Wake-Up Signal Bitmap Mapping for Fair Terminal Activation

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Solution Overview

Problem

In wireless communication systems, the use of wake-up signals (WUS) for terminal devices results in conflicts among multiple devices sharing the same bit in a bitmap, leading to unfairness in waking up terminal devices, which increases power consumption and complexity.

Innovation Solution

A method and apparatus to pseudo-randomly distribute the locations of wake-up signal indications based on terminal device identification and time information, ensuring each device has a unique or pseudo-unique location within the indication information, thereby achieving fairness among devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple terminal devices share the same bitmap bit for WUS indication, then the bitmap size is reduced, but WUS conflicts occur and fairness is degraded

Engineering Contradiction:
Improvebitmap sizeVSAvoidWUS indication fairness
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the single bitmap into multiple bitmaps, where each bitmap corresponds to a specific time period. This segmentation allows different terminal devices to be indicated in different bitmaps, reducing conflicts while maintaining a compact overall structure. The segmentation resolves the contradiction by distributing the indication burden across multiple smaller units rather than forcing all devices into one large bitmap or one contested bit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic selection of bitmaps based on time periods and terminal device characteristics. Instead of a static bitmap assignment, the system dynamically determines which bitmap to use for each device based on current time period information. This dynamic approach allows flexible allocation that adapts to changing conditions, improving fairness while maintaining efficient bitmap usage.

Inventive Principle:
Principle #15Dynamics

2Reliability

If terminal devices periodically wake up to detect DCI, then data communication is ensured, but power consumption increases

Engineering Contradiction:
Improvedata communicationVSAvoidterminal device power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses WUS as a preliminary action before the actual DCI transmission. The network device sends WUS in advance to indicate whether DCI will be transmitted, allowing terminal devices to avoid waking up unnecessarily. This preliminary indication mechanism ensures that devices only activate for full detection when actually needed, reducing power consumption while maintaining reliable communication when data is present.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements partial detection by having terminal devices perform only WUS detection instead of full DCI detection in many cases. WUS detection requires less processing and can be performed with lower power consumption. This partial action approach is sufficient for the majority of cases where no data transmission is needed, while full detection is reserved for cases where WUS indicates data is present.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If WUS detection is performed by terminal devices, then power consumption is reduced compared to PDCCH detection, but detection complexity remains

Engineering Contradiction:
Improvepower consumptionVSAvoiddetection complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies different detection requirements to different terminal devices based on their characteristics and current state. Not all devices need to perform the same level of detection - the system tailors the detection complexity to each device's local needs. This local quality approach allows devices with simpler requirements to use lighter detection methods while more capable devices can handle more complex detection when necessary.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the detection parameters by introducing multiple bitmaps with different characteristics. Instead of a single uniform detection process, the system varies detection parameters based on which bitmap is being monitored and what time period is relevant. This parameter changes approach allows optimization of detection complexity for different scenarios while maintaining energy efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4024961B1Indicator information sending method and apparatus
Publication Date: 2026.04.22 HUAWEI TECH CO LTD
  • EP4024961B1 patent drawingFigure 1
  • EP4024961B1 patent drawingFigure 2
  • EP4024961B1 patent drawingFigure 3~4

AI summary

This application discloses a method and an apparatus for sending indication information, relates to the communication field, and is used to pseudo-randomize WUSs of terminal devices, to achieve fairness for all the terminal devices as much as possible. The method for sending the indication information includes: A network device determines a location of first indication information in at least one piece of second indication information based on first information. The first information includes at least one of identification information of a first terminal device and time information of a first preset time period, the first terminal device is one of to-be-woken-up terminal devices that are within a discontinuous reception outside active time period, and the first indication information indicates the first terminal device to enter an inside active time period within a preset time period. The network device sends the second indication information on a time-frequency resource corresponding to the first preset time period. The second indication information indicates at least one to-be-woken-up terminal device to enter an inside active time period within a corresponding time period.