CU-C Relocation Latency in 5G Disaggregated Access Nodes

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

5G ultra-dense networks face increased handover latency due to the need for CU-C relocation during inter-DU mobility, which is exacerbated by the separation of control and user planes in disaggregated architectures.

Innovation Solution

A method and apparatus for managing access network nodes by determining a secondary CU-C to manage control plane communications across multiple DUs, allowing for reconfiguration of data communication control interfaces to reduce latency, and selecting nodes based on traffic intensity for optimized handover performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If CU-C relocation is performed during inter-DU mobility, then control plane management is improved, but handover latency increases

Engineering Contradiction:

Improvecontrol plane managementVSAvoidhandover latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent pre-establishes backup control plane connections between DUs and alternative CU-C instances before handover is needed. When handover occurs, the DU can immediately switch to the pre-configured backup CU-C without relocation delays, as the control plane association is already in place.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a control plane intermediary mechanism where a home CU-C maintains control plane associations with multiple DUs including those in target gNBs. This intermediary enables direct control plane communication during handover, eliminating the need for CU-C relocation and reducing handover latency.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If disaggregated architecture with separated control and user planes is used, then network deployment flexibility is improved, but handover latency increases

Engineering Contradiction:

Improvenetwork deployment flexibilityVSAvoidhandover latency

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent segments the control plane functionality by separating the home CU-C from visited CU-C instances while maintaining logical control plane associations. This segmentation allows DUs to be controlled by their home CU-C even when physically located in different gNBs, enabling flexible deployment without increasing handover latency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes the home CU-C universal by enabling it to control multiple DUs across different gNBs simultaneously. This multi-functionality allows a single CU-C to manage control plane operations for DUs regardless of their physical location, maintaining deployment flexibility while eliminating handover latency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3588851B1Method for configuring an access network node and apparatus for implementing the same

Publication Date: 2023.02.01 MITSUBISHI ELECTRIC R&D CENTRE EUROPE BV

Figure 1a
Figure 1b
Figure 2

AI summary

A method for managing a first access network node in a network of a wireless communication system is proposed, which comprises: determining in the network a second central unit for a control plane of data communications between a UE and the network, CU-C, other than a first CU-C comprised in the first access network node, wherein the first access network node further comprises at least one first distributed units, DU, for data communications between the UE and the first access network node, controlled by the first CU-C, and wherein the second CU-C controls at least one second DU comprised in a second access network node; and configuring the first access network node, wherein the configuring comprises: associating at least one DU among the at least one first DU with the second CU-C.