在本論文中，我們提出一個CBT (Cluster-based TDMA)的機制，作為行動車輛在Intra-cluster與Inter-cluster的通訊方式，此機制可以解決車載式網路 (VANET)在同時傳輸封包時會產生碰撞的問題。在Intra-cluster的部分，我們藉由隨機選取0或1的方式來選出VC (VANET Coordinator)，在VC選出之後，VNs使用隨機的方式選取不同的time slot來提出BR (Bandwidth Requests)，如果有兩個以上的VN選擇同一個time slot提出BR，則會發生碰撞，發生碰撞的VNs繼續在下一個TDMA frame提出BR直到成功。在VC根據BR完成排程之後，所有的VN就可以使用指定的time slots來傳送data。在Inter-cluster的部分，當兩個Clusters互相接近時，VCs為了重新排程，必須互相交換彼此的SAM (Slot Allocation MAP)，我們採用的方式是VCs藉由隨機選取0或1的方式來決定是否傳出SAM，等到某一VC已經先成功傳出SAM，則另一VC根據收到的SAM來重新安排time slots。
在Intra-cluster的部分，我們求出選出VC需要的平均time slot數、所有VNs提出BR需要的平均time slot數，在Inter-cluster的部分，我們求出成功傳出SAM的平均time slot數、兩個VCs廣播出SAM所需要的time slot數。除此之外，我們還求出傳送data前平均需要等待的time slot數。我們撰寫C++模擬程式來驗證推導的數學公式是否正確，經由比較數學分析與模擬的結果，我們發現兩者在提出BR的部分有較大的差距，其原因在於使用數學分析時，我們無法知道VNs是選擇哪幾個time slots來提出BR，其他部分的數學分析都與模擬結果接近。

In this Thesis, we propose a Cluster-based TDMA (CBT) scheme for Vehicular Ad-hoc Networks (VANET). In the CBT, the collision problems can be solved when packets are transmitted at the same time.
In the Intra-cluster communications, the VANET Coordinator (VC) is determined by randomly choosing a number of zero or one. Other VANET Nodes (VNs) then randomly select different time slots to transmit their Bandwidth Requests (BRs). If more than two VNs choose the same slots for BRs, collision will occur. The failed VNs will continue to issue BRs in the next TDMA frames. After the time slots are scheduled by VC, all VNs can use the designated time slots to send data. In the Inter-cluster communications, when two clusters are approaching to each other, two VCs must exchange Slot Allocation MAP (SAM) using the random zero-or-one scheme. The VCs successfully receive SAM must reschedule the time slots.
For the purpose of performance evaluation, we calculate the average time slots of selecting VC and the average time slots required for successful BRs. We also compute the average time slots required for successfully transmitting SAM and the average time slots required for broadcasting SAM to all VNs. Finally, we calculate the average time slots required for waiting before data transmission. To validate the mathematical results, we perform a simulation written in C++. When comparing the mathematical results to the simulation results, we observe that in the average time slots required for BR, the former is larger than the latter. This is because in the mathematical equations it is difficult to specify which time slots are used by VNs to transmit BRs. However, the rest of performance comparisons, the two results are very close.

目錄
第一章 導論 1
1.1 研究動機 1
1.2 研究方法 2
1.3 章節介紹 4
第二章 車載式通訊網路 5
2.1 V2V與V2R 6
2.2 IEEE 802.11p 6
2.3 TDMA 7
2.4 Cluster 8
2.5 VANET MAC的相關研究 9
2.5.1 VANET MAC 9
第三章 Cluster-Based TDMA 15
3.1 Intra-Cluster/Inter-Cluster的基礎架構 15
3.2 TDMA Frame與MAC Frame Format 16
3.2.1 TDMA Frame的設計 17
3.2.2 MAC Frame Format 18
3.3 CBT的演算法 21
3.3.1 Intra-Cluster 21
3.3.2 Inter-Cluster 26
第四章 數學分析與模擬結果 31
4.1數學分析模式的建立 31
4.1.1 Intra-cluster的數學分析 32
4.1.2 Inter-cluster的數學分析 36
4.2數學分析與模擬驗證 38
4.2.1 Intra-cluster 38
4.2.2 Inter-cluster 42
第五章 結論與未來工作 43
5.1 結論 43
5.2 未來工作 44
參考文獻 (REFERENCES) 46
ACRONYMS 51
索引 (INDEX) 52

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