Muting TDD Configurations for PN-NPN Coexistence

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Solution Overview

Problem

The coexistence of public and non-public 5G networks is hindered by adjacent channel interference due to different Time Division Duplex (TDD) configurations, leading to performance degradation and potential interference exceeding regulatory limits.

Innovation Solution

Network nodes selectively mute conflicting downlink or uplink transmissions based on interference detection, with specific muting restricted to overlapping coverage areas or beams, and strategic placement of small cells to mitigate interference while maintaining transmission opportunities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If NPN and public macro networks are deployed on separate frequency channels, then interference between the networks is reduced, but spectrum utilization efficiency decreases and deployment flexibility is limited

Engineering Contradiction:
ImproveinterferenceVSAvoiddeployment flexibility
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different spatial regions. Small cells deployed within or near NPN coverage areas are configured with different TDD configurations than macro cells. Specifically, small cells in NPN areas mute downlink transmissions during NPN uplink slots to avoid interference, while macro cells maintain standard operation. This localized differentiation allows coexistence without requiring separate frequency channels throughout the entire deployment area.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics through dynamic TDD configuration adjustment. Network nodes can dynamically switch between different TDD configurations based on local interference conditions and deployment requirements. The system can adaptively select between Config 1 (balanced UL-DL) and Config 2 (DL-heavy) depending on whether the area requires NPN coexistence or standard public network operation, enabling flexible spectrum utilization.

Inventive Principle:
Principle #15Dynamics

2Reliability

If NPN uses different TDD configuration to meet URLLC latency requirements, then latency performance is improved, but adjacent channel interference with public network increases

Engineering Contradiction:
Improvelatency performanceVSAvoidadjacent channel interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by differentiating the treatment of different spatial regions. Small cells deployed within or near NPN coverage areas are configured with different TDD configurations than macro cells. Specifically, small cells in NPN areas mute downlink transmissions during NPN uplink slots to avoid interference, while macro cells maintain standard operation. This localized differentiation allows coexistence without requiring separate frequency channels throughout the entire deployment area.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces small cells as intermediary elements between the NPN and public macro network. These small cells act as buffers that can be configured with protective TDD settings, muting transmissions during conflicting slots. By placing small cells at the interface between NPN and public network coverage, the system mediates interference while allowing both networks to operate with their optimal TDD configurations in their respective core areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If small cells are deployed to match NPN coverage area, then interference mitigation is improved, but network complexity and deployment cost increase

Engineering Contradiction:
ImproveinterferenceVSAvoidnetwork complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies partial action by deploying small cells only in specific locations where interference mitigation is most needed, rather than throughout the entire NPN coverage area. Small cells are strategically placed at the interface between NPN and public network coverage, or in areas with highest interference measurements. This selective deployment reduces the total number of small cells required while still providing effective interference protection, balancing complexity reduction with interference mitigation effectiveness.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4085713B1Method for improving PN-NPN coexistence
Publication Date: 2024.10.30 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP4085713B1 patent drawingFigure 1
  • EP4085713B1 patent drawingFigure 2
  • EP4085713B1 patent drawingFigure 3

AI summary

A method, system and apparatus for coexistence of a public network and a non-public network are disclosed. According to one aspect, a method includes selectively muting a downlink transmission to a public network (PN) based at least in part on whether the downlink transmission interferes with a non-public network (NPN) uplink transmission. According to another aspect, a method includes selectively muting an uplink transmission from the NPN based at least in part on whether the uplink transmission interferes with a public network (PN) downlink transmission.