LR-WPAN Coordinator Batch Wake-Up Frame Mechanism

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Solution Overview

Problem

Conventional wake-up mechanisms in low-rate wireless personal area networks (LR-WPANs) are inefficient, leading to high power consumption and low wake-up efficiency, especially when waking up multiple reduced-function devices (RFDs), as they often result in unnecessary device activation and response conflicts.

Innovation Solution

A method and apparatus that utilize a coordinator to send a wake-up broadcast frame with a wake-up indication field to wake up multiple RFDs in batches, preventing unnecessary activations and optimizing resource utilization by using a broadcast mechanism similar to multicast mode, where devices remain active for a controlled duration based on the wake-up indication field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If unicast wake-up frames are sent to multiple RFDs sequentially, then each targeted device can be woken up reliably, but the wake-up time becomes very long and wake-up efficiency is low

Engineering Contradiction:
Improvewake-up reliabilityVSAvoidwake-up time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent merges multiple unicast wake-up operations into a single broadcast wake-up frame. The coordinator sends one broadcast frame containing wake-up indications for multiple RFDs simultaneously, rather than sending separate unicast frames to each device sequentially. This combining approach maintains wake-up reliability while dramatically reducing the total wake-up time.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the wake-up indication information within the broadcast frame by using individual wake-up indication bits for each targeted RFD. This allows the system to selectively wake up only specific devices among multiple recipients, maintaining precision similar to unicast while achieving the efficiency of broadcast transmission.

Inventive Principle:
Principle #1Segmentation

2Productivity

If broadcast wake-up frames are sent to wake up multiple devices, then wake-up efficiency improves, but response conflicts occur and unnecessary devices are activated increasing power consumption

Engineering Contradiction:
Improvewake-up efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies local quality by giving each RFD a unique wake-up indication bit position in the broadcast frame. Only devices with their corresponding bit set to 1 will wake up and respond, while other devices remain in hibernation. This selective approach eliminates unnecessary device activation and reduces power consumption while maintaining high wake-up efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements feedback mechanisms where RFDs check their device identifier against the wake-up indication bits in the received broadcast frame. Only devices that match their identifier will activate and send responses, preventing response conflicts and ensuring that only necessary devices consume power.

Inventive Principle:
Principle #23Feedback

3Loss of energy

If RFDs remain in hibernation state for long periods, then energy saving is achieved, but the system cannot respond to control operations timely

Engineering Contradiction:
Improveenergy savingVSAvoidresponse speed
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

The patent uses preliminary action by pre-configuring wake-up indication bits in the broadcast frame before transmission. The coordinator prepares the selective wake-up information in advance, allowing RFDs to quickly determine upon receiving the frame whether they need to wake up, enabling timely response while maintaining energy savings during hibernation periods.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3200512B1Method, apparatus and device for waking up devices in batches
Publication Date: 2020.07.01 HUAWEI TECH CO LTD
  • EP3200512B1 patent drawingFigure 1
  • EP3200512B1 patent drawingFigure 2A
  • EP3200512B1 patent drawingFigure 2B~4

AI summary

Embodiments of the present invention disclose a method for waking up devices in batches. The method includes: generating, by a coordinator, a wake-up broadcast frame, where the wake-up broadcast frame includes a wake-up indication field, which is used to instruct multiple devices in an LR-WPAN to keep in a running state; and sending, by the coordinator, the wake-up broadcast frame at a time interval T2 within duration T1. According to technical solutions of the present invention, the coordinator can wake up some devices directionally by using the wake-up indication field in the wake-up broadcast frame. In this way, resource utilization and wake-up efficiency of the coordinator are improved, so that channel utilization and performance of the LR-WPAN are improved.