Distributed Unit Context Retention for Low-Latency Uplink Data

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Solution Overview

Problem

In wireless communication systems like LTE and NR, uplink data transmission latency and power consumption are increased when a terminal device transitions to an inactive state due to the release of context by the network side device, leading to inefficiencies in data handling and resource management.

Innovation Solution

The distributed unit of the network side device stores the context of the terminal device in an inactive state, including air interface and F1 contexts, allowing immediate data transmission and reducing monitoring latency and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the DU releases the context of the terminal side device when switching to inactive state, then network resource management is optimized, but uplink data transmission latency increases and power consumption increases

Engineering Contradiction:
Improvenetwork resource management efficiencyVSAvoiduplink data transmission latency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The DU performs preliminary actions by storing essential context information (air interface context and F1 context) before the terminal device transitions to inactive state. This pre-stored context includes data transmission channel information, enabling the DU to immediately process uplink data without waiting for context establishment, thus reducing transmission latency while maintaining network resource management efficiency

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the DU releases the context of the terminal side device when switching to inactive state, then network resource management is optimized, but power consumption of terminal side device increases

Engineering Contradiction:
Improvenetwork resource management efficiencyVSAvoidpower consumption of terminal side device
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The DU pre-stores context information including data transmission channel configuration before the terminal enters inactive state. This allows the terminal to send uplink data immediately without performing context establishment procedures, reducing the terminal's active processing time and power consumption while the network maintains efficient resource management

Inventive Principle:
Principle #10Preliminary action

3Loss of time

If the DU stores the context of the terminal side device in inactive state, then uplink data transmission latency is reduced, but network resource management complexity increases

Engineering Contradiction:
Improveuplink data transmission latencyVSAvoidnetwork resource management complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The DU extracts and stores only the essential context information needed for immediate data transmission (air interface context and F1 context including data transmission channel) while releasing other context elements. This selective extraction reduces the storage burden and management complexity while enabling fast uplink data transmission without full context maintenance

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The DU applies different quality levels to different context elements: essential transmission-related context is preserved in high detail for immediate data handling, while other context elements are released or simplified. This local differentiation maintains transmission performance while reducing overall management complexity

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4075880B1Context management method and apparatus
Publication Date: 2025.07.30 HUAWEI TECH CO LTD
  • EP4075880B1 patent drawingFigure 1~3
  • EP4075880B1 patent drawingFigure 4
  • EP4075880B1 patent drawingFigure 5

AI summary

A context management method and an apparatus are provided. The method includes: When a distributed unit DU of a network side device receives a first message from a centralized unit CU of the network side device, the distributed unit DU of the network side device may store a context of the terminal side device in an inactive state. The first message includes a second message, and the second message is used to indicate the terminal side device to enter the inactive (inactive) state and release a connection to the network side device. According to the method provided in this application, when storing (or keeping) the context of the terminal side device in the inactive state, the DU of the network side device can receive uplink data from the terminal side device in the inactive state based on information such as the context, to reduce overheads and power consumption caused when the terminal side device sends signaling.