TDM-based network clock recovery system

Abstract

The invention relates to the field of network communications, in particular to a TDM-based network clock recovery system. The system comprises a data clock dividing module, a data caching module, a clock recovery module and a parallel-to-serial processing module; the data clock dividing module is connected with the data caching module and the clock recovery module; the data caching module and the clock recovery module are connected with the parallel-to-serial processing module. The TDM-based network clock recovery system adopts data ranking and clock recovery division processing, and the processing speed is higher; data ranking adopts the method that data are directly stored at corresponding positions according to serial numbers, the ranking efficiency is higher, and the functions of lost packet and invalid packet processing and counting are achieved; meanwhile, data clock self-adaptive recovery is achieved by the adoption of the sampling and counting mode for the data serial numbers, the needed time for recovery is short, and the recovery precision is high; in the process of adjusting a clock, the discrete pulse insertion mode is adopted, so that the clock is adjusted more stably, the clock pulse jitter is small, and the 2.048MHz clock recovery precision realized by the adoption of the system reaches up to 10 ppb, and the requirement for the network data receiving and sending synchronization is better met.

Description

technical field [0001] The invention relates to the field of network communication, in particular to a TDM-based network clock recovery system. Background technique [0002] like figure 1 As shown, CES (Circuit Emulation Service) circuit emulation provides a smooth transition solution from the circuit switching network to the packet switching network. The PE device at the sending end encapsulates the TDM data in real time, and transmits the TDM data to the receiving end through the packet network. At the receiving end, the PE The data buffer queue at the receiving end of the device recovers the synchronous clock, and the synchronous clock decapsulates the data frame and reassembles it into a TDM data stream; however, because the TDM network is a synchronous network, and the packet network is a typical asynchronous network, TDM data is transmitted through the packet network to At the receiving end, it will cause its own clock information to be lost. Therefore, the clock reco...

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Problems solved by technology

[0002] such as As shown in Figure 1, CES (Circuit Emulation Service) circuit emulation provides a smooth transition solution from the circuit switching network to the packet switching network. The PE device at the sending end encapsulates the TDM data in real time, and transmits it to the receiver through the packet network. At the receiving end, the data buffer queue of the PE device at the receiving end restores the synchronous clock, and the synchronous clock decapsulates the data frame and reassembles it into a TDM data stream; but because the TDM network is a synchronous network, the packet network is a typical asynchronous network, and the TDM data It will cause the loss of its own clock information when it is transmitted to the receiving end through the packet network. Therefore, the clock recovery technology is very important when recovering TDM data at the receiving end. The recovery of data clock information directly affects the quality of data transmission. The current clock recovery technology There are problems such as long recovery time and poor recovery accuracy

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