TDD Network Node Synchronization via Terrestrial Interface

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Solution Overview

Problem

Existing synchronization methods for Time Division Duplex (TDD) systems face challenges such as high overhead and service interruptions due to air interface resource occupation, unreliable information acquisition, and compatibility issues with old base stations, especially in dynamic network topologies and indoor environments where GPS signals are unavailable.

Innovation Solution

A method and system that utilize a terrestrial interface to acquire synchronization status and level information between network nodes, allowing unsynchronized nodes to synchronize with synchronized nodes without occupying precious air interface resources, by informing and modifying synchronization status through a network node interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If air interface monitoring-based synchronization is used, then synchronization can be achieved without GPS, but air interface resources are occupied causing service interruptions

Engineering Contradiction:
Improvesynchronization capability in indoor environmentsVSAvoidservice continuity
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent introduces a terrestrial interface as an intermediary channel for synchronization information exchange between base stations. Instead of using the air interface (which carries user services), the synchronization status and level information are transmitted through a dedicated terrestrial interface, thus mediating between the need for synchronization and the need to maintain service continuity on the air interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the synchronization function from the air interface communication function. By separating synchronization information transmission (via terrestrial interface) from user data transmission (via air interface), the system can maintain synchronization without occupying air interface resources, thus avoiding service interruptions.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If synchronization status is frequently updated to adapt to dynamic network topology, then synchronization accuracy is maintained, but overhead increases

Engineering Contradiction:
Improvesynchronization accuracyVSAvoidsynchronization overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent changes the state parameter of base stations by introducing synchronization levels (first level, second level, third level) to represent different degrees of synchronization accuracy. This parameterization allows the system to track and update only when necessary, reducing overhead while maintaining accuracy where needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where base stations continuously monitor and update their synchronization status and level through the terrestrial interface. This feedback loop allows the system to adapt to dynamic network topology changes while optimizing the frequency and amount of synchronization information exchanged.

Inventive Principle:
Principle #23Feedback

3Loss of information

If air interface resources are used for synchronization, then synchronization information can be acquired, but precious air interface resources are consumed

Engineering Contradiction:
Improvesynchronization information acquisitionVSAvoidair interface resource usage
Core Design Contradiction:
Loss of informationVSLoss of energy

Solution Approach 1:

The patent uses the terrestrial interface as an intermediary channel specifically for synchronization information exchange. This separates the synchronization function from the air interface, allowing synchronization information to be acquired without consuming air interface resources that are needed for user communications.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The terrestrial interface is designed to serve multiple functions: it carries both synchronization status/level information and supports general inter-base station communication. This multi-functionality allows the system to acquire synchronization information efficiently without dedicating separate specialized channels, reducing overall resource consumption.

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

Data Source

PatentEP2498416B1Method and system for synchronizing network nodes in time division duplex system
Publication Date: 2017.11.01 ZTE CORP
  • EP2498416B1 patent drawingFigure 1~2
  • EP2498416B1 patent drawingFigure 3~4
  • EP2498416B1 patent drawingFigure 5~6

AI summary

The disclosure discloses a method for synchronizing network nodes in a time division duplex system. The method includes that: a network node acquires the cell identity information of other network nodes, and inquires the synchronization status information of the other network nodes from a synchronization information node according to the cell identity information; the network node implements synchronization policy according to its own synchronization status and the inquired synchronization status of the other network nodes. A system for synchronizing the network nodes in the time division duplex system is also disclosed, which includes an acquiring unit (60), an inquiring unit (61) and a implementing unit (62). The acquiring unit (60) is used for acquiring the cell identity information of the other network nodes; the inquiring unit (61) is used for inquiring the synchronization information of the other network nodes from the synchronization information node according to the cell identity information acquired by the acquiring unit (60); and the implementing unit (62) is used for implementing the synchronization policy according to the synchronization status of the current network node and the inquired synchronization status of the other network nodes. The method and the system are simple and practical.