Dual Connectivity in Unlicensed Spectrum Networks

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Solution Overview

Problem

Current dual connectivity technologies face challenges when implementing dual connectivity between master and secondary base stations belonging to different operators, particularly in scenarios involving standalone networks operating in unlicensed spectra, as they are designed assuming both belong to the same operator and network.

Innovation Solution

The solution involves designing dual connectivity systems where a standalone network operating in an unlicensed spectrum provides airlink resources as a secondary node, with a base station in a licensed spectrum acting as the master node, allowing for dual connectivity between LTE-MF or NR-MF networks, and enabling communication procedures tailored to the level of support at higher or lower layers of radio access technology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If dual connectivity is implemented between master and secondary base stations belonging to different operators using the same existing dual connectivity design, then additional radio resources can be provided, but the system reliability deteriorates because the design assumes both base stations belong to the same operator and network

Engineering Contradiction:
Improveradio resourcesVSAvoidsystem reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent segments the dual connectivity system into two distinct parts: a licensed network portion (master base station) and an unlicensed network portion (secondary base station). This segmentation allows each part to operate independently with its own signaling procedures, enabling cross-operator connectivity while maintaining reliability by not assuming unified network ownership.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary signaling mechanism where the master base station relays certain control signals between the user equipment and the secondary base station. This intermediary approach enables coordination between different operators' networks without requiring direct trust or unified management, thus maintaining system reliability across operator boundaries.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a standalone network operating in unlicensed spectrum is used as a secondary node, then deployment flexibility and network capacity are improved, but the device complexity increases due to asynchronous communication procedures and reduced registration requirements

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

Solution Approach 1:

The patent implements dynamic signaling procedures where the master base station adapts its signaling behavior based on the operational state of the standalone unlicensed network. The system dynamically adjusts registration requirements and communication procedures according to whether the secondary node is in synchronized or asynchronous mode, allowing deployment flexibility while managing complexity through conditional logic.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes key operational parameters such as registration requirements and signaling frequency based on the network configuration. When using standalone unlicensed networks, the system modifies parameters like registration frequency and control signal intervals to reduce overhead, thereby improving adaptability while the UE manages the increased complexity through parameter-based configuration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3677074B1Dual connectivity with a network that utilizes an unlicensed frequency spectrum
Publication Date: 2021.09.15 QUALCOMM INC
  • EP3677074B1 patent drawingFigure 1
  • EP3677074B1 patent drawingFigure 2A~2D
  • EP3677074B1 patent drawingFigure 3

AI summary

Aspects presented herein provide for dual connectivity with a standalone service provider in the unlicensed spectrum. A first base station may receive, from a UE, an indication of a capability for standalone operation in a first RAT that utilizes an unlicensed frequency spectrum and a dual connectivity capability involving the first RAT and a second RAT that utilizes a licensed frequency spectrum, wherein dual connectivity comprises the UE being connected to a master base station on a first frequency and a secondary base station on a second frequency at a same time. The first base station may signal a first set of procedures for dual connectivity when the level of support at the first base station is at higher layers of the first RAT and may signal a second set of procedures when the level of support at the first base station extends to lower layers of the first RAT.