可追溯標準時間源系統是透過階層式的架構，將國家標準時間延伸到一般應用伺服器。本系統共分為三層，第一層為標準時間伺服器，其時間源與國家標準時頻實驗室維護的國家標準時間同步，第二層為次級時間源伺服器，其伺服器與標準時間伺服器必須透過適當管控的校時程序來同步時間，第三層為時間相關的應用伺服器，提供時間服務時，必須向上層次級時間源伺服器請求標準時間。週期性的校正、完整的校時記錄、完整的量測監控校時程序中的校時誤差、公正地稽核程序是建立系統可追溯性的充分條件，在有可比對的完整記錄與準確的量測結果為依據下，系統提供可信賴且可追溯的標準時間，提供電子商務、電子政府應用中必備的。本論文最主要貢獻有兩部分，第一運用雙向傳時的技術降低雙向傳時時間校正的誤差，其二是設計校時誤差量測的實驗來建立時間源的可追溯性。

In this thesis, we present a hierarchical and traceable standard time source system which distributes the national standard time to arbitrary application servers. The system consists of three layers, the first layer is the NMI server, which maintains a the time source synchronized with the national standard time, the second layer is the TC server, which synchronizes its time source with the NMI server through the modem/telephone link, and the third layer is the application server, which requests standard time from a TC server.
Traceability of this system is established through periodical time synchronizations, the integrity of the records of time synchronization, error measurements of time synchronization, capability of maintaining stable frequency source, and fair auditing processes. The main contribution of this thesis are two folds; first use two-way time-transfer technique over modem/telephone links is used to reduce errors of time synchronization, and the second consists of experiments which measure time synchronization errors to establish the traceability of the distributed time source.

第一章、 簡介
1.1 背景與動機..............................................1
1.2 主要方法和貢獻..........................................3
1.3 相關機制回顧............................................4
1.3.1 代理簽章機制........................................4
1.3.2 線性鏈結機制........................................5
1.3.3 向傳時機制..........................................6
第二章、 可追溯標準時間源架構
2.1 階層式標準時間源架構.....................................7
2.2 NMI伺服器..............................................9
2.3 TC伺服器..............................................10
2.4 應用伺服器.............................................11
2.5 可追溯標準時間源........................................11
2.5.1 可追溯性的定義.....................................11
2.5.2 稽核..............................................13
第三章、 系統時作
3.1 時間校正程序...........................................14
3.1.1 時間校正的基本程序..................................14
3.1.2 強化的時間校正程序..................................16
3.1.3 逐步修改TC伺服器時間程序............................19
3.2 授權書和金鑰實作........................................20
3.2.1 授權書內容與金鑰需求................................20
3.2.2 授權書內容與金鑰實作................................22
3.3 記錄檔的時做與保護機制..................................24
3.3.1 線性鏈結機制.......................................25
3.3.2 記錄檔的格式.......................................26
第四章、 單向傳時的校時誤差量測
4.1 非同步序列通訊埠傳輸延遲量測實驗..........................27
4.1.1 實驗目的...........................................27
4.1.2 實驗環境設定.......................................30
4.1.3 實驗方法...........................................31
4.1.4 實驗結果...........................................32
4.2 單向傳時之校時誤差量測實驗...............................34
4.2.1實驗目的............................................34
4.2.2 實驗方法...........................................35
4.2.2.1 實驗環境設定...................................38
4.2.2.2 數據機參數設定.................................39
4.2.3 實驗結果.............................................45
第五章、 雙向校時的校時誤差量測
5.1 設計目的...............................................50
5.2 雙向傳時時間校正方法....................................50
5.3 校時誤差實驗...........................................56
5.3.1 校時訊號傳遞路徑設定................................56
5.3.2 數據機參數設定.....................................56
5.4 實驗結果..............................................56
第六章、 結論..............................................59
參考文獻...................................................60
附錄A ....................................................62
附錄B.....................................................68

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