Based On The Ethernet Switch IEEE1588V2Research And Implementation Of Clock Synchronization Protocol

With the rapid development of communication network, the services of mobile broadband areexpanding continually, mobile network with IP technology will be imperative. In the packetnetwork construction, a key technology requirement is to achieve clock synchronization. In the fieldof3G wireless communication, WCDMA needs to support the frequency synchronization, whileTD-SCDMA and CDMA-2000needs in support of time synchronization based on the need tosupport frequency synchronization. Mobile operators in the IP radio access network (IP RAN)construction, clearly put forward the implementation of clock synchronization in IP RAN, which isthe realization of IEEE1588V2time synchronization protocol.Ethernet does not have the ability to provide network time synchronization, for time sensitiveapplications (such as voice and video, industrial automation) and the function of releasing accuratefrequency reference (mobile phone base station) which can not support well. In order to achieve thefunction of clock synchronization, at present mainly through the installation of the GPS in the basestation node device (Global Position System) to obtain the exact time, in order to achieve the clocksynchronization between access devices. This implementation scheme of system reliability is low,the structure is complex, the difficulty of construction is relatively large, and very susceptible to beinterfered. At the core switching equipment of the next generation network, Ethernet switchboardrealizes the IEEE1588V2protocol standard just solve the problem."IEEE1588" protocol is the full name of the protocol of network measurement and theprecision clock synchronization of control system,usually called the precision time protocol(Precision Time Protocol, PTP), the protocol defines a set of precised clock frequency and absolutetime synchronization mechanism, solves the problems of high cost and the lack of precision etc.This paper detailed introduces the PTP protocol and defined in IEEE1588V2clocksynchronization standard protocol is implemented in Ethernet switch, and introduces model of theprotocol and the realization of all function modules of the Ethernet switch, for replacing the highcost of the currently used GPS clock synchronization mechanism. In addition, also has gave thenetwork test results through the switch and the tester, and a brief analysis.Finally, this paper alsopoints out the deficiencies of the clock synchronization accuracy and improvement scheme.