5G Ad Hoc Synchronization Under GNSS Loss and Base Station Outage
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Solution Overview
Problem
5G nodes operating in infrastructureless mode face challenges with timing accuracy and stability due to oscillator drift and interference, especially in environments where commercial GNSS signals are blocked or compromised, leading to communication disruptions and interference among devices.
Innovation Solution
An ad hoc communication network system utilizing ProSe and V2X technologies, combined with nonstandard-GNSS time-synchronization methods and A-PNT systems like MAPS and DAPS, enables devices to maintain synchronization and communication without relying on base stations, using frequency hopping, out-of-band communication, and pre-allocated resources to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If 5G nodes operate in infrastructureless mode using standard oscillators and real-time clocks, then device autonomy and portability are improved, but timing accuracy and synchronization stability deteriorate due to oscillator drift
Solution Approach 1:
The system performs preliminary synchronization by capturing timing information from base station signals before operating in infrastructureless mode. Devices store this pre-acquired timing data and use it as a reference during autonomous operation, allowing them to maintain synchronization without continuous base station contact.
Solution Approach 2:
The patent introduces an intermediary synchronization mechanism where devices exchange timing information with each other through sidelink communications. This peer-to-peer timing exchange acts as an intermediary reference, allowing devices to maintain synchronized operation without relying on external base stations or commercial GNSS systems.
2Adaptability or versatility
If multiple sets of ALEs operate independently after losing base station connectivity, then mission independence and operational flexibility are improved, but interference between different ALE sets increases due to lack of centralized coordination
Solution Approach 1:
The patent merges timing synchronization across multiple independent ALE sets by establishing a common timing reference through sidelink communications. Devices from different ALE sets exchange synchronization signals, allowing them to coordinate their operations and avoid interference while maintaining mission independence.
Solution Approach 2:
The system dynamically adjusts synchronization parameters based on the operational state and connectivity conditions of different ALE sets. When base station connectivity is lost, devices dynamically switch to peer-to-peer synchronization modes, adapting their timing strategies to maintain coordination across independently operating mission groups.
3Measurement precision
If commercial GNSS signals are used for time synchronization, then timing accuracy is improved, but reliability deteriorates in environments where GNSS signals are blocked or compromised
Solution Approach 1:
The patent introduces base station signals as an intermediary timing reference that devices can use instead of commercial GNSS. Base stations provide alternative timing references through cellular signals, allowing devices to maintain synchronization in environments where GNSS is blocked or compromised.
Solution Approach 2:
The system changes the timing reference parameter from commercial GNSS signals to base station signals or peer-to-peer sidelink signals. This parameter substitution allows devices to maintain accurate time synchronization by switching to alternative signal sources that are available in the local environment.
Data Source
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AI summary
A method (400, 5009 and system for operating an ad hoc communication network under suboptimal commercial global navigation satellite system (GNSS) conditions and a loss of a base station communication link is disclosed. The method includes configuring (404, 504) the ad hoc communication network to operation in in-band or out-of-band mode, allowing device-to-device D2D communication. The method further includes configuring the ad hoc communication system to operate in overlay mode, sharing communication resources between network-controlled resources and D2D resources. The method further includes configuring (512) the D2D resources with a base station precedent to the loss of the base station communication link and enabling (516) the ad hoc communication network to operate in frequency hopping mode. The method further includes disabling (520) physical sidelink control channel synchronization and/or resource management within the ad hoc communication network. In some embodiments of the method, and configuring (524) the ad hoc communication network to include at least one nonstandard-GNSS time-synchronization method.