Synchronization Access Device for Mobile-Ethernet Delay Compensation
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Solution Overview
Problem
The IEEE 802.1AS protocol struggles to maintain precise clock synchronization in industrial factory settings when a mobile network is connected to an Ethernet network, as it fails to account for varying transmission delays in multi-hop device scenarios, leading to inaccuracies in time and frequency synchronization.
Innovation Solution
A synchronization method that involves timestamp information exchange between nodes in both Ethernet and mobile networks, using specific protocol fields to carry timestamp data, allowing for the calculation of round-trip transmission delays and subsequent adjustment to achieve precise time and frequency synchronization, independent of delay variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the IEEE 802.1AS protocol is used for clock synchronization in a mobile network connected to Ethernet network, then the protocol can be applied in industrial factory settings, but the transmission delays in multi-hop devices cause inaccuracies in time and frequency synchronization
Solution Approach 1:
The patent applies preliminary action by having the access device record timestamp information before packet transmission and calculate transmission delays in advance. The access device records the timestamp when the synchronization packet is received from the Ethernet network and when it is transmitted to the terminal device, allowing for pre-calculation of transmission delays that will be used in subsequent synchronization calculations.
Solution Approach 2:
The access device serves as an intermediary between the Ethernet network and the terminal device. It records timestamp information, calculates transmission delays, and adjusts the synchronization packets before forwarding them to the terminal device. This intermediary function allows the terminal device to achieve accurate synchronization despite the multi-hop transmission path through the mobile network.
2Measurement precision
If timestamp information is exchanged between nodes to calculate round-trip transmission delays, then synchronization accuracy is improved, but the complexity of the synchronization process increases
Solution Approach 1:
The access device performs self-service by automatically recording timestamp information and calculating transmission delays without requiring manual intervention or complex configuration from the terminal device. The access device unilaterally records the timestamps, computes the delays, and adjusts the synchronization packets, simplifying the overall process while maintaining high accuracy.
Data Source
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AI summary
A synchronization method and an apparatus are provided to meet a time precision requirement of an industrial factory in a scenario in which a mobile network is connected to an Ethernet network. In the method, a first device determines seventh timestamp information by using timestamp information of receiving and sending packets in a mobile network, so that the second device calculates a time offset between the first device and the second device based on the seventh timestamp information and time points of receiving and sending packets in an Ethernet network, to perform time synchronization. In the method, impact of a transmission delay between the first device and the second device can be avoided, so that a time precision requirement of an industrial factory can be met in a scenario in which the mobile network is connected to the Ethernet network.