NB-IoT Multi-Carrier Load Balancing via UE Measurement Reports

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Solution Overview

Problem

The NarrowBand Internet-of-Things (NB-IoT) standard lacks efficient multi-carrier operation across different radio frequency bands and cells, leading to congestion in some frequency layers while others remain underutilized, due to lack of signal condition awareness by the base station, unsupported frequency changes, and complex configuration requirements.

Innovation Solution

A method that allows the base station to distribute UEs across different NB-IoT carriers and cells by using measurement reports from UEs to optimize signal conditions, configuring additional carriers, and introducing extended signaling for radio link monitoring and power control, enabling efficient multi-carrier operation across frequency bands and cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multi-carrier operation is configured in connected mode, then spectrum resource utilization can be improved, but frequency layers become congested while others remain underutilized due to UE selecting frequency layer in idle mode

Engineering Contradiction:
Improvespectrum resource utilizationVSAvoidfrequency layer distribution
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The network performs preliminary actions by configuring multiple carriers and providing carrier indication information to the UE before the UE needs to access the network. This allows the network to pre-prepare multiple frequency layers for potential use, enabling dynamic carrier selection during connection establishment based on network conditions rather than UE autonomous selection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention implements feedback mechanisms where the network monitors signal conditions and congestion levels on different frequency layers, then uses carrier indication information in downlink messages to guide the UE's uplink transmission carrier selection. This closed-loop feedback enables balanced load distribution across multiple carriers.

Inventive Principle:
Principle #23Feedback

2Device complexity

If the base station is unaware about signal conditions at the UE, then device complexity is reduced, but efficient multi-carrier operation cannot be achieved

Engineering Contradiction:
Improvesignal condition monitoringVSAvoidmulti-carrier operation efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent introduces measurement reports as an intermediary mechanism. The UE performs measurements and reports them to the network, allowing the base station to become aware of signal conditions without requiring complex monitoring infrastructure. These measurement reports serve as the intermediary information carrier that enables informed carrier selection decisions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the need for complex base station signal monitoring mechanisms with a simpler reporting-based approach. Instead of the base station actively measuring and tracking signal conditions, the system substitutes this with UE-performed measurements and periodic reports, reducing base station complexity while maintaining awareness of signal conditions.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If connected mode mobility is not defined, then device complexity is kept low, but efficient use of multiple frequency layers is not possible

Engineering Contradiction:
Improvemobility managementVSAvoidfrequency layer utilization
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The invention implements a partial mobility solution that provides just enough carrier switching capability for frequency layer optimization without implementing full connected mode mobility. The carrier indication information mechanism enables selective carrier switching for uplink transmissions based on network conditions, achieving frequency layer efficiency without the complete overhead of standard mobility management procedures.

Inventive Principle:
Principle #16Partial or excessive action

4Ease of operation

If redirection procedure is used to allocate UE to another carrier frequency, then frequency layer congestion can be relieved, but additional connection establishment is required which increases power consumption

Engineering Contradiction:
Improvecongestion managementVSAvoidUE power consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The network configures multiple carriers and provides carrier indication information in advance during connection establishment or reconfiguration. This preliminary configuration allows the UE to switch carriers without initiating a new connection establishment procedure, as the carrier switching is based on pre-configured parameters and network instructions rather than requiring full re-connection.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3364589B1Flexible NB-iot multi-carrier operation across radio frequency bands
Publication Date: 2023.01.25 SHENZHEN GOODIX TECH CO LTD
  • EP3364589B1 patent drawingFigure 1~2

AI summary

The invention discloses a method for improving NarrowBand Internet-of-Things radio network utilization by more efficiently and flexibly allocating available frequency spectrum resources to an UE. The objective to provide a method which allows efficient NB-IoT multi-carrier operation across different radio frequency bands or NB-IoT/ LTE mother cells will be solved by a method for improving NarrowBand Internet of Things (NB-IoT) radio network utilization by more efficiently and flexibly allocating available frequency spectrum resources to an UE, wherein system information messages and/or dedicated signaling exchanged between an eNodeB and the UE are extended by specific parameters, setups and requests, so that multi-carrier operations are performable across all radio frequency bands even if the UE is already connected to the eNodeB.