时间同步在交换网络中的软硬件方案设计与实现
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摘要
随着通信新技术,新业务,新需求的飞速发展,时间成为判断通信消息是否可靠,可信的重要标志之一。精确的“时间”标志及其在现代交换网络中的作用变得越来越重要。本论文主要研究交换系统中时间同步方案软硬件设计与实现。
本论文的课题直接来源于公司级研发项目。结合本人在项目研发过程中涉及到的硬件电路板IETOD的开发,软件时间同步子系统的研发工作和攻读学位期间收集的时间同步协议研究内容,设计规划适合我国交换系统使用的时间同步网实现方案,从而可以有效的解决电信运营商迫切需要解决的时间不同步造成的各种问题。本论文中所提供的硬件解决方案已经成功的应用于实际工程,为中国网通打造了国内首个时间同步网。
本论文的主要研究内容为:
1.时间同步网相关理论研究。研究重点集中在两个方面:通信系统对时间同步的需求及时间精度的要求和分析研究目前国际上比较通用的时间传送协议和同步协议的工作原理,协议框架。
2.硬件系统设计与实现。基于本人参与设计的硬件电路IETOD及其在北京网通时间同步网建设案例,研究通过硬件系统实现时间同步的几个关键技术点。
3.软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此基础上提出软件解决方案以弥补硬件方案在这些方面的不足。
通过本文的七个章节逐步深入,理论联系实际地阐述了交换系统中时间同步网的相关内容。
第一章首先引出了课题研究的背景,内容。第二章着重解释了时间同步和时间同步网的概念。同时根据现代通信系统中网络架构,业务应用的不同,业务特点阐明了建设时间同步网的必要性。具体研究不同业务对时间同步的精度要求,从而在选择实现方案时可以根据该精度要求选择合适的方式,以较小的投入实现时间同步。第三章和第四章则在理论上详细分析时间同步的原理和技术(主要包括时间同步和时间传送两部分技术),阐述了各个协议的使用场合,进行优缺点比较,为全文提供理论基础。第五章结合本人参与研发的目前交换网络中比较普遍使用的S1240交换机中最新研发成功并使用的时间服务模块(IETOD),详细介绍硬件系统设计与实现。最后通过介绍利用时间服务模块(IETOD)搭建的北京网通时间同步网案例来讨论时间同步网建设中所涉及到的其他设备如传输网,网管系统等的组网关键技术点,给出一个完整的时间同步网硬件实现方案。第六章介绍软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此情况下,我们提出了通过在网管统一平台上内嵌实现同步模块的软件系统方案以弥补硬件系统方案在这一方面的不足。本章将通过介绍本人主要研究的软件同步策略和交换机同步机制来介绍软件方式的系统架构和主要工作原理。第七章全文总结和技术展望。
With the appearance of the new technology, new applications, new requirements, people want to have more saftive, reliable and truthly communication. Time information becomes one of identification to analyse the communication quality. So the applications of time synchronization in communication network become more and more important.“This dissertation focuses on the software and hardware implementation of the time synchronization system for the switching network.
The object of this research is base on one of the company development project, which is applied on site running. Together with my hard work on the key hardware board IETOD during design project process and lots of reference documents and papers about timing protocols and formuls during this paper researching process. In this paper,the theory,character and application sample of different timing protocol was studied and discussed. Finally,time synchronization solution,which applied on the communication network,was given and key technology was analyzed. The given solution can deal with the problem,which caused by the unsynchronization time between the different telecom user or different exchange device. It also can improve the QoS and manage quality of the telecom user. Now the hardware solution is applied on the first time synchronization network in China.
The object of this research is:
1.Research the related theory of time synchronization. Laid a strong emphasis on the research of the communication network requirement to time synchronization; requirement of time precision; study of goble international protocols, including time transmision and time synchronization protocols.
2 . Design and implementation time synchronization by hardware application. Based on the hardware circuit IETOD and application sample on Beijing TELCOM, Research key issues in hardware application.
3 . Design and implementation time synchronization by software application.
There have sevens chapters of this paper.
Chapter 1 gives the decription of this research background and the research object, content etc.
Chapter 2 introduces the ideas of time synchronization and time synchronization network at first. And analyze the different types application,character of different telecom services to make clear the importance of building the time synchronization network.
Chapter 3 and chapter 4 defines the theory and technology of time synchronization (time synchronization technology and time transmission technology),popular time synchronization international protocols. It gives us the theory base to us.
Chapter 5,Using IETOD board,which is an External Time Of Day module used in S1240 exchange, to show a hardware solution. And gives a strong proof to build a time synchronization network,considering the on site running condition.
Chapter 6 shows a softerware solution,which used network manger system.
Chapter 7 gives a conclusion and prospect.
本论文的课题直接来源于公司级研发项目。结合本人在项目研发过程中涉及到的硬件电路板IETOD的开发,软件时间同步子系统的研发工作和攻读学位期间收集的时间同步协议研究内容,设计规划适合我国交换系统使用的时间同步网实现方案,从而可以有效的解决电信运营商迫切需要解决的时间不同步造成的各种问题。本论文中所提供的硬件解决方案已经成功的应用于实际工程,为中国网通打造了国内首个时间同步网。
本论文的主要研究内容为:
1.时间同步网相关理论研究。研究重点集中在两个方面:通信系统对时间同步的需求及时间精度的要求和分析研究目前国际上比较通用的时间传送协议和同步协议的工作原理,协议框架。
2.硬件系统设计与实现。基于本人参与设计的硬件电路IETOD及其在北京网通时间同步网建设案例,研究通过硬件系统实现时间同步的几个关键技术点。
3.软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此基础上提出软件解决方案以弥补硬件方案在这些方面的不足。
通过本文的七个章节逐步深入,理论联系实际地阐述了交换系统中时间同步网的相关内容。
第一章首先引出了课题研究的背景,内容。第二章着重解释了时间同步和时间同步网的概念。同时根据现代通信系统中网络架构,业务应用的不同,业务特点阐明了建设时间同步网的必要性。具体研究不同业务对时间同步的精度要求,从而在选择实现方案时可以根据该精度要求选择合适的方式,以较小的投入实现时间同步。第三章和第四章则在理论上详细分析时间同步的原理和技术(主要包括时间同步和时间传送两部分技术),阐述了各个协议的使用场合,进行优缺点比较,为全文提供理论基础。第五章结合本人参与研发的目前交换网络中比较普遍使用的S1240交换机中最新研发成功并使用的时间服务模块(IETOD),详细介绍硬件系统设计与实现。最后通过介绍利用时间服务模块(IETOD)搭建的北京网通时间同步网案例来讨论时间同步网建设中所涉及到的其他设备如传输网,网管系统等的组网关键技术点,给出一个完整的时间同步网硬件实现方案。第六章介绍软件系统设计与实现。尽管硬件实现具有可靠性高,精度高等优点,但是由于硬件实现方案需要比较大的人力和物力投资用于硬件的改造,周期较长。在此情况下,我们提出了通过在网管统一平台上内嵌实现同步模块的软件系统方案以弥补硬件系统方案在这一方面的不足。本章将通过介绍本人主要研究的软件同步策略和交换机同步机制来介绍软件方式的系统架构和主要工作原理。第七章全文总结和技术展望。
With the appearance of the new technology, new applications, new requirements, people want to have more saftive, reliable and truthly communication. Time information becomes one of identification to analyse the communication quality. So the applications of time synchronization in communication network become more and more important.“This dissertation focuses on the software and hardware implementation of the time synchronization system for the switching network.
The object of this research is base on one of the company development project, which is applied on site running. Together with my hard work on the key hardware board IETOD during design project process and lots of reference documents and papers about timing protocols and formuls during this paper researching process. In this paper,the theory,character and application sample of different timing protocol was studied and discussed. Finally,time synchronization solution,which applied on the communication network,was given and key technology was analyzed. The given solution can deal with the problem,which caused by the unsynchronization time between the different telecom user or different exchange device. It also can improve the QoS and manage quality of the telecom user. Now the hardware solution is applied on the first time synchronization network in China.
The object of this research is:
1.Research the related theory of time synchronization. Laid a strong emphasis on the research of the communication network requirement to time synchronization; requirement of time precision; study of goble international protocols, including time transmision and time synchronization protocols.
2 . Design and implementation time synchronization by hardware application. Based on the hardware circuit IETOD and application sample on Beijing TELCOM, Research key issues in hardware application.
3 . Design and implementation time synchronization by software application.
There have sevens chapters of this paper.
Chapter 1 gives the decription of this research background and the research object, content etc.
Chapter 2 introduces the ideas of time synchronization and time synchronization network at first. And analyze the different types application,character of different telecom services to make clear the importance of building the time synchronization network.
Chapter 3 and chapter 4 defines the theory and technology of time synchronization (time synchronization technology and time transmission technology),popular time synchronization international protocols. It gives us the theory base to us.
Chapter 5,Using IETOD board,which is an External Time Of Day module used in S1240 exchange, to show a hardware solution. And gives a strong proof to build a time synchronization network,considering the on site running condition.
Chapter 6 shows a softerware solution,which used network manger system.
Chapter 7 gives a conclusion and prospect.
引文
[1] Michael Lombardi,Computer Time Synchronization,National Institute of Standards and Technology,Dec. 2000 pp2-5
[2] Hugh Melvin,Liam Murphy, Time Synchronization for VoIP Quality of Service, IEEE Internet Computing, June 2002, pp57-63
[3] Bradley Schatz,George Mohay,Andrew Clark,A correlation method for establishing provenance of timestamps in digital evidence, Digital investigatioin, March 2006, pp98-107
[4] Boyd C,Forster P. Time and data issues in forensic computing case study, Digital Investigation Jan.2004,pp18-23
[5] Mills DL.A brief history of NTP time:confessions of an Internet time keeper,ACM Computer Communication Review,April 2003, pp9-22
[6] General Information on GPS , U.S. Policy Statement Regarding GPS Availability,March 21,2003,pp 142-160
[7] Liu Weifu,Du Chunshang, Studies of Clock Synchronization Network Architecture and Applications in Communication Networks, May 2001, pp21-25
[8] Jeremy Elson,Kay Romer,Wireless Sensor Networks: A New Regime for Time Synchronization, First Workshop on Hot Topics in Networks, Oct. 2002 pp28-29
[9] Jeremy Elson, Deborah Estrin, Time Synchronization for Wireless Sensor Networks,International Parallel and Distributed Processing Symposium (IPDPS), Workshop on Parallel and Distributed Computing Issues in Wireless Networks and Mobile Computing, April 2001,pp30-45
[10] Sivrikaya F,Yener B, Time synchronization in Sensor nerworks:A survery,IEEE Networks,2004,18(4),pp45-50
[11] Alexander Tyrrell, Gunther Auer, Christian Bettstetter, Synchronization Inspired from Nature for Wireless Meshed Networks,In Proc Intern.Conf. on Wireless Communication,Networking and Mobile Computing, September 2006
[12] REN FengYuan,DONG SiYing,HE Tao,LIN Chuang,A Time Synchronization Mechanism and Algorithm Based on Phase Lock Loop,Journal of Software, Feb.2007, pp372-380.
[13] Song Yahui , Li Zaiming,Survey on Time Synchronization in a Local Area Network, Chinese Journal of Scientific Instrument,Dec.2005, pp 33-38
[14] Mills, David L. Computer Network Time Synchronization: the Network Time Protocol, CRC Press, 2006, pp10-20.
[15] J.W. Pan,Present and Future of Synchronization in the US Telephone Network,IEEE Transactions on Ultrasonics,Ferroelectrics and Frequency Control,Vol UFFC-34,No.6,Nov. 1987. pp 629-638
[16] YD/T 1012-1999, Node clock set of digital synchronization network and its timing feature, Jul.1999, pp5-15
[17] Abdi.R. Modarressi, Seshadri Monhan, Control and Management in Next-Generation Networks: Challenges and Opportunities, IEEE Communication Magazine, Oct.2000, pp94-102
[18] David Deeths,Glenn Brunette, Using NTP to Control and Synchronize System Clocks, Sun Blueprints,July 2001 pp4
[19] Mitja.Stular, CDMA As a Universal Multiuser Access Scheme, IEEE MELECON, May, 2002, pp12-15
[20] Leonard Schiff, A.Chockalingam, Design and system operation of Globalstar versus IS-95 CDMA similarities and differences, Wireless Networks,June 2000, pp 47-57
[21] K. Romer, Time and location in sensor networks,GI/ITG Workshop on Sensor Networks, Berlin, Germany,July 2003,pp 57–60.
[22] Athaudage C R N,BER sensitivity of OFDM systems to time synchronization error.The 8th International Conference on Communication Systems( ICCS 2002), 2002, 25-28(1): pp 42-46.
[23] Hou Xiaolin,Yue Guangxin. A comparative analysis on time synchronization schemes in OFDM systems based upon dispersive cannel model. Journal of Beijing University of Posts and Telecommunications, 2003, 26 (3) pp 75-80.
[24] ITU-T Recommendation G.114, One-way transmission time, May. 2000, pp8-10
[25] M. Handley,V. Jacobson RFC2327 SDP: Session Description Protocol ,April 1998,pp9-pp15
[26] Sachin K Agarwal,Avi Yaar,DavidStarobinski,Ari Trachtenberg,Fast Network Synchronization, ACM SIGCOMM Computer Communications Review, Volume 32,Number 3: July 2002
[27] Zhang Dayuan, Realize the Time Synchronization of Communication Network through No. 7 Signaling Network, Modern Science & Technology of Telecommunications,Feb 2006, pp 34-38
[28] David L.Mills ,NTP Precision Time Synchronization ,University of Delaware, Aug 02,2004 ,pp 2-25
[29] David L. Mills ,Network Time Protocol (NTP) General Overview, University of Delaware,Sep.26,2004, pp 2-21
[30] Network Time Protocol (Version 3) Specification,Implementation and Analysis. Network Working Group.RFC1305.,March,1992 pp25-30
[31] Simple Network Time Protocol (SNTP) Version 4,for IPv4,IPv6 and OSI,Network Working Group.RFC2030.,October,1996,pp2-15
[32] Lin Xiliang , Tang Xiaochun,Scheme Designs of the IRIG- B (DC) Level Shift Time Code Transmission over SDH,Radio Engineering of China,Jun 2005 ,pp30-33.
[33] Wei Feng, Lei Zheng,Application of IRIG-B Code in GPS Synchronization Clock Card,Modern Electronics Technique,Mar.2004, pp38-pp42
[34] HE Peng,LI Jing, WU Hai-tao, Research and Implementation of Time Synchronization Wide Area Network, Computer Applications ,Vol 23, No 2 , Feb.2003, pp 15-17.
[35] ZHOU Xian-wei , WEI Wei , QIN Bo-ping,Research on Time Synchronization in Wireless Sensor Network, Chinese Journal of Sensors and Actuators,Jan.2006 ,pp10-13
[36] J. Elson, L. Girod, and D. Estrin, Fine-grained network time synchronization using reference broadcasts, Operating Systems Design and Implementation 2002, Boston, USA, Dec. 2002.pp147-163
[37] David L. Mills,Public Key Cryptography for the Network Time Protocol ,Electrical Engineering DepartmentUniversity of Delaware Technical Report 00-5-1, April 2001,pp2-43
[38] JI Feng,BU Peng, Testing method of time syncheonizaion system, Telecommunication for Electric Power System, July 2003, pp40-41
[2] Hugh Melvin,Liam Murphy, Time Synchronization for VoIP Quality of Service, IEEE Internet Computing, June 2002, pp57-63
[3] Bradley Schatz,George Mohay,Andrew Clark,A correlation method for establishing provenance of timestamps in digital evidence, Digital investigatioin, March 2006, pp98-107
[4] Boyd C,Forster P. Time and data issues in forensic computing case study, Digital Investigation Jan.2004,pp18-23
[5] Mills DL.A brief history of NTP time:confessions of an Internet time keeper,ACM Computer Communication Review,April 2003, pp9-22
[6] General Information on GPS , U.S. Policy Statement Regarding GPS Availability,March 21,2003,pp 142-160
[7] Liu Weifu,Du Chunshang, Studies of Clock Synchronization Network Architecture and Applications in Communication Networks, May 2001, pp21-25
[8] Jeremy Elson,Kay Romer,Wireless Sensor Networks: A New Regime for Time Synchronization, First Workshop on Hot Topics in Networks, Oct. 2002 pp28-29
[9] Jeremy Elson, Deborah Estrin, Time Synchronization for Wireless Sensor Networks,International Parallel and Distributed Processing Symposium (IPDPS), Workshop on Parallel and Distributed Computing Issues in Wireless Networks and Mobile Computing, April 2001,pp30-45
[10] Sivrikaya F,Yener B, Time synchronization in Sensor nerworks:A survery,IEEE Networks,2004,18(4),pp45-50
[11] Alexander Tyrrell, Gunther Auer, Christian Bettstetter, Synchronization Inspired from Nature for Wireless Meshed Networks,In Proc Intern.Conf. on Wireless Communication,Networking and Mobile Computing, September 2006
[12] REN FengYuan,DONG SiYing,HE Tao,LIN Chuang,A Time Synchronization Mechanism and Algorithm Based on Phase Lock Loop,Journal of Software, Feb.2007, pp372-380.
[13] Song Yahui , Li Zaiming,Survey on Time Synchronization in a Local Area Network, Chinese Journal of Scientific Instrument,Dec.2005, pp 33-38
[14] Mills, David L. Computer Network Time Synchronization: the Network Time Protocol, CRC Press, 2006, pp10-20.
[15] J.W. Pan,Present and Future of Synchronization in the US Telephone Network,IEEE Transactions on Ultrasonics,Ferroelectrics and Frequency Control,Vol UFFC-34,No.6,Nov. 1987. pp 629-638
[16] YD/T 1012-1999, Node clock set of digital synchronization network and its timing feature, Jul.1999, pp5-15
[17] Abdi.R. Modarressi, Seshadri Monhan, Control and Management in Next-Generation Networks: Challenges and Opportunities, IEEE Communication Magazine, Oct.2000, pp94-102
[18] David Deeths,Glenn Brunette, Using NTP to Control and Synchronize System Clocks, Sun Blueprints,July 2001 pp4
[19] Mitja.Stular, CDMA As a Universal Multiuser Access Scheme, IEEE MELECON, May, 2002, pp12-15
[20] Leonard Schiff, A.Chockalingam, Design and system operation of Globalstar versus IS-95 CDMA similarities and differences, Wireless Networks,June 2000, pp 47-57
[21] K. Romer, Time and location in sensor networks,GI/ITG Workshop on Sensor Networks, Berlin, Germany,July 2003,pp 57–60.
[22] Athaudage C R N,BER sensitivity of OFDM systems to time synchronization error.The 8th International Conference on Communication Systems( ICCS 2002), 2002, 25-28(1): pp 42-46.
[23] Hou Xiaolin,Yue Guangxin. A comparative analysis on time synchronization schemes in OFDM systems based upon dispersive cannel model. Journal of Beijing University of Posts and Telecommunications, 2003, 26 (3) pp 75-80.
[24] ITU-T Recommendation G.114, One-way transmission time, May. 2000, pp8-10
[25] M. Handley,V. Jacobson RFC2327 SDP: Session Description Protocol ,April 1998,pp9-pp15
[26] Sachin K Agarwal,Avi Yaar,DavidStarobinski,Ari Trachtenberg,Fast Network Synchronization, ACM SIGCOMM Computer Communications Review, Volume 32,Number 3: July 2002
[27] Zhang Dayuan, Realize the Time Synchronization of Communication Network through No. 7 Signaling Network, Modern Science & Technology of Telecommunications,Feb 2006, pp 34-38
[28] David L.Mills ,NTP Precision Time Synchronization ,University of Delaware, Aug 02,2004 ,pp 2-25
[29] David L. Mills ,Network Time Protocol (NTP) General Overview, University of Delaware,Sep.26,2004, pp 2-21
[30] Network Time Protocol (Version 3) Specification,Implementation and Analysis. Network Working Group.RFC1305.,March,1992 pp25-30
[31] Simple Network Time Protocol (SNTP) Version 4,for IPv4,IPv6 and OSI,Network Working Group.RFC2030.,October,1996,pp2-15
[32] Lin Xiliang , Tang Xiaochun,Scheme Designs of the IRIG- B (DC) Level Shift Time Code Transmission over SDH,Radio Engineering of China,Jun 2005 ,pp30-33.
[33] Wei Feng, Lei Zheng,Application of IRIG-B Code in GPS Synchronization Clock Card,Modern Electronics Technique,Mar.2004, pp38-pp42
[34] HE Peng,LI Jing, WU Hai-tao, Research and Implementation of Time Synchronization Wide Area Network, Computer Applications ,Vol 23, No 2 , Feb.2003, pp 15-17.
[35] ZHOU Xian-wei , WEI Wei , QIN Bo-ping,Research on Time Synchronization in Wireless Sensor Network, Chinese Journal of Sensors and Actuators,Jan.2006 ,pp10-13
[36] J. Elson, L. Girod, and D. Estrin, Fine-grained network time synchronization using reference broadcasts, Operating Systems Design and Implementation 2002, Boston, USA, Dec. 2002.pp147-163
[37] David L. Mills,Public Key Cryptography for the Network Time Protocol ,Electrical Engineering DepartmentUniversity of Delaware Technical Report 00-5-1, April 2001,pp2-43
[38] JI Feng,BU Peng, Testing method of time syncheonizaion system, Telecommunication for Electric Power System, July 2003, pp40-41