): DRX is a fundamental power-saving mechanism in RRC_CONNECTED mode, allowing a UE to periodically wake up during "on-duration" periods to monitor the PDCCH for scheduling grants and then return to a sleep state. This mechanism significantly reduces power consumption compared to continuous monitoring. The DRX active time, including the on-duration and periods influenced by timers like drx-InactivityTimer, designates when the UE is actively monitoring the PDCCH for scheduling signals.
2. Wake-Up Signals (WUS): The WUS was introduced in 3GPP Release 16 (and earlier in LTE for LPWA devices) as an enhancement to DRX, aiming to further reduce unnecessary PDCCH monitoring. A WUS is typically sent by the network before a scheduled DRX on-duration. If the UE successfully receives the WUS, it proceeds to monitor the PDCCH during the upcoming on-duration. If the WUS is not received, the UE can infer that no data is pending and can skip the entire on-duration period, remaining in a deeper sleep state to save power.
3. Dedicated Search Spaces: Both standard PDCCH monitoring for scheduling and WUS monitoring are performed within configured search spaces or Control Resource Sets (CORESETs). US20180332533A1, for instance, explicitly discusses a UE periodically awakening to monitor for a WUS in a "wake-up signal search space."

Obviousness Argument

The claimed invention in US11368911 primarily differentiates itself by two specific behaviors: (1) not monitoring the WUS search space when the UE is already in DRX active time, and (2) starting a DRX on-duration timer if the WUS is not received while monitoring the second search space.

Combination of Prior Art References

A persuasive combination of prior art that would render Claims 1 and 10 obvious includes:

1. US20180332533A1 (Qualcomm): This patent application, with a priority date of May 15, 2017, explicitly teaches a UE periodically awakening to monitor for a Wake-Up Signal (WUS) in a "wake-up signal search space." The WUS is designed to inform the UE whether it should monitor for a control channel communication. This reference clearly establishes the concept of a dedicated search space for a power-saving (wake-up) signal.
2. General knowledge of DRX operation in NR/LTE (e.g., Huawei BLOG, Ericsson, EE World Online): These and numerous other sources detail the conventional DRX mechanism, including the "DRX active time" during which the UE monitors the PDCCH for scheduling grants. This active time typically involves the drx-onDurationTimer and drx-InactivityTimer being active, during which the UE is fully powered up for PDCCH monitoring.

Motivation for Combination

The motivation for a PHOSITA to combine the teachings of a dedicated WUS search space with conventional DRX operation to arrive at the claimed invention is rooted in the widely recognized problem of unnecessary power consumption due to redundant monitoring and the inherent design goal of WUS: to save power.

The '911 patent's own background section (and related art references) highlights the issue: "the running drx-InactivityTimer may keep the UE awake even without PDCCH scheduling, or whether or not there is PDCCH scheduling, the drx-onDurationTimer may still periodically trigger the UE to wake up. This situation may be called PDCCH-only monitoring... which causes unnecessary power consumption in RRC connected mode." Furthermore, the patent acknowledges the scenario where "the time domain of the CORESET (or search space) for the WUS may collide with the CORESET (or search space) for scheduling by the PDCCH, as shown in FIG. 3." This collision during DRX active time would lead to the UE simultaneously monitoring both search spaces, which is explicitly identified as increasing power consumption.

The overarching motivation for implementing WUS in 5G NR is to reduce UE power consumption by allowing the UE to skip PDCCH monitoring when no data is expected.

• "Not monitoring the second search space in response to the UE being in the DRX active time":
  A PHOSITA, observing the known collision scenarios (as illustrated in prior art diagrams like FIG. 3 and FIG. 4 of the '911 patent itself, described as "related art methods") and understanding the fundamental purpose of WUS, would be logically motivated to prevent redundant monitoring. If the UE is already in "DRX active time" (i.e., actively monitoring the PDCCH for scheduling signals), its primary receiver is already awake and consuming power. In this state, monitoring a wake-up signal becomes redundant and unnecessary, as the UE is already "awake." The '911 patent itself explicitly articulates this motivation: "if the UE is already in the DRX active time, it is unnecessary to monitor the WUS. Thus, the UE may not need to monitor the WUS when the UE is in DRX active time, so as to reduce the power consumption." This statement from the patent's detailed description serves as direct evidence of the obvious motivation to a PHOSITA. Eliminating such redundant monitoring directly contributes to the well-known goal of saving UE power.

• "In response to not receiving the power saving signal while monitoring the second search space, starting a DRX on-duration timer":
  The prior art (e.g., Nokia, Huawei BLOG, arXiv) teaches that if the WUS is not received, the UE can skip the on-duration. This implies a decision point. Conversely, if the network has configured the WUS as an advisory signal, or if a robust fallback mechanism is desired such that the UE still enters its scheduled on-duration despite not detecting the WUS (e.g., due to poor WUS reception or to maintain a baseline DRX activity), then starting the drx-onDurationTimer would be a straightforward and logical design choice within the established DRX framework. The patent's own description indicates this as a possible behavior: "the UE may start or restart the drx-onDurationTimer (on a DRX cycle) when the UE does not monitor and/or receive the WUS on the WUS occasion (before the DRX cycle), or when the UE is in the DRX active time." This demonstrates that such timer management in response to WUS non-reception was a contemplated and obvious design choice for managing DRX states.

Conclusion

Given the pervasive desire to optimize UE power consumption in wireless communication, and the well-known mechanisms of DRX and WUS for achieving this, a PHOSITA would have been motivated to combine the concept of dedicated WUS search spaces (as in US20180332533A1) with the established DRX framework (as in Huawei BLOG, Ericsson, EE World Online). The explicit motivation, even stated within the US11368911 patent itself, to avoid redundant WUS monitoring when the UE is already in an active DRX state, would lead a PHOSITA to the "not monitoring the second search space" limitation. Similarly, managing the drx-onDurationTimer based on WUS reception or non-reception represents a logical design choice or fallback mechanism within the known DRX operation to balance power saving with network reachability.

Therefore, the methods of Claim 1 and the apparatus of Claim 10 of US11368911 would have been obvious to a PHOSITA at the time of the invention.