Transmission system asynchronous mapping clock recovery method and transmission system asynchronous mapping clock recovery device

Abstract

The invention relates to a transmission system asynchronous mapping clock recovery method and a transmission system asynchronous mapping clock recovery device. The transmission system asynchronous mapping clock recovery method includes receiving a client service and carrying out a recovery process to a client sending clock in the client service to obtain a client recovered clock; using a sending clock of a local line side for counting cycles of the client recovered clock to obtain a client clock cycle value in a clock cycle of the line side; and inserting the client clock cycle value into an overhead of an open transport network (OTN) frame structure to pass the client clock cycle value to a downstream device. The transmission system asynchronous mapping clock recovery method and the transmission system asynchronous mapping clock recovery device have the advantages that since the clocks do not need to be extracted from service data flow, the difficulty of designing a filter circuit to remove low-frequency interference through filtration is eliminated, and at the same time, resources occupied by a clock recovery circuit are substantially reduced.

Description

technical field [0001] The invention relates to the field of communication transmission systems, in particular to a clock recovery method and equipment for asynchronous mapping in an optical transport network. Background technique [0002] With the continuous development of communication technology, OTN has gradually become the mainstream of transmission network, especially the development of OTN-based cross-scheduling technology, which makes OTN gradually develop into a multi-service bearer platform. Many services require transparent transmission of service clocks. [0003] Some services adopt the method of synchronous mapping, that is, the service clock is used to encapsulate the service data flow on the OTN network. This application requires a fixed frequency ratio between the access service and the OTN service, and cannot realize the transparent transmission of multi-channel customer service clocks. [0004] When customer services are transmitted through the OTN networ...

AI Technical Summary

Problems solved by technology

This method is difficult to filter out the low-frequency jitter introduced during the mapping and demapping process, and the drift index is difficult to pass

[0009] However, in the face of the transparent transmission requirements of synchronous Ethernet and wireless services, the quality of the clock recovered by using the two-level cache method cannot meet the requirements, and it is difficult to filter out the low-frequency interference introduced during the mapping and demapping process, and the jitter and drift indicators are very low. Difficult to satisfy

If the method of introducing the clock board is adopted, the hardware needs to be redesigned, and many devices on the network need to be updated, which is unacceptable in terms of cost

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