PDCP Control PDU Prioritization for TCP ACK Latency

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Solution Overview

Problem

The increasing number of user equipment (UEs) in wireless communication systems requires efficient methods for transmitting and receiving uplink/downlink data and control information using limited radio resources, while also reducing latency and supporting new radio access technologies.

Innovation Solution

Implementing a method that allows for efficient communication between user equipment (UE) and base stations (BS) using narrowband communication, prioritizing TCP ACK packets as PDCP Control PDUs to reduce latency and improve throughput, and enabling effective signal transmission in systems supporting new radio access technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of user equipment (UEs) increases in a wireless communication system, then the communication capacity demand increases, but the available radio resources remain limited

Engineering Contradiction:
Improvecommunication capacityVSAvoidradio resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the PDCP layer functions by introducing separate PDCP Data PDUs and PDCP Control PDUs with distinct structures. This segmentation allows efficient handling of different data types (user data vs. control information) using optimized formats, thereby improving communication capacity while effectively utilizing limited radio resources.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If traditional PDCP protocols are used for all data types, then protocol simplicity is maintained, but latency increases for time-sensitive control information

Engineering Contradiction:
ImprovelatencyVSAvoidprotocol structure
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent introduces dynamic PDCP PDU format selection based on data type. PDCP Control PDUs use a simplified format for urgent control information like TCP ACKs, while PDCP Data PDUs use the traditional format for user data. This dynamic adaptation reduces latency for time-sensitive control information while maintaining protocol structure for other data.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies different PDCP PDU structures locally based on the specific data type being transmitted. Control information receives the optimized PDCP Control PDU format with reduced header overhead, while user data continues using the standard PDCP Data PDU format, thereby reducing latency for control information without affecting overall protocol complexity.

Inventive Principle:
Principle #3Local quality

3Productivity

If out-of-order delivery is enabled for improved throughput, then system efficiency increases, but delivery reliability decreases

Engineering Contradiction:
ImprovethroughputVSAvoiddelivery reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces an intermediary mechanism at the PDCP layer that receives out-of-order packets, buffers them temporarily, and manages their delivery. This intermediary function allows the system to accept out-of-order arrivals for improved throughput while maintaining the ability to deliver data in the correct sequence when required, thereby balancing throughput and reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3539317B1Method and device for transmitting data unit, and method and device for receiving data unit
Publication Date: 2023.04.12 LG ELECTRONICS INC
  • EP3539317B1 patent drawingFigure 1~2
  • EP3539317B1 patent drawingFigure 3
  • EP3539317B1 patent drawingFigure 4(a)~4(b)

AI summary

In the present invention, a transmitting device receives, at a packet data convergence protocol (PDCP) layer, a PDCP service data unit (SDU) from an upper layer. The transmitting device generates, at the PDCP layer, a PDCP protocol data unit (PDU) containing the PDCP SDU. The transmitting device submits, at the PDCP layer, the PDCP PDU to a lower layer. If the PDCP SDU includes a transmission control protocol (TCP) ACK packet, the PDCP layer generates a PDCP control PDU as the PDCP PDU.