Dual-Connectivity Rateless Coding for Transmission Delay

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Solution Overview

Problem

In dual-connectivity scenarios, user equipment experiences increased transmission delays and reduced throughput due to differences in signal quality between macro and small eNodeBs, leading to data reordering and retransmissions, which can cause delays and data loss.

Innovation Solution

Implementing a dual-connectivity rateless coding (DCRC) layer between the PDCP and RLC layers for network coding, where user plane data is encoded into multiple blocks, with some blocks sent through one access network device and others directly to the terminal device, allowing for direct decoding without reordering, thus reducing waiting delays and improving throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE enables a reordering function to receive data in sequence through different links, then data sequence integrity is improved, but transmission delay increases

Engineering Contradiction:
Improvedata sequence integrityVSAvoidtransmission delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the reordering function from the UE and relocates it to the network side (specifically the PDCP layer in the MeNB). This allows the UE to receive data packets asynchronously from different access nodes without maintaining complex reordering buffers, thereby reducing transmission delay while the network side ensures proper sequence reconstruction before delivering data to the upper layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary reordering mechanism at the network side that mediates between the asynchronous data arrival from multiple access nodes and the requirement for in-sequence data delivery. This intermediary layer absorbs the reordering delay at the network side rather than at the UE, effectively reducing the impact on UE transmission delay.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the MeNB and SeNB retransmit data due to poor channel quality, then data reliability is improved, but transmission delay increases

Engineering Contradiction:
Improvedata delivery reliabilityVSAvoidretransmission delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the MeNB perform advance reordering and sequence management before data is forwarded to the UE. By pre-organizing data packets and managing sequences at the network side before transmission, the system reduces the likelihood of retransmissions caused by out-of-sequence delivery, thereby improving reliability while minimizing retransmission delays.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the UE reports reception status and sequence information to the network side. This feedback enables the network to efficiently manage retransmissions at the source (MeNB/SeNB) based on actual UE reception conditions, reducing unnecessary retransmissions and optimizing the balance between reliability and delay.

Inventive Principle:
Principle #23Feedback

3Productivity

If network coding is implemented at the PDCP layer, then data transmission efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidnetwork coding implementation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces a DCRC layer as an intermediary between the PDCP layer and RLC layer specifically for implementing network coding. This dedicated intermediate layer isolates the complexity of network coding operations from both the PDCP and RLC layers, allowing efficient data transmission through network coding while containing the increased device complexity within a specialized layer that handles only coding-related functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3576329B1Communication method and device
Publication Date: 2022.06.22 HUAWEI TECH CO LTD
  • EP3576329B1 patent drawingFigure 1~2
  • EP3576329B1 patent drawingFigure 3~4
  • EP3576329B1 patent drawingFigure 5a~5b

AI summary

Embodiments of the present invention provide a communication method and a communications device. The method includes: obtaining, by a first access network device, a first data block; performing network coding on the first data block to generate a plurality of first encoded data blocks; and performing, by the first access network device, offload processing on at least one first encoded data block in the plurality of first encoded data blocks. The offload processing includes: sending a part of the at least one first encoded data block to a second access network device, and directly sending, by using an air interface, another part of the at least one first encoded data block to the terminal device. The embodiments of the present invention can shorten a data transmission delay in a dual-connectivity scenario and improve a throughput of UE.