Restricting UE Autonomous Uplink Transmissions in LTE Unlicensed Spectrum

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Solution Overview

Problem

In LTE networks, autonomous uplink transmissions on unlicensed carriers can lead to unwanted simultaneous transmissions with scheduled uplink signals, causing power control issues and potential confusion in HARQ-process identity, as well as interfering with channel access procedures, especially in carrier aggregation scenarios.

Innovation Solution

Defining additional restrictions on when grantless uplink transmissions are allowed, such as prohibiting them during or after scheduled uplink transmissions, to ensure that autonomous transmissions do not occur at unwanted times and prevent interference with scheduled signals, using configurations like bitmaps for radio resource control signaling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If autonomous uplink transmissions are allowed on unlicensed carriers, then uplink data transmission efficiency is improved, but power control issues and HARQ-process identity confusion occur due to simultaneous transmissions with scheduled uplink signals

Engineering Contradiction:

Improveuplink data transmission efficiencyVSAvoidpower control stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by configuring the UE with a bitmap indicating subframes where autonomous transmissions are prohibited before the actual transmissions occur. This preemptive restriction prevents simultaneous transmissions with scheduled uplink signals, thereby avoiding power control issues and HARQ-process identity confusion while still allowing autonomous transmissions in permitted subframes to maintain uplink data transmission efficiency.

Inventive Principle:

Principle #9Preliminary anti-action

2Productivity

If autonomous uplink transmissions are permitted, then network resource utilization is improved, but channel access procedures are interfered with

Engineering Contradiction:

Improvenetwork resource utilizationVSAvoidchannel access interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the uplink transmission opportunities by dividing subframes into two categories: those where autonomous transmissions are allowed and those where they are prohibited (indicated by the bitmap). This segmentation prevents autonomous transmissions during subframes where scheduled transmissions occur, thereby avoiding interference with channel access procedures while maintaining network resource utilization in permitted subframes.

Inventive Principle:

Principle #1Segmentation

3Device complexity

If grantless uplink transmissions are allowed without restrictions, then implementation complexity is reduced, but simultaneous transmissions cause confusion in HARQ-process identity

Engineering Contradiction:

Improvetransmission control complexityVSAvoidHARQ-process identity clarity

Core Design Contradiction:

Device complexityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by providing the UE with a pre-configured bitmap that indicates which subframes are prohibited for autonomous transmissions. This preliminary configuration allows the UE to autonomously determine whether to transmit without real-time network intervention, maintaining low implementation complexity. Simultaneously, it prevents HARQ-process identity confusion by ensuring autonomous transmissions do not occur in subframes with scheduled transmissions.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10721757B2Methods and apparatuses for restricting user equipment autonomous transmissions

Publication Date: 2020.07.21 NOKIA TECHNOLOGIES OY

AI summary

Systems, methods, apparatuses, and computer program products for restricting UE autonomous transmissions are provided.