Clock Correlation in Transparent Transmission Networks
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Solution Overview
Problem
Current synchronization technologies in Optical Transport Networks (OTNs) lead to low bandwidth utilization and high costs due to complex phase-locked loops used for clock recovery, resulting in fragile performance.
Innovation Solution
The implementation of two phase-locked loops, one at the transmitter and one at the receiver, to correlate and de-correlate clocks transparently, allowing separate data transmission from the clock in Ethernet networks, thereby enhancing bandwidth utilization and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GFP-T encapsulation method is used to encapsulate all data including IDLE, then the receiver can receive all transmitter data, but the bandwidth utilization is low and bandwidth is wasted
Solution Approach 1:
The patent extracts the clock signal from the data stream and transmits it separately through a dedicated clock channel. This separation allows the data channel to transmit only actual data without IDLE frames, significantly improving bandwidth utilization while the clock channel ensures timing information is preserved for reliable data reception
Solution Approach 2:
The patent divides the transmission system into two independent channels: a data channel for carrying user data and a clock channel for carrying timing information. This segmentation allows each channel to be optimized independently - the data channel achieves high bandwidth utilization while the clock channel ensures reliable data reception through dedicated clock signal transmission
2Measurement precision
If phase-locked loop is used to recover clock from data rate, then clock recovery is achieved, but the technology becomes complicated, cost increases and performance becomes fragile
Solution Approach 1:
The patent introduces a dedicated clock channel as an intermediary to transmit timing information directly from the transmitter to the receiver. This eliminates the need for complex phase-locked loops to extract clock signals from data streams, simplifying the receiver architecture while maintaining accurate clock recovery through the dedicated clock signal
Solution Approach 2:
The patent creates a separate clock signal copy that is transmitted independently through the clock channel. This copied clock signal arrives at the receiver already synchronized and ready for use, eliminating the need for complex clock recovery processes and reducing both hardware complexity and performance fragility
Data Source
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AI summary
A communication system, communication method, transmitting apparatus, and receiving apparatus are disclosed herein. The communication system includes: a first clock correlating unit, adapted to correlate a clock to be transmitted with a clock of a data frame at a transmitter of a clock transparent-transmission network; and a second clock correlating unit, adapted to correlate a clock of a data frame at a receiver of a clock transparent-transmission network with a clock to be recovered. The method includes: correlating the clock to be transmitted with the clock of the data frame at the transmitter of the clock transparent-transmission network, and correlating the clock of the data frame at the receiver of the clock transparent-transmission network with the clock to be recovered.