MUX-PDU Padding for PHY Packet Boundary Alignment

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Solution Overview

Problem

Wireless communication systems face significant losses of multiplex protocol data units (MUX-PDUs) due to errors in PHY packets received over noisy channels, as entire MUX-PDUs are often discarded when a single PHY packet is received in error, leading to inefficiencies in transmitting and receiving multimedia data like video and audio.

Innovation Solution

The solution involves generating MUX-PDUs based on PHY packet sizes, padding smaller MUX-PDUs to fit within a single PHY packet, and aligning MUX-PDUs with PHY packet boundaries to minimize data loss, ensuring that each valid MUX-PDU is sent in one or a minimum number of PHY packets, with padding bytes used to achieve the correct size without being mistaken for valid data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If MUX-PDUs are transmitted in PHY packets without size alignment, then the transmission process is simple, but data loss increases when PHY packets are received in error

Engineering Contradiction:
ImproveMUX-PDU delivery reliabilityVSAvoidMUX-PDU packing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments MUX-PDUs of variable sizes into fixed-size PHY packets by creating multiple virtual MUX-PDUs that conform to the PHY packet size. Each virtual MUX-PDU is constructed by combining one or more actual MUX-PDUs with padding, ensuring that each segment fits exactly into one PHY packet without overflow or truncation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter of MUX-PDU size from variable to fixed by padding smaller MUX-PDUs with null MUX-PDUs and padding bytes until they reach the PHY packet size. This parameter transformation ensures that all MUX-PDUs have uniform size equal to the PHY packet size, simplifying the transmission process and reducing data loss.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If smaller MUX-PDUs are sent as-is without padding, then the transmission process is efficient, but PHY packets are not fully utilized and data loss occurs

Engineering Contradiction:
ImprovePHY packet utilization efficiencyVSAvoidMUX-PDU delivery reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary padding of MUX-PDUs before transmission to ensure they fill the PHY packet completely. By pre-adding null MUX-PDUs and padding bytes to smaller MUX-PDUs, the system ensures that each transmitted PHY packet is fully utilized, eliminating wasted space and reducing the likelihood of data loss.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If MUX-PDUs are padded to fit PHY packet size, then data loss is minimized, but the complexity of processing increases

Engineering Contradiction:
ImproveMUX-PDU delivery reliabilityVSAvoidMUX-PDU generation ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements self-service by having the MUX-PDU generation process automatically handle padding based on the PHY packet size. The system self-adjusts by creating the appropriate number of null MUX-PDUs and padding bytes without requiring external intervention, making the complex padding process transparent and automated.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP1917809B1Transmission of multiplex protocol data units in physical layer packets
Publication Date: 2011.12.28 QUALCOMM INC
  • EP1917809B1 patent drawingFigure 1
  • EP1917809B1 patent drawingFigure 2
  • EP1917809B1 patent drawingFigure 3~4

AI summary

A transmitter generates MUX-PDUs for video, audio, data, and/or control streams based on a fixed PHY packet size such that all or a substantial percentage of the MUX-PDUs conform to the PHY packet size. The MUX-PDUs have variable sizes and are mapped to PHY packets such that (1) each MUX-PDU that is smaller than the PHY packet size is sent in one PHY packet and (2) each MUX-PDU that is larger than the PHY packet size is sent in a minimum number of PHY packets. Each MUX-PDU is padded with one or more null MUX-PDUs and/or one or more padding bytes, if needed, to obtain the PHY packet size. Each PHY packet is sent in one transmission time interval (TTI) to a receiver. The receiver performs the complementary processing on the received PHY packets to recover the MUX-PDUs. The receiver forwards each valid MUX-PDU and discards any padding.