本文選題：時(shí)鐘同步 + 交換機(jī)�。� 參考：《杭州電子科技大學(xué)》2014年碩士論文

【摘要】：隨著通信網(wǎng)絡(luò)的飛速發(fā)展，移動(dòng)寬帶業(yè)務(wù)的不斷擴(kuò)張，移動(dòng)網(wǎng)絡(luò)全I(xiàn)P化勢(shì)在必行。而在對(duì)分組網(wǎng)絡(luò)建設(shè)時(shí)，一個(gè)關(guān)鍵技術(shù)要求就是要實(shí)現(xiàn)時(shí)鐘同步。在3G無(wú)線通信領(lǐng)域，WCDMA需要支持頻率同步，而TD-SCDMA和CDMA-2000則需要在支持頻率同步的基礎(chǔ)上還需要支持時(shí)間同步。移動(dòng)運(yùn)營(yíng)商在進(jìn)行IP無(wú)線接入網(wǎng)(IP RAN)建設(shè)時(shí)，明確提出了在IP RAN中實(shí)現(xiàn)時(shí)鐘同步，也就是實(shí)現(xiàn)IEEE1588V2的時(shí)間同步協(xié)議。 以太網(wǎng)沒(méi)有提供網(wǎng)絡(luò)時(shí)間同步的能力，對(duì)于時(shí)間敏感的應(yīng)用（如語(yǔ)音視頻，工業(yè)自動(dòng)化）和發(fā)布精確的頻率參考（手機(jī)基站），這樣的功能不能很好地支持。為了達(dá)到時(shí)鐘同步的功能，目前主要是通過(guò)在各基站節(jié)點(diǎn)設(shè)備上安裝GPS(Global Position System)來(lái)獲取精確時(shí)間，使得各接入設(shè)備間實(shí)現(xiàn)時(shí)鐘同步。這種實(shí)現(xiàn)方案系統(tǒng)可靠性低，結(jié)構(gòu)復(fù)雜，施工難度比較大，而且很容易受到干擾等。而在下一代網(wǎng)絡(luò)的核心交換設(shè)備以太網(wǎng)交換機(jī)上實(shí)現(xiàn)IEEE1588V2協(xié)議標(biāo)準(zhǔn)正好解決了該問(wèn)題。“IEEE1588”協(xié)議的全稱是網(wǎng)絡(luò)測(cè)量和控制系統(tǒng)的精確時(shí)鐘同步協(xié)議，通常稱為精密時(shí)間協(xié)議(Precision Time Protocol，PTP)，，該協(xié)議定義了一套精確的時(shí)鐘頻率及絕對(duì)的時(shí)間同步機(jī)制，用于解決成本過(guò)高和精度不足等問(wèn)題。 本文詳細(xì)介紹了IEEE1588V2時(shí)鐘同步標(biāo)準(zhǔn)協(xié)議中定義的PTP時(shí)鐘同步協(xié)議在以太網(wǎng)交換機(jī)中的實(shí)現(xiàn)，并介紹了該協(xié)議的模型及以太網(wǎng)交換機(jī)各功能模塊的實(shí)現(xiàn)，用于替代目前使用高成本的GPS時(shí)鐘同步機(jī)制。此外，還通過(guò)交換機(jī)和測(cè)試儀結(jié)合給出了組網(wǎng)測(cè)試結(jié)果，并做了簡(jiǎn)要分析。最后，本文還指出了該時(shí)鐘同步精度的不足和改進(jìn)方案。
[Abstract]:With the rapid development of communication network and the continuous expansion of mobile broadband services, it is imperative for mobile network IP. In the construction of packet networks, one of the key technical requirements is to achieve clock synchronization. In the 3G wireless communication field, WCDMA needs to support frequency synchronization, while TD-SCDMA and CDMA-2000 need to support time synchronization on the basis of frequency synchronization. In the construction of IP wireless access network (IP ran), mobile operators clearly put forward the implementation of clock synchronization in IP ran, that is, the time synchronization protocol of IEEE 1588V2. Ethernet does not provide the capability of network time synchronization. For time-sensitive applications (such as voice and video, industrial automation) and the release of accurate frequency references (mobile base stations), such functions are not well supported. In order to achieve the function of clock synchronization, at present, it is mainly by installing GPS Global position system on each base station node device to obtain accurate time, so as to realize clock synchronization among access devices. This scheme has the advantages of low reliability, complex structure, difficult construction and easy interference. The implementation of the IEEE 1588V2 protocol standard on the Ethernet switch, the core switching device of the next generation network, solves this problem. The full name of the "IEEE 1588" protocol is the precise clock synchronization protocol of the network measurement and control system. The precision time protocol, commonly known as the Precision time Protocol, defines a set of precise clock frequency and absolute time synchronization mechanisms. This paper introduces the implementation of PTP clock synchronization protocol defined in IEEE 1588V2 clock synchronization protocol in Ethernet switch. This paper also introduces the model of the protocol and the realization of each functional module of Ethernet switch, which is used to replace the current high cost GPS clock synchronization mechanism. In addition, the network test results are given through the combination of the switch and the tester, and a brief analysis is made. Finally, the paper points out the shortcomings of the clock synchronization accuracy and the improvement scheme.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN919.34

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本文編號(hào)：1994714