A transmission system asynchronous mapping clock recovery method and device

Abstract

The present invention relates to a transmission system asynchronous mapping clock recovery method and equipment. The method of the present invention includes: receiving customer service and recovering the customer's transmission clock in it to obtain the customer's recovery clock; using the local line side transmission clock to recover the customer's clock Cycle counting to obtain the client clock cycle value in the clock cycle of the line side; insert the client clock cycle value into the overhead of the OTN frame structure, and transmit it to the downstream device. The beneficial effect of the present invention is that since the clock does not need to be extracted from the service data flow, the difficulty of designing a filter circuit to filter out low-frequency interference is avoided, and the resources occupied by the clock recovery circuit are also greatly 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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