跳到主要內容

臺灣博碩士論文加值系統

(35.153.100.128) 您好!臺灣時間:2022/01/19 02:32
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

: 
twitterline
研究生:施江霖
研究生(外文):Jiang-Lin Shi
論文名稱:新式的電信網路主參考信號源
論文名稱(外文):New Approaches to Primary Reference Source in Telecommunications Networks
指導教授:賀嘉律
指導教授(外文):Chia-Li Ho
學位類別:博士
校院名稱:國立中央大學
系所名稱:電機工程研究所
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2002
畢業學年度:90
語文別:英文
論文頁數:87
中文關鍵詞:(無)
外文關鍵詞:PRSGPSNFSSONETSDH
相關次數:
  • 被引用被引用:0
  • 點閱點閱:267
  • 評分評分:
  • 下載下載:30
  • 收藏至我的研究室書目清單書目收藏:1
論文名稱﹕新式的電信網路主參考信號源 頁數:87
校所組別﹕國立中央大學 電機工程研究所 通訊組
畢業時間及提要別﹕九十學年度 第二學期 博士學位論文提要
研究生﹕施江霖 指導教授﹕賀嘉律教授
論文提要內容﹕
由於高速網路時代的來臨,今日電信網路對於高準確度的主參考信號源(PRS)的要求比以往更為殷切。在第三章完成一個藉由GPS共同觀測技術同步於國家標準頻率系統的主參考信號源,這是一項非常強而有力的時間與頻率傳送方式。依據ITU-T G.811規定,一個電信主參考信號源的頻率準確度必需優於1×10-11,在這種狀況下,對於64 kbit/s的通路,70天不能大於一個信號滑失(slip)。但為達到相同的滑失率,高速網路其準確度必定少於1×10-13,例如SDH或SONET。這對於現存的大部分網路架構是無法符合的。本文所完成的電信主參考信號源追溯國家頻率標準,準確度達到5×10-14以上。本系統是以低成本,其性能追溯國家頻率標準為5×10-14。而這頻率性能顯示,電信主參考源的頻率偏移優於5×10-14 ±1×10-14,而在這種情形下,幾乎沒有犧牲到頻率穩定度。
第四章,提出利用光纖系統傳送時間及頻率。這系統利用SONET/SDH的 overhead比次(bytes)框架來傳送定時信號。這系統在溫度控制下利用折返(loop back)方式完成測試。試驗結果顯示不管使用5米或35公里長的光纖,其短期時間穩定度達到5 ps,長期頻率穩定度優於1×10-14。而且在35公里的折返實驗,其遲延變化少於1.4 ns。
在這篇論文,提出一個電信主參考源以較便宜的價錢同步到國家標準頻率的高準確度,以大幅提升電信網路性能;同時利用光纖電纜傳送高準確度的時間及頻率,以提供高速網路的需求。以上兩項均得到非常良好的結果。

ABSTRACT
With the introduction of high-speed networks, today’s telecommunications networks require a more accurate primary reference source (PRS) than conventional ones. A PRS synchronized to the national frequency standard (NFS) based on the technique of global positioning system (GPS) common view, a powerful means for time and frequency transfer, is proposed in chapter 3. According to ITU-T G.811 [2], the frequency accuracy of a PRS should be better than . At this order, the network is allowed to have not greater than one slip in 70 days for any 64 kbit/s channel. To achieve the same slip rate, the accuracy should be less than for a high-speed network such as synchronous digital network (SONET) or synchronous digital hierarchy (SDH). This is not achievable for most existing schemes [3], [4]. The proposed PRS achieves performance comparable to the NFS, which is at present accurate to better than . Our method achieves performance comparable to the NFS, which has frequency accuracy of the order up to , with a lower cost. Performance results indicate that the frequency offset of the PRS is improved to almost without sacrificing the stability. Indicate that a PRS with frequency offset can be improved to .
An optical system for time and frequency transfer via optical fibers, presented in chapter 4. The system used a number of unused overhead bytes of the SONET/SDH frame, in transmitting a timing signal. The system completed the loop-back test in temperature-controlled conditions. Experimental results showed that short-term time stability can be achieved at 5 ps, and long-term frequency stability is better than , regardless of whether the loop-back is a 5 meter or 35 km long optical fiber. Moreover, the delay variation in the 35 km loop-back test was less than 1.4 ns.
In this dissertation, a PRS synchronized to the NFS with high performance and lower cost, used optical fiber to transmitted high precise time and frequency are proposed. All got good results.

New Approaches to Primary Reference Source in
Telecommunications Networks
Chapter 1 Introduction
1.1 Motivations
1.2 Fundamental Concepts of Time and Frequency
1.2.1 Background and Definitions
1.2.2 First Definition of the Measure of Frequency Stability─
Frequency Domain
1.2.3 Second Definition of the Measure of Frequency Stability─
Time Domain
1.2.4 Translation between the Spectral Density of Frequency
and the Allan Variance
1.3 Structure of This Dissertation
Chapter2 Overview of Telecommunication Synchronization
Networks
2.1 Requirements for Primary Reference Source
2.1.1 Background
2.1.2 Impact of Slips on Services
2.1.3 SONET and SDH Synchronization Needs
2.1.4 Error Bursts Caused by Lost of Synchronization
2.1.5 Synchronization Performance Objectives─Public Network
2.1.6 Synchronization Performance Objectives─Private Network
2.2 Telecommunications Synchronization Architecture
2.2.1 Major Method for Synchronization
2.2.2 Telecommunication Synchronization
2.3 Characteristics of Synchronization Networks
( performance and quality of clocks)
2.3.1 Source Clocks: Primary Reference Source
2.3.2 Receiver Clocks
2.3.3 Clock Standards
2.4 Synchronization Performance and Planning
2.4.1 Synchronization Performance
2.4.2 Synchronization Planning
2.5 Summary
Chapter 3 A New Method for Improving Primary Reference
Source
3.1 Introduction
3.2 Fundamental of GPS
3.2.1 GPS outline
3.2.2 GPS Time
3.2.3 GPS Time Receivers
3.2.4 GPS Time Transfers
3.3 GPS Common View Based PRS
3.4 System Controller
3.5 Implementation and Results
3.6 Summary
Chapter 4 Application to Two-Way Time and Frequency Transfer
using SONET/SDH
4.1 Introduction
4.2 Preliminary
4.3 The System Architecture and Testing Method
4.3.1 The Transceiver
4.3.2 The Control Circuit
4.3.3 The Timing Circuit
4.4 Experiment Results
4.5 Summary
Chapter 5 Conclusions and Prospective
Bibliography
[1] D.W. Allan and M.A. Weiss, “Accurate time and frequency transfer during common view of a GPS satellite,” in Proc. 34th Ann. Symposium on Frequency Control, pp. 334-346, May 1980.
[2] “Timing requirements at the output of primary reference clocks suitable for plesiochronous operation of international digital links,” ITU-T Recommendation G.811.
[3] J.E. Abate, et al, “AT&T’s new approach to the synchronization of telecommunication networks,” IEEE Communications Magazine, vol. 27, no. 4, pp. 35-45, April 1989.
[4] W. Lewandowski, J. Azoubib, and W.J. Klepczynski, “GPS: primary tool for time transfer,” Proc. of the IEEE, vol. 87, no.1, pp. 163-172, Jan. 1999.
[5] M.A. Lombardi, Tutorial on frequency calibrations and time transfer, NIST Time and Frequency Division.
[6] J. Rutman and F.L. Walls, “Characterization of frequency stability in precision frequency sources,” Proc. of the IEEE, vol. 79, no. 6, pp. 952-960, June 1991.
[7] Samuel R. Stein, Frequency and Time─Their Measurement and Characterization, NIST, Characterization of Clocks and Oscillators, pp TN-61, March, 1990.
[8] James A. Barnes, Andrew R. Chi, Characterization of Frequency Stability, NIST, Characterization of Clocks and Oscillators, pp. TN-146, March, 1990.
[9] Study Programme, Characterization of frequency and phase noise, NIST, Characterization of Clocks and Oscillators, pp. TN-162, March, 1990.
[10] J.J. Spilker, Jr., “GPS signal structure and performance characteristics,” Navigation, vol. 25, no. 2, pp.121-122, Summer 1978.
[11] R.J. Miliken and C.J. Zoller, “Principle of operation of NAVSTAR and System Characteristics,” Navigation, vol. 25. no. 2, p.121. Summer 1978.
[12] N Ashby and D.W. Allan, “Practical implications of relativity for a global coordinate time scale,” Radio Science, vol. 14, no. 4, pp. 649-669, 1979.
[13] Wlodzimierz Lewandowski and Claudine Thomas, “GPS Time Transfer,” Proc. 34th Annual Symp. On Frequency Control, pp.334-346, May 1980.
[14] P.F. MacDoran, “Satellite emission radio inerferometric earth surveying, SERIES─GPS geodetic system,” Bull. Geodesique, 1979.
[15] AT&T, “Effects of Synchronization Slips,” ITU-T Contribution COM SpD-TD, NO.32, Geneva, November, 1969.
[16] J. E. Abate, and H. Drucker, “The Effect of Slips on Facsimile Transmission,” IEEE International Conference on Communications, pp. 1022-1025, 1988.
[17] H. Drucker, and A.C. Morton, “The Effect of Slips on Data Modems,” IEEE International Conference on Communications CH2424-0/87/0000-0409 1987.
[18] J. E. Abate, et al, “AT&T’s New Approach to the Synchronization of Telecommunication Networks,” IEEE Communications Magazine, Vol. 27, No. 4, April 1989.
[19] K. Inagaki, et al, “International Connection of Plesiochronous Networks Via TDMA Satellite Link,” International Conference on Communications 1982, IEEE, 0536-1486/82/0000-02221.
[20] M. Decina and Umberto de Julio, “Performance of Integrated Digital Networks: International Standards,” IEEE International Conference on Communications 0536-1486/82/0000-0063 1982.
[21]“Synchronization Interface Standards for Digital Networks,” American National Standard for Telecommunications, ANSI T1.101, 1994.
[22] “The Control of Jitter and Wander Within Syncronization Networks,” European Telecommunication Standards, Draft ETS DE/TM-3017.
[23] “The control of jitter and wander within digital networks which are based on the 1544 kbit/s hierarchies,” ITU-T Recommendation G.824, 1987
[24] “Standard Clock Testing Methodology,” ITU-T COM XVIII D.1378, 1987.
[25] D.W. Allan, clocks and oscillators, “Time and frequency (time-domain) characterization, estimation, and prediction of precision,” IEEE trans. On Ultrasonics, Ferroelectrics, and Frequency Control, vol. UFFC-34, no. 6, pp. 647-654, Nov. 1987.
[26] J.A. Barnes, “The measurement of linear frequency drift in oscillators,” Proc. 15th Annual PTTI Meeting, pp. 551-579, 1983.
[27] J.A. Davis and J.M. Furlong, “Report on the study to determine the suitability of GPS disciplined oscillators as time and frequency standards traceable to the UK national time scale UTC(NPL),” Center for Time Metrology, National Physical Laboratory, NPL Report no. CTM-1, Oct. 1997.
[28] C. Hackman, S.R. Jefferts, and T.E. Parker, “Common-clock two-way satellite time transfer experiments,” Proc. 49th Annual Symp. Frequency Control, pp. 275-281, 1995.
[29] S.R. Jefferts, M.A. Weiss, J. Levine, S. Dilla, E.W. Bell, and T.E. Parker, “Two-way time and frequency transfer using optical fibers,” IEEE Tran. Instrumentation and Measurement, 46(2), pp.209-211, Apr. 1997.
[30] D.W. Allan, “Time and frequency (time-domain) characterization, estimation, and prediction of precision clocks and oscillators,” IEEE Trans. Ultrasonics, Ferroelectrics, and Frequency Control, 34(6), pp.647-654, Nov. 1987.
[31] “General requirements for the competence of testing and calibration laboratories,” ISO/IEC 17025, 1999.
[32] L.S. Cutler and C.L. Searle, “Some aspects of the theory and measurement of frequency fluctuations in frequency standards,” Proceedings of the IEEE, 54(2), pp.136-154, Feb. 1966.
[33] P. Lesage and C. Audoin, “Characterization and measurement of time and frequency stability,” Radio Science, 14(4), pp. 521-539, 1979.
[34] P. Lesage and T. Ayi, “Characterization of frequency stability: analysis of the modified Allan variance and properties of its estimate,” IEEE Trans. Instrumentation and Measurements, 33(4), pp. 332-336, Dec. 1984.
[35] “Selection and use of precise frequency and time systems,” International Telecommunication Union, Handbook, 1997.
[36] M. J. Klein and R. Urbansky, “Network synchronization ─ A challenge for SDH/SONET?,” IEEE Commun. Mag., pp.42-50, 1993.
[37] J. C. Bellamy, “Digital network synchronization,” IEEE Commun. Mag., Vol. 33, pp.70-83, 1995.
[38] “Digital hierarchy bit rates,” ITU-T Rec. G.702, 1988.
[39] “Synchronous digital hierarchy bit rates,” ITU-T Rec. G.707, 1993.
[40] R. F. Bridge, S. Bily, J. Klass, and R. Taylor, “Jitter attenuation in T1 networks,” IEEE ICC’90, pp. 685-689, 1990.
[41] H. Sari and G. Karam, “Cancellation of pointer adjustment jitter in SDH networks,” IEEE Trans. Commun. Vol. 42, No. 12, pp.3200-3207 , 1994.
[42] “The control of jitter and wander within digital networks which are based on the 2048 k bit/s hierarchy,” ITU-T Rec. G.823, 1993.
[43] M. Kihara and A. Imaoka, “SDH-based time and frequency transfer system,” Proc. of the ninth European and Time Forum, pp. 317-322, 1995.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top