臺灣博碩士論文加值系統

本論文為達成BLE中公平的週期性傳輸，因此針對Zephyr下BLE的傳輸系統進行解析並改善其效能。在Zephyr提供的系統下，多個Slave對於Master傳輸封包的情境中存在著以下的問題，排程系統的不當安排造成傳輸系統有Idle時間的產生、各個Slave的傳輸順序並無適當的規律、無法控制各Slave存取傳輸通道的時間長度，以上的問題不僅造成系統中的效能浪費，還導致各個Slave所達成的Throughput有明顯的差異，讓Slave之間發生不公平的傳輸現象，因此無法達成公平的週期性傳輸。
而本論文透過傳輸流程的設計，針對Zephyr 提供的BLE系統設計新的排程機制，透過Connection Interval的調整，讓排程機制運作得宜藉此有效的提升整體系統的Throughput。再來讓各Slave的傳輸順序可依使用者設定的順序運行，並且更有效的控制各個Slave傳輸封包的權限，使得Slave存取傳輸通道之時間得到平均的分配。最後是優先權服務的設計，本設計讓使用者決定各個Slave的優先度，並提供週期性傳輸中不同Slave具有不同傳輸順序與封包傳輸量的差別式服務方式。

In order to achieve fair periodic transmission in BLE, this paper analyzes the transmission system of BLE under Zephyr and improves its performance. It is found that a few multiple access problems exist in the Zephyr system when multiple slaves tend to transmit packets to a single master simultaneously. The improper scheduling mechanism causes the idle time. The transmission sequence and the duration for slaves to access the shared communication channel are uncontrollable The above problems may lead to noticeable throughput degradation and unfair access among slaves.
A new scheduling mechanism based upon Zephyr BLE system is provided in this paper. Through the dynamic adjustment of the Connection Interval duration during the transmission process, the scheduling mechanism effectively improve the achieved system throughput. Besides, the transmission sequence and the channel bandwidth allocation of slaves are fully determined according to the user requirement. Therefore, access fairness is achievable in the proposed scheme. This new design is also able to provide differentiated service for various slaves, allowing different slaves to have prioritized transmission orders and transmit different amount of packets in periodic transmission.

摘　要 i
ABSTRACT iii
誌　謝 v
目　錄 vi
表目錄 x
圖目錄 xi
第一章 緒論 1
1.1 研究背景與動機 1
1.2 研究目的 1
第二章 相關技術背景之討論 3
2.1 Bluetooth Low Energy 介紹 3
2.1.1 BLE協定架構 3
2.1.2 裝置之間的連線建立 4
2.1.3 Connection Interval 介紹 6
2.2 實驗環境設置與硬體設備介紹 7
2.3 BLE 5 之PHY mode介紹 7
2.4 Zephyr介紹 8
2.5 Zephyr下之BLE傳輸系統介紹 8
2.6 Zephyr下之BLE傳輸系統的Throughput探討 9
2.7 Zephyr提供的排程機制介紹及問題闡述 10
2.7.1 Connection Event排程時間點 10
2.7.2 各Slave存取傳輸通道時間長度 12
2.7.3 工作排程順序 12
第三章 系統架構設計 13
3.1 Zephyr系統下待解決之問題 13
3.2 系統架構 13
3.2.1 參數介紹 14
3.3 整體系統運作流程 14
3.3.1 Master部分 15
3.3.2 Slave部分 17
3.3.3 整體系統的運作流程 18
3.4 設定Master參數的功能函數介紹 19
3.4.1 set-order Function 20
3.4.2 set-pk-count Function 20
3.4.3 set-period-time Function 20
3.5 排程機制運作比較 20
3.6 與Zephyr提供之系統的傳輸數據比較 22
第四章 系統探討與實驗數據 24
4.1 探討目標以及實驗情境 24
4.2 等待中Slave之CI公式探討 24
4.2.1 等待中Slave之CI實驗 25
4.2.2 等待中Slave之CI公式 27
4.2.3 等待中Slave之CI公式驗證 27
4.2.4 不同情境之數據統整 30
4.3 封包傳輸量公式探討 31
4.3.1 不同Slave連線數、不同週期時間長度之實驗數據 31
4.3.2 公式:封包傳輸量 34
4.4 不同傳輸情況之Maximum Throughput探討 35
4.4.1 Throughput之趨勢解析 35
4.4.2 Maximum Throughput之比較探討 41
4.5 提供不同Slave差別式服務之傳輸實驗 41
第五章 結論 45
5.1 結論 45
5.2 未來目標 45
參考文獻 46

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