Base Station Conformance Testing for LTE-NR DSS Alignment

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Solution Overview

Problem

Current base station testing arrangements do not facilitate combined LTE and NR BS conformance testing with Dynamic Spectrum Sharing (DSS) operation, as defined by 3GPP test specifications, necessitating a solution for effective frequency and timing alignment between 4G LTE and 5G NR carriers.

Innovation Solution

A method and apparatus for base station conformance testing that measures and adjusts frequency and timing differences between 4G LTE and 5G NR carriers using a Pre-FFT minimization process, applying a 7.5 kHz frequency shift to the NR uplink carrier, and computes relative carrier errors to ensure alignment within specified limits, enabling DSS operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate testing arrangements are used for LTE and NR base stations, then each technology can be tested according to its specific standards, but the testing process becomes complex and time-consuming with multiple separate procedures

Engineering Contradiction:
Improvetesting accuracyVSAvoidtesting arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines separate LTE and NR base station testing procedures into a single integrated testing arrangement. The testing device is configured to simultaneously perform conformance testing for both LTE and NR technologies using unified test procedures that handle multiple radio access technologies, thereby reducing the number of separate testing arrangements needed while maintaining testing accuracy for each technology

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The testing device is designed with multi-functionality to handle both LTE and NR base station conformance testing within a single system. The device can dynamically adapt its testing procedures based on the radio access technology being tested, providing a universal testing solution that eliminates the need for technology-specific separate testing arrangements

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If frequency and timing alignment between LTE and NR carriers is not properly managed, then spectrum sharing becomes difficult, but implementing alignment mechanisms increases testing complexity

Engineering Contradiction:
Improvespectrum sharing capabilityVSAvoidalignment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements preliminary frequency and timing alignment procedures as part of the initial base station conformance testing process. The testing device verifies that the base station can properly align LTE and NR carriers before actual spectrum sharing operation begins, ensuring that alignment capabilities are established in advance rather than requiring complex real-time adjustment mechanisms

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The testing arrangement verifies that the base station can dynamically adjust frequency and timing parameters of LTE and NR carriers to achieve proper alignment. The testing device checks the base station's ability to modify these parameters in response to spectrum sharing requirements, enabling adaptability without requiring permanently fixed complex alignment mechanisms

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4427479B1Testing a base station
Publication Date: 2025.09.17 NOKIA TECHNOLOGIES OY
  • EP4427479B1 patent drawingFigure 1
  • EP4427479B1 patent drawingFigure 2
  • EP4427479B1 patent drawingFigure 3

AI summary

Methods and apparatus for base station conformance testing are disclosed. Two wireless carriers that are based on different radio technologies and dynamically share a radio spectrum are received from a base station. Frequencies and timings of the two wireless carriers are measured and a frequency difference between the measured frequencies and a timing difference between the measured timings of the two wireless carriers are then determined. It can then be determined whether the frequency and timing differences satisfy predefined criteria for acceptable frequency and timing differences.