Per-Slice QoS Constraint Signaling for CU/DU MAC Scheduling

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Solution Overview

Problem

Current 5G networks face challenges in complying with service level agreements (SLAs) due to constraints related to individual dedicated radio bearers (DRBs), which limit operational flexibility and make it difficult to align network operations with varying quality of service (QoS) requirements across different network slices.

Innovation Solution

Implementing per-slice QoS constraints communicated from a centralized unit (CU) to the MAC scheduler of a distributed unit (DU) via the CU/DU interface, allowing for improved alignment with SLAs and enhanced operational flexibility by managing QoS at the network slice level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If per-slice QoS constraints are implemented at the network slice level, then network flexibility and SLA alignment are improved, but device complexity increases

Engineering Contradiction:
Improvenetwork flexibilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments QoS management at the network slice level rather than at the individual radio bearer level. The CU/DU interface is introduced to separate control plane functions, allowing per-slice QoS constraints to be communicated from the centralized unit to the distributed unit's MAC scheduler. This segmentation enables flexible SLA alignment while distributing complexity across hierarchical levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The CU/DU interface acts as an intermediary mechanism that communicates per-slice QoS constraints from the centralized unit to the distributed unit's MAC scheduler. This intermediary layer enables flexible QoS management without requiring complex direct control mechanisms, resolving the contradiction between flexibility and complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If QoS management is performed at the radio bearer level, then implementation simplicity is maintained, but alignment with varying SLA requirements across network slices becomes difficult

Engineering Contradiction:
Improveimplementation simplicityVSAvoidSLA alignment
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments QoS management from the radio bearer level to the network slice level. By introducing per-slice QoS constraints communicated through the CU/DU interface, the system maintains implementation simplicity at the slice level while achieving precise SLA alignment. The MAC scheduler in the DU receives slice-level constraints and applies them appropriately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions QoS management from a one-dimensional radio bearer level to a multi-dimensional network slice level. This dimensional change allows simultaneous management of multiple slices with different SLA requirements while maintaining a unified implementation framework through the CU/DU interface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3827619B1Transmission of network slicing constraints in wireless networks
Publication Date: 2025.09.17 NOKIA TECHNOLOGIES OY
  • EP3827619B1 patent drawingFigure 1
  • EP3827619B1 patent drawingFigure 2
  • EP3827619B1 patent drawingFigure 3

AI summary

A 5G network communicates per-slice constraints for QoS parameter values froma centralized unit (CU) to a MAC scheduler of a distributed unit (DU). The CU communicates these per-slice constraints, rather than or in addition to per-DRB constraints, to the MAC scheduler over the CU/DU interface. In some implementations, the CU/DU interface is an F1 air interface as defined in specification 38.473 in the 3GPP standard. In some implementations, the DU provides per-slice performance feedback over the CU/DU interface. Based on such feedback, the CU may adjust the per-slice QoSconstraints.