Selective Application Layer FEC in Mixed Unicast Multicast 5G

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Solution Overview

Problem

In 5G wireless communication networks, applying higher layer Forward Error Correction (FEC) is inefficient when unicast transmission uses hybrid automatic repeat request (HARQ) or radio link control (RLC) retransmissions, as it redundantly transmits additional bits over the air, whereas lower layer retransmissions are more efficient.

Innovation Solution

The method involves determining whether unicast or multicast/broadcast transmission is used in a Radio Access Network (RAN) and selectively transmitting application layer FEC only when necessary, utilizing lower layer error correction mechanisms like HARQ or RLC retransmissions for unicast, and avoiding redundant higher layer FEC transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If higher layer FEC is applied in unicast transmission, then data integrity is improved, but transmission efficiency deteriorates due to redundant bits

Engineering Contradiction:
Improvedata integrityVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the FEC application parameter based on transmission mode detection. When unicast transmission is detected (through RLC entity identification or PDU structure analysis), the system disables application layer FEC by setting the FEC indicator to indicate no FEC is applied. When multicast/broadcast is detected, application layer FEC is enabled. This dynamic parameter adjustment resolves the contradiction by applying FEC only when necessary.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If application layer FEC is transmitted for all flows, then error protection is improved, but network bandwidth consumption increases

Engineering Contradiction:
Improveerror protectionVSAvoidnetwork bandwidth
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies different error protection strategies to different transmission flows based on their local characteristics. By analyzing the RLC entity type or PDU structure of each flow, the system identifies whether it is unicast or multicast/broadcast and applies FEC selectively. This local quality approach ensures that FEC is applied only to multicast/broadcast flows where it is needed, while unicast flows rely on lower layer retransmission mechanisms.

Inventive Principle:
Principle #3Local quality

3Productivity

If lower layer retransmission mechanisms are used, then transmission efficiency is improved, but complexity of error correction increases

Engineering Contradiction:
Improvetransmission efficiencyVSAvoiderror correction complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the error correction function into two distinct layers: lower layer retransmission (HARQ/RLC) for unicast transmissions and application layer FEC for multicast/broadcast transmissions. This segmentation allows each layer to use the most appropriate error correction mechanism for its specific requirements, avoiding the need for a single complex system that must handle all cases.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3881459B1Method and apparatus for efficient delivery of source and forward error correction streams in systems supporting mixed unicast multicast transmission
Publication Date: 2023.12.13 NOKIA TECHNOLOGIES OY
  • EP3881459B1 patent drawingFigure 1
  • EP3881459B1 patent drawingFigure 2
  • EP3881459B1 patent drawingFigure 3

AI summary

A method, apparatus and computer program product receive an application flow comprising a source flow and a supplementary flow from a core network. The method, apparatus and computer program product receive a flow payload indication from the core network. The method, apparatus and computer program product determine whether the application flow is to be transmitted via a unicast transmission or a multicast transmission. The method, apparatus and computer program product determine whether the supplementary flow is droppable based on the flow payload indication and whether the application flow is to be transmitted via a unicast transmission or a multicast transmission. The method, apparatus and computer program product cause only the source flow to be transmitted in a circumstance where the supplementary flow is droppable.