Autonomous Uplink Control for LBT Coexistence With Scheduled UEs

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Solution Overview

Problem

LTE uplink transmissions in unlicensed spectrum face performance issues due to centralized coordination and Listen-Before-Talk (LBT) regulations, leading to inferior performance compared to Wi-Fi in congested networks, and unscheduled LTE uplink transmissions degrade scheduled LTE performance by occupying channel gaps.

Innovation Solution

Implementing systems and methods to restrict autonomous uplink transmissions by wireless devices, using indications from a radio access node to manage which subframes belong to a channel occupancy, ensuring coexistence with scheduled uplink transmissions by controlling when autonomous uplink transmissions can occur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If autonomous uplink transmissions are allowed in unlicensed spectrum, then uplink throughput and latency are improved, but interference with scheduled transmissions increases and coexistence with Wi-Fi deteriorates

Engineering Contradiction:

Improveuplink throughputVSAvoidinterference with scheduled transmissions

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The base station performs preliminary actions by sending control signals (e.g., PDCCH/EPDCCH) to schedule uplink transmissions before the actual autonomous uplink transmissions occur. This allows the system to pre-coordinate resource usage and prevent interference by establishing transmission rules in advance, resolving the contradiction between enabling autonomous transmissions and preventing interference with scheduled transmissions

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts transmission parameters and timing based on real-time channel conditions and interference levels. The base station can modify scheduling decisions, power levels, and resource allocation dynamically to balance autonomous uplink performance with protection of scheduled transmissions, allowing the system to adapt to changing conditions and maintain coexistence

Inventive Principle:

Principle #15Dynamics

2Reliability

If Listen-Before-Talk (LBT) scheme is applied in unlicensed spectrum, then coexistence with Wi-Fi is improved, but uplink transmission latency and complexity increase

Engineering Contradiction:

Improvecoexistence with Wi-FiVSAvoiduplink transmission latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The base station performs preliminary LBT and channel assessment actions before scheduling autonomous uplink transmissions. By pre-checking channel availability and coordinating with Wi-Fi networks in advance, the system reduces the need for repeated LBT procedures at the UE level, thereby maintaining coexistence with Wi-Fi while reducing overall transmission latency

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements self-service mechanisms where UEs autonomously perform LBT procedures based on pre-configured parameters and rules provided by the base station. This distributes the LBT burden from the network to individual devices, reducing network complexity and allowing parallel LBT operations that decrease overall latency while maintaining reliable coexistence

Inventive Principle:

Principle #25Self-service

3Reliability

If centralized coordination is used for LTE uplink in unlicensed spectrum, then transmission reliability is improved, but device autonomy and response time are reduced

Engineering Contradiction:

Improvetransmission reliabilityVSAvoiddevice autonomy

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system segments coordination functions by dividing responsibilities between the base station (centralized coordination for scheduling and resource allocation) and individual UEs (autonomous execution of transmissions and local LBT procedures). This segmentation allows UEs to operate autonomously within defined parameters while maintaining overall network coordination, thus preserving both reliability and device autonomy

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The base station performs preliminary coordination actions by providing UEs with pre-configured transmission parameters, resource allocations, and LBT rules before autonomous transmissions begin. This preliminary centralized coordination establishes reliable operational frameworks that enable subsequent autonomous device operations without requiring continuous centralized control, balancing reliability with device autonomy

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS12477580B2Controlling AUL transmissions when coexisting with scheduled UEs

Publication Date: 2025.11.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Systems and methods are disclosed herein for restricting autonomous uplink transmissions by a wireless device in a wireless communication system such that wireless devices performing autonomous uplink transmissions can coexist with wireless devices performing scheduled uplink transmissions in a cell requiring Listen-Before-Talk (LBT). In some embodiments, a method of operation of a wireless device in a wireless communication system comprises receiving, from a radio access node, an indication of which subframes belong to a same channel occupancy within a cell that requires LBT and restricting performance of autonomous uplink transmissions by the wireless device based on the indication of which subframes belong to the same channel occupancy. By restricting autonomous uplink transmissions in this manner, the wireless device can coexist with scheduled wireless devices in the same cell.