WLAN Communication Devices: PPDU Truncation and Padding for Low-Latency Data

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Solution Overview

Problem

Existing WLAN systems face challenges in handling latency-sensitive data units when non-latency-sensitive data transmission is already in progress, leading to unacceptable delays for the latency-sensitive data due to the fixed duration of PPDU transmissions.

Innovation Solution

The solution involves truncating ongoing PPDU transmissions and adding modulation and encoding padding bits to complete the data units, allowing for immediate transmission of latency-sensitive data without significant data loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ongoing PPDU transmission is required to finish before a new PPDU transmission can be initiated, then the transmission reliability is improved, but the latency of latency-sensitive data increases unacceptably

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidlatency of latency-sensitive data

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the ongoing PPDU transmission into two parts: the already transmitted portion and the remaining portion. By truncating the ongoing transmission and separately transmitting the remaining data in a new PPDU, the system allows latency-sensitive data to be transmitted immediately in the new PPDU while the remaining non-latency-sensitive data follows, thus resolving the contradiction between transmission reliability and latency.

Inventive Principle:

Principle #1Segmentation

2Productivity

If a long transmit time is used for PPDU, then the communication efficiency is improved, but the ability to handle latency-sensitive data deteriorates

Engineering Contradiction:

Improvecommunication efficiencyVSAvoidresponse time for latency-sensitive data

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent introduces dynamic transmission time allocation by allowing the PPDU transmit time to be adjusted based on data urgency. Latency-sensitive data can trigger an immediate PPDU transmission with shorter duration, while non-latency-sensitive data can utilize longer transmissions for efficiency. This dynamic adaptation resolves the contradiction between communication efficiency and response time.

Inventive Principle:

Principle #15Dynamics

3Loss of time

If the PPDU transmission is truncated to enable immediate transmission of latency-sensitive data, then the latency is reduced, but data loss may occur

Engineering Contradiction:

Improvequeuing delay for latency-sensitive dataVSAvoiddata loss of ongoing transmission

Core Design Contradiction:

Loss of timeVSLoss of information

Solution Approach 1:

The patent discards the remaining portion of the truncated PPDU transmission and recovers it by transmitting the remaining data in a new PPDU. This ensures that no data is lost while enabling immediate transmission of latency-sensitive data, thus resolving the contradiction between reducing latency and preventing data loss.

Inventive Principle:

Principle #34Discarding and recovering

Data Source

PatentEP4085582B1Communication devices and methods

Publication Date: 2025.07.16 SONY GROUP CORP

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AI summary

Communication device for transmitting data to another communication device, the communication device comprising circuitry configured to obtain a truncation notification indicating that an ongoing transmission of a data unit is to be truncated; in response to the truncation notification, determine, based on the number of unprocessed modulation input bits of the data unit, a remaining bit length of a modulation input block, and perform padding to add a number of modulation padding bits corresponding to the determined remaining bit length of a modulation input block to the unprocessed modulation input bits to obtain a complete modulation input block; modulate the complete modulation input block to obtain a modulation output block; and transmit a transmit data stream containing the obtained modulation output block.