WURx Channel Switching for Low Power Multi-User Transmission

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The implementation of Wake-Up Radio (WUR) transmissions on multiple channels and Frequency Division Multiple Access (FDMA) technology faces challenges in practical application, particularly in ensuring efficient wake-up of multiple devices while maintaining low latency and extending battery life in Internet-of-Things (IoT) applications, where existing solutions struggle with efficient frequency resource utilization and device synchronization.

Innovation Solution

A communication apparatus and method that includes a Primary Connectivity Radio (PCR) circuitry, Wake-Up Receiver (WURx) circuitry, and a controller, which receives WUR operation elements from an Access Point (AP) to switch between WUR channels for efficient beacon and wake-up frame transmission, utilizing FDMA to improve transmission efficiency by defining multiple WUR channels within a single 20 MHz channel and using Null signals to prevent misdetection by legacy devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If WUR transmissions are performed on multiple channels using FDMA, then transmission efficiency and battery life are improved, but device synchronization and frequency resource utilization become more complex

Engineering Contradiction:

Improvetransmission efficiencyVSAvoiddevice synchronization complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the 20 MHz channel into multiple WUR channels (e.g., 4 MHz sub-channels) and assigns different WUR frames to different channels. This segmentation allows simultaneous transmissions on multiple channels, improving throughput while maintaining manageable complexity through structured channel assignment and synchronization mechanisms.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic channel selection and switching mechanisms where the WURx circuitry can switch between different WUR channels based on received indications from the AP. This dynamic adaptation allows the system to optimize resource utilization in real-time while maintaining synchronization through coordinated channel switching at both AP and station sides.

Inventive Principle:

Principle #15Dynamics

2Productivity

If multiple WUR channels are defined within a single 20 MHz channel, then frequency resource utilization is improved, but legacy device compatibility and signal detection become problematic

Engineering Contradiction:

Improvefrequency resource utilizationVSAvoidlegacy device misdetection

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces Null signals as intermediary elements that are transmitted on WUR channels alongside or instead of actual WUR frames. These Null signals serve as mediators that prevent legacy devices from misinterpreting the multi-channel structure as continuous data transmissions, thereby avoiding misdetection while enabling efficient frequency resource utilization through actual WUR frame transmissions on assigned channels.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the WURx switches channels to receive WUR beacon frames, then synchronization is maintained, but scan latency increases

Engineering Contradiction:

Improvesynchronization reliabilityVSAvoidscan latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary channel switching before the expected WUR beacon transmission time (TWBTT). The WURx circuitry switches to the indicated WUR channel in advance of the beacon arrival, allowing it to be ready to receive the beacon frame immediately at TWBTT without additional switching delay. This preliminary action maintains synchronization reliability while minimizing scan latency.

Inventive Principle:

Principle #10Preliminary action

4Use of energy by moving object

If FDMA transmission is used to wake up multiple devices, then battery life is extended, but transmission reliability and frame detection become more challenging

Engineering Contradiction:

Improvebattery lifeVSAvoidframe detection reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements feedback mechanisms where receiving stations send acknowledgments or status information back to the AP about their wake-up status and channel reception quality. This feedback allows the AP to adjust its FDMA transmission strategy, retransmit frames if necessary, and optimize channel assignments, thereby maintaining high transmission reliability while extending battery life through efficient multi-channel utilization.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11659489B2Communication apparatus and communication method for low power multi-user transmission

Publication Date: 2023.05.23 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

The present disclosure provides a communication apparatus that comprises a Primary Connectivity Radio (PCR) capable of transmitting and receiving wireless signals; a low power Wake Up Receiver (WURx) capable of receiving Wake-Up Radio (WUR) signals, the WURx being configured to receive WUR signals on a first WUR channel assigned to the apparatus by an Access Point (AP); a WUR channel scheduler programmed to configure the WURx to switch to a second WUR channel designated as a broadcast WUR channel by the AP, when the first WUR channel is different from the second WUR channel, wherein the channel switch occurs in time for the WURx to receive the scheduled WUR Beacon frames from the AP.