Slave Device Relay for Low Energy Audio Broadcast

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Solution Overview

Problem

Short-range wireless communications in WPANs, such as Bluetooth and Bluetooth Low Energy, are susceptible to errors due to noisy and congested transmission mediums, leading to degraded performance and user experience, particularly in broadcast models where retransmissions are unnecessary, increasing the cost of maintaining error time.

Innovation Solution

Offload retransmission time from the master device to slave devices, such as earbuds, to improve audio robustness by allowing retransmissions only when needed, reducing the number of unnecessary retransmissions in broadcast models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retransmissions are performed in broadcast models, then audio robustness is improved, but error time cost increases due to pre-allocated time slots being utilized regardless of need

Engineering Contradiction:
Improveaudio robustnessVSAvoiderror time cost
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic retransmission where slave devices actively request retransmission of missed packets from other slave devices that successfully received them. This transforms the static pre-allocated time slot model into a dynamic on-demand model, allowing retransmissions to occur only when actually needed rather than reserving time slots regardless of packet loss conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Slave devices perform self-service by autonomously identifying missed packets and requesting their retransmission from peer slave devices. This eliminates the need for the master device to manage all retransmissions and reduces unnecessary retransmission overhead, as each slave device handles its own packet recovery needs through inter-slave communication.

Inventive Principle:
Principle #25Self-service

2Reliability

If the master device performs all retransmissions, then audio robustness is improved, but device complexity and processing load increase

Engineering Contradiction:
Improveaudio robustnessVSAvoidmaster device processing load
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the retransmission responsibility from the master device and distributes it among multiple slave devices. Each slave device that successfully receives a packet can potentially serve as a retransmission source for other slave devices that miss the packet. This segmentation reduces the master device's processing load and distributes the robustness function across the network.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Successfully receiving slave devices act as intermediaries for packet retransmission. Instead of the master device directly retransmitting to all slave devices, the system uses peer slave devices as mediators to forward packets to those that missed them, reducing the master device's complexity and processing requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If pre-allocated time slots are used for retransmissions, then audio robustness is improved, but productivity decreases due to reserved time slots reducing available transmission capacity

Engineering Contradiction:
Improveaudio robustnessVSAvoidtransmission capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements periodic retransmission requests where slave devices attempt to recover missed packets at regular intervals through inter-slave communication. This periodic action allows the system to maintain robustness without continuously reserving time slots, as retransmissions occur in structured periodic attempts rather than through continuous pre-allocated resources.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4118774B1Broadcast relay piconet for low energy audio
Publication Date: 2026.01.21 QUALCOMM INC
  • EP4118774B1 patent drawingFigure 1
  • EP4118774B1 patent drawingFigure 2
  • EP4118774B1 patent drawingFigure 3A

AI summary

This disclosure describes a first slave device that transmits information to a second slave device indicating that a first data packet was improperly received from a master device, so that a corresponding data packet may be relayed from the second slave device to the first slave device. In an aspect, the second slave device may receive a first data packet followed by an indication that the first slave device improperly received the first data packet, where the second slave device is configured to relay the first data packet to the first slave device in response thereto. In another aspect, the second slave device may receive a request to listen for a separate data stream of the first slave device based on a first data packet being improperly received by the first slave device and transmit a second data packet of the separate data stream to the first slave device.