在車載網路中，因為車輛之間會競爭頻道，導致IEEE 802.11p技術遭受較低的資傳輸吞吐量和系統效率，特別是在交通擁塞的情況下。為了減輕此問題，本論文提出一套應用於車載網路中，結合資料匯集方法的資料傳輸機制。本機制利用一些中繼車輛分散地執行封包合併和分離的方法對抗網路中變動的封包流量，維持傳輸的效率。在效能驗證顯示，相較於原始的IEEE 802.11p機制，此方法基於中繼車輛的資料匯集技術能夠在車輛和基地台之間的通訊，達到較低的碰撞機率、較小的封包重傳次數、較高的資料吞吐量、較高的封包成功率、較高的頻寬使用率和較短的封包延遲時間。 On account of media access competition among vehicles in vehicular ad hoc networks, a vehicular network system based on IEEE 802.11p technologies can still suffer from a serious degradation of transmission throughput and system efficiency, especially when the traffic falls in crowded road conditions. To mitigate this problem, this\vera{thesis}proposes a new data delivery mechanism which incorporates the functionality of data aggregation with conventional vehicular communications. The proposed mechanism can employ some vehicular relays to perform packet fusion and diffusion in a distributed manner to maintain transmission efficiency against varying traffic load in a network. Performance examination shows that as compared with the ordinary IEEE 802.11p scheme, this relay-based data aggregation mechanism is able to achieve a lower collision probability, a smaller number of retransmission times, higher data throughput, higher transmission successful rate, higher throughput utilization, and shorter delay time between vehicle-to-infrastructure communications in vehicular networks.
