Ethernet Clock Selection for Upstream Timing Continuity
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Solution Overview
Problem
Edge devices in optical transport networks cannot continue transmitting the clock of an upstream device through non-flexible Ethernet interfaces due to reliance on local crystal oscillators, limiting the precision of the sending clock.
Innovation Solution
The method determines a clock for non-flexible Ethernet interfaces using signals received by the network device, allowing the use of an upstream device's clock as the sending clock, enhancing precision by selecting the highest quality or priority physical layer clock based on received signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple downlink clocks are used for time synchronization in a small cell network, then time synchronization accuracy is improved, but clock determination complexity increases
Solution Approach 1:
The patent implements a feedback mechanism where the second eNodeB measures timing difference information from downlink signals received from the first eNodeB, then feeds back this measurement result to the first eNodeB. This feedback loop enables automatic clock determination and adjustment, improving time synchronization accuracy while reducing manual configuration complexity through self-optimizing algorithms that automatically select the best downlink clock sources.
Solution Approach 2:
The system enables self-service through automatic clock determination where the network elements autonomously perform clock source selection and timing adjustment without manual intervention. The second eNodeB automatically measures timing differences, identifies optimal downlink clocks, and adjusts its timing accordingly, allowing the network to self-optimize synchronization performance while reducing operational complexity.
2Ease of manufacture
If timing advance values are adjusted in coarse granularity, then implementation simplicity is improved, but time synchronization precision deteriorates
Solution Approach 1:
The timing advance adjustment is segmented into multiple granularity levels. Coarse-grained adjustments are used for initial timing alignment and large deviations, while fine-grained adjustments are applied for precise timing optimization. This segmentation allows the system to achieve high precision through fine adjustments without sacrificing implementation simplicity, as the coarse adjustments handle the bulk of timing corrections efficiently.
Solution Approach 2:
The system dynamically adapts the granularity of timing advance adjustments based on operational conditions. During initial synchronization or when large timing deviations occur, coarse-grained adjustments are used for simplicity. When approaching optimal timing, the system transitions to fine-grained adjustments to achieve precise synchronization, thus dynamically optimizing both implementation simplicity and precision based on the current synchronization state.
Data Source
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AI summary
This application discloses a method and an apparatus for determining a clock, and a storage medium, and pertains to the field of communication. The method includes: A first network device receives a first signal and at least one second signal, where the first signal carries data to be sent through a first flexible Ethernet interface; determines a first physical layer clock based on the first signal; determines a second physical layer clock based on the at least one second signal or the first physical layer clock and the at least one second signal; and uses the first physical layer clock or the second physical layer clock as a sending clock of a non-flexible Ethernet interface. The first network device includes the first flexible Ethernet interface and the non-flexible Ethernet interface. In this application, a network device can continue transmitting a clock of an upstream device through a non-flexible Ethernet interface.