COT Sharing in FBE Frames for Low-Latency Channel Access

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Solution Overview

Problem

In wireless communication systems operating in frame-based-equipment (FBE) mode over a shared frequency band, there is a need for efficient channel occupancy time (COT) sharing mechanisms to reduce transmission latency and optimize resource utilization, particularly for ultra-reliable low-latency communications (URLLC) scenarios.

Innovation Solution

User equipment (UE) initiates COT acquisition by performing a listen-before-talk (LBT) procedure during idle periods of FBE frames and shares a portion of the acquired COT with the base station (BS) through COT sharing information, enabling flexible CG-based transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If UE performs LBT procedure to acquire COT in FBE mode, then transmission latency is reduced, but channel access reliability deteriorates due to contention conflicts

Engineering Contradiction:

Improvetransmission latencyVSAvoidchannel access reliability

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The patent introduces COT sharing information as an intermediary mechanism that mediates between UE and BS for channel access. The UE shares its acquired COT with the BS by providing COT sharing information, allowing the BS to perform LBT with a reduced contention window or skip LBT entirely, thus reducing transmission latency while maintaining channel access reliability through coordinated access

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If UE shares COT with BS, then resource utilization is improved, but device complexity increases due to COT sharing information management

Engineering Contradiction:

Improveresource utilizationVSAvoidCOT sharing information management

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the UE determine and provide COT sharing information to the BS in advance, before the BS needs to access the channel. This includes calculating the remaining COT duration and notifying the BS of the sharing arrangement beforehand, which simplifies the overall system coordination and reduces the complexity of real-time COT management

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If BS uses fixed COT duration in FBE mode, then system simplicity is maintained, but adaptability to different traffic scenarios deteriorates

Engineering Contradiction:

Improvesystem simplicityVSAvoidadaptability to traffic scenarios

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by allowing the COT duration to be variable rather than fixed. The BS determines the COT duration based on traffic requirements and UE capabilities, and the COT sharing information dynamically adjusts the effective COT duration for BS transmissions. This enables the system to adapt to different traffic scenarios (e.g., URLLC, eMBB) while maintaining relatively simple FBE frame structure

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12507281B2Channel occupancy time sharing for frame-based equipment

Publication Date: 2025.12.23 QUALCOMM INC

AI summary

Wireless communication systems and methods related to channel occupancy time (COT) sharing when operating in a frame-based-equipment (FBE) mode over a shared frequency band are provided. In one aspect, a user equipment (UE) contends for a channel occupancy time (COT) in a first frame-based equipment (FBE) frame. The UE transmits, to a base station (B S), an uplink communication signal during a first portion of the COT. The UE receives, from the BS based on COT sharing information, a downlink communication signal during a second portion of the COT, wherein the second portion is non-overlapping with the first portion.