NR-U Frame-Based Equipment Channel Sensing for COT Sharing

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Solution Overview

Problem

Existing channel access procedures for frame based equipment (FBE) in NR-U do not adequately address transmission priority, collisions, and sharing in Channel Occupancy Time (COT), particularly in scenarios involving multiple unplanned base station deployments and UE-initiated COTs for random access channels, leading to inefficiencies and collisions.

Innovation Solution

Implement two-stage channel sensing with adjustable energy thresholds and continuous/non-continuous second stage sensing to avoid collisions, enhance COT utilization, and introduce procedures for COT sharing and priority-based channel access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional single-stage channel sensing is used for FBE in NR-U, then the channel access procedure is simple, but transmission priority and collision handling are inadequate

Engineering Contradiction:

Improvetransmission priority handlingVSAvoidchannel sensing procedure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The channel sensing procedure is divided into two distinct stages: first stage sensing immediately before the FFP start time, and second stage sensing at configured times during the FFP. This segmentation allows different sensing stages to serve different purposes - the first stage ensures basic channel availability while the second stage handles priority-based collision avoidance, thereby improving transmission priority handling without making the entire procedure overly complex

Inventive Principle:

Principle #1Segmentation

2Reliability

If continuous second stage channel sensing is performed, then collision avoidance is improved, but COT utilization efficiency decreases

Engineering Contradiction:

Improvecollision avoidanceVSAvoidCOT utilization efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The second stage channel sensing is made dynamic by allowing configured times to be adjusted based on transmission priority. High priority transmissions can perform sensing at earlier times, while lower priority transmissions wait. This dynamic adjustment enables collision avoidance for critical transmissions without requiring all transmissions to continuously sense, thereby maintaining COT utilization efficiency

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Different sensing strategies are applied to different transmission priorities locally within the same FFP. High priority transmissions benefit from more aggressive sensing (earlier second stage sensing) while lower priority transmissions use less resource-intensive sensing timing. This local differentiation achieves collision avoidance where needed without unnecessarily reducing COT utilization across all transmissions

Inventive Principle:

Principle #3Local quality

3Reliability

If energy threshold is fixed, then implementation is simple, but priority-based channel access is difficult to achieve

Engineering Contradiction:

Improvepriority-based channel accessVSAvoidenergy threshold configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The energy detection threshold is made dynamic by associating different threshold values with different transmission priorities. High priority transmissions use lower thresholds (more aggressive access) while lower priority transmissions use higher thresholds. This dynamic threshold adjustment enables priority-based channel access by simply configuring threshold values corresponding to priority levels, avoiding complex priority arbitration mechanisms

Inventive Principle:

Principle #15Dynamics

4Productivity

If FBE performs channel sensing only at FFP start time, then device complexity is low, but COT sharing and remaining portion utilization are limited

Engineering Contradiction:

ImproveCOT sharing capabilityVSAvoidchannel sensing timing

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Channel sensing is segmented into multiple timing opportunities: first stage at FFP start time and second stage at configured times during the FFP. This segmentation enables FBE to share COT with other FBE by performing sensing at multiple points, allowing medium priority FBE to access the channel during the remaining portion of the COT without requiring complex continuous sensing throughout the entire FFP

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12543218B2Frame based equipment (FBE) in NR-U

Publication Date: 2026.02.03 INTERDIGITAL PATENT HOLDINGS INC

AI summary

Methods and apparatuses are described herein for transmission priority, collisions, and sharing in the COT by frame based equipment (FBE). In accordance with one embodiment, a wireless communications device such as an FBE, may conduct two stage channel sensing to avoid collision between other FBEs nodes. The wireless communications device may adjust the energy threshold to reflect a channel access priority. The FBE may conducting continuous and non-continuous second stage channel sensing. The FBE may perform enhanced two stage channel sensing to exploit the remaining portion of the COT. The FBE may store a configuration for the second stage of channel sensing for both the downlink (DL) and uplink (UL).