Dynamic Slot Format Indication for Unlicensed Band Energy Reduction

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Solution Overview

Problem

In wireless communications, especially in unlicensed bands, the uncertainty of channel occupancy time due to Listen Before Talk (LBT) mechanisms leads to inefficiencies in resource utilization, as devices struggle to adapt slot format information from licensed bands to unlicensed bands, resulting in increased energy consumption and reduced performance.

Innovation Solution

The method involves a network device sending second indication information to a terminal about the channel occupancy time (COT) format, allowing the terminal to learn the available COT and slot format, enabling flexible time domain start and end positions for communication, thereby reducing blind detection overheads and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If slot format information from licensed bands is used for unlicensed band communication, then communication can be established, but resource utilization efficiency deteriorates due to uncertainty of channel occupancy time

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidadaptability to LBT uncertainty
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent makes the slot format indication dynamic by allowing the network device to flexibly indicate slot formats within the COT based on actual channel conditions and LBT results. The slot format can be adjusted in real-time to match the uncertain channel occupancy duration, transforming the static licensed-band approach into a dynamic unlicensed-band adapted system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of slot format indication timing and content to adapt to unlicensed band characteristics. By modifying when and how slot format information is indicated (through downlink control information in the COT), the system adjusts to the variable channel occupancy time caused by LBT mechanisms.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If terminals continuously monitor for slot format information, then communication reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidterminal energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic monitoring where terminals wake up at specific intervals or triggered events to check for slot format indications from the network device, rather than continuously monitoring. This periodic approach maintains communication reliability by ensuring terminals check for updates at appropriate times while significantly reducing energy consumption during idle periods.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The network device provides slot format indication information proactively through downlink control information, allowing terminals to obtain necessary communication parameters without intensive active monitoring. Terminals can enter low-power states and still receive critical information when transmitted by the network, reducing their own energy expenditure while maintaining reliability.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If blind detection is performed to determine COT format, then communication flexibility is achieved, but detection overhead increases

Engineering Contradiction:
Improvecommunication flexibilityVSAvoiddetection overhead
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The network device performs preliminary action by indicating the COT format and slot formats in advance through downlink control information before the terminal needs to communicate. This eliminates the need for the terminal to perform complex blind detection, as the format information is provided upfront, reducing detection overhead while maintaining flexibility.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces downlink control information as an intermediary that carries slot format indication from the network device to the terminal. This intermediary mechanism transfers the format information efficiently, eliminating the need for the terminal to independently perform blind detection and reducing overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3863203B1Method and apparatus for transmitting indication information
Publication Date: 2024.09.25 HUAWEI TECH CO LTD
  • EP3863203B1 patent drawingFigure 1
  • EP3863203B1 patent drawingFigure 2
  • EP3863203B1 patent drawingFigure 3~4

AI summary

Embodiments of this application provide an indication information transmission method, including: A network device sends first indication information, where the first indication information is used to indicate a time domain position at which second indication information is monitored; and the network device sends the second indication information, where the second indication information includes information about a channel occupancy time of the network device and/or slot format information of one or more slots corresponding to the channel occupancy time. In an indication manner described in the embodiments of this application, a device can obtain a format in a COT in advance, so that blind detection overheads can be reduced, or the device can sleep in advance, thereby reducing energy consumption.