Method, device and system for clock synchronization

Abstract

The invention discloses a method, device and system for clock synchronization. According to the method for clock synchronization, after a triggering controller in a secondary IWF device receives a master clock pulse count value sent by a primary IWF device, if the primary clock pulse count value is judged as the first primary clock pulse count value received by the secondary IWF device, the triggering controller indicates a secondary pulse counter to count output clock signals of a voltage-controlled oscillator with the primary clock pulse count value as an initial value, otherwise, the triggering controller indicates a numeric comparator to load the primary clock pulse count value and the secondary clock pulse count values, the numeric comparator generates a control signal according to the difference values of the primary clock pulse count value and the secondary clock pulse count values, and the output clock frequency of the voltage-controlled oscillator is adjusted. Due to the fact that the clock frequency of the secondary IWF device follows the clock frequency of the primary IWF device all the time, the transmission quality of TDM data can be maintained at the normal level through the shaking and drifting indexes of clock recovering.

Description

technical field [0001] The present invention relates to the communication field, in particular to a method, device and system for clock synchronization. Background technique [0002] The circuit switching network based on TDM (Time Division Multiplexing) adopts connection-oriented technology, has low delay and delay jitter, and can provide user services with guaranteed bandwidth and excellent QoS (Quality of Service, service Quality) performance, which can provide high-quality transmission services for real-time services such as voice, enterprise private line, and multimedia data. For a long time, traditional telecom operators have adopted circuit switching technology to widely deploy fixed PSTN (Public Switched Telephone Network, Public Switched Telephone Network) and mobile communication networks. However, the circuit switching network also has limitations such as low bandwidth utilization and limited switching capacity, which cannot meet the growing demand for data servi...

AI Technical Summary

Problems solved by technology

These characteristics affect the jitter and wander specifications of the recovered clock according to the adaptive clock recovery algorithm

[0012] In the actual application of circuit emulation, TDM devices interconnected through PSN, such as mobile base stations and enterprise leased line access client devices, are placed in complex geographical locations and far away from the operator's central office, so it is difficult to implement circuit emulation devices. Both ends obtain a common external synchronous clock source, and it is difficult to recover an accurate and stable synchronous clock by using an adaptive clock recovery method

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