Prior art

I will now identify the most relevant prior art for US patent 11272535 based on the provided text.

US Patent 11272535, titled "Method and apparatus for LBT failure detection", describes a User Equipment (UE) that detects Listen-Before-Talk (LBT) failures. The core invention involves a MAC entity of the UE receiving an LBT failure indication from a lower layer for all Uplink (UL) transmissions, increasing an LBT failure counter, determining an LBT failure event if the counter meets a threshold, and resetting the counter under specific conditions (e.g., after a time period without indications, upon MAC entity reset, or reconfiguration of LBT parameters).

Here's an analysis of the cited prior art from the patent text, focusing on their potential anticipation of claims under 35 U.S.C. § 102. The claims of US 11272535 generally revolve around the LBT failure detection mechanism, including the use of a counter, a threshold, and various reset conditions, particularly within the context of UL transmissions in unlicensed spectrum.

Most Relevant Prior Art for US11272535

Based on the provided patent text, the following citations appear to be highly relevant:

1. US20200154480A1: Method And Apparatus For Detecting Consistent Listen Before Talk Failure In Mobile Communications

   • Full Citation: US20200154480A1 (Mediatek Singapore Pte. Ltd.)
   • Publication/Filing Date: Priority date: November 13, 2018. Publication date: May 14, 2020.
   • Brief Description: This patent application describes methods and apparatus for detecting consistent LBT failure in mobile communications. It focuses on a UE performing LBT procedures and determining if a consistent LBT failure occurs. The description highlights the use of an LBT failure counter that increments upon LBT failure and a threshold to determine a consistent failure. It also mentions resetting the counter.
   • Potential Anticipated Claim(s): This reference appears highly relevant to Claims 1 and 10 of US11272535. Specifically, the concepts of:
     • "receiving, by a Medium Access Control (MAC) entity of the UE, a Listen-Before-Talk (LBT) failure indication from a lower layer of the UE for all uplink (UL) transmissions"
     • "increasing an LBT failure counter when the MAC entity receives the LBT failure indication"
     • "determining that an LBT failure event has occurred when the LBT failure counter is greater than or equal to a threshold"
     • "resetting the LBT failure counter"
       are directly discussed or strongly implied. The explicit mention of "consistent LBT failure" and its detection mechanism using a counter and threshold strongly suggests anticipation of the core methodology.

2. US20200221309A1: Handling of channel access problems

   • Full Citation: US20200221309A1 (Qualcomm Incorporated)
   • Publication/Filing Date: Priority date: January 7, 2019. Publication date: July 9, 2020.
   • Brief Description: This patent application addresses handling of channel access problems, which would inherently include LBT failures in unlicensed spectrum. While less specific about the counter mechanism than US20200154480A1, it provides context for detecting and reacting to issues in accessing shared channels.
   • Potential Anticipated Claim(s): Depending on the details within its full text, this could potentially anticipate elements of Claims 1 and 10, particularly regarding the broader concept of detecting and handling "LBT failure events" or "channel access problems" at the MAC layer. Without more detailed information from the cited document itself, it's difficult to pinpoint specific claim elements beyond the general problem statement.

3. US20180184362A1: Licensed assisted access radio link failure

   • Full Citation: US20180184362A1 (Alireza Babaei)
   • Publication/Filing Date: Priority date: December 23, 2016. Publication date: June 28, 2018.
   • Brief Description: This reference discusses Licensed Assisted Access (LAA) and radio link failure (RLF). LBT is a critical component of LAA operations. Therefore, LBT failures could contribute to RLF. The patent may disclose mechanisms for detecting issues leading to RLF in LAA, which could indirectly relate to LBT failure detection.
   • Potential Anticipated Claim(s): This could potentially anticipate aspects of Claims 4 and 13 (performing an RLF recovery procedure) and Claims 5 and 14 (performing a re-establishment procedure due to LBT failure) by establishing the concept of LBT-related issues leading to RLF and subsequent recovery procedures. The specific "LBT failure event" determination with a counter might not be directly anticipated, but the consequence of such an event (RLF) is relevant.

4. US20170231005A1: Channel access counter in a wireless network

   • Full Citation: US20170231005A1 (Ofinno Technologies, Llc)
   • Publication/Filing Date: Priority date: February 4, 2016. Publication date: August 10, 2017.
   • Brief Description: This patent describes a channel access counter in a wireless network. While not explicitly stated as an "LBT failure counter," a channel access counter could conceptually function similarly in an unlicensed spectrum context where LBT is required for channel access.
   • Potential Anticipated Claim(s): This could potentially anticipate the broad concept of using a "counter" related to channel access, as described in Claims 1 and 10 ("increasing an LBT failure counter"). The specific linkage to LBT failure indications from a lower layer for all UL transmissions and the reset conditions would need to be thoroughly examined to determine full anticipation.

5. US20180124825A1: Method and apparatus for performing contention based random access procedure over contention free random access procedure in wireless communication system

   • Full Citation: US20180124825A1 (Lg Electronics Inc.)
   • Publication/Filing Date: Priority date: April 10, 2015. Publication date: May 3, 2018.
   • Brief Description: This patent deals with random access procedures, specifically contention-based random access. In unlicensed spectrum, LBT is a prerequisite for contention-based access. Thus, LBT failures would directly impact these procedures. The patent may describe mechanisms for handling failures within random access, which could indirectly touch upon LBT failure detection or its consequences.
   • Potential Anticipated Claim(s): This might be relevant to Claims 1 and 10 if it discusses feedback about channel access attempts that fail, which could be interpreted as an "LBT failure indication." It may also be relevant to the general context of UL transmissions where LBT is required.

It's important to note that a definitive assessment of anticipation would require a full and detailed claim-by-claim comparison with the complete text and drawings of each cited prior art document. The above analysis is based on the descriptions provided within US11272535's own documentation of its cited prior art.