車載網路藉由車輛之間的彼此直接連結，取代傳統的實體骨幹網路，並提供額外的傳輸資料來提升道路行駛的安全性。一些相關的服務與標準讓車輛之間可以不用透過一個中央節點的協助，即可彼此互相溝通。相關的研究從早期的行動隨意網路(MANET)開始發展，至今正快速並蓬勃的向前推進，目的在於提供人們更多的功能與安全性選擇。

本篇論文著重於如何改善延遲容忍網絡(Delay Tolerant Networks)的封包傳送率與降低其延遲性。先前曾有Karp學者所提出的GPSR方法，與Zhao學者等所提出的VADD研究，他們針對車載隨意網路環境，提出協助封包繞徑的解決方法。本篇論文進一步嘗試利用「動態地圖密度」，來協助封包傳輸者做出判斷，並成功提高封包的傳輸率。當道路的車輛密度到達一定程度的時候，如果每台車都能擁有即時的地理車輛密度資訊，將十分有助於封包傳輸判斷與傳送。在本篇論文中，將提出一個將上述觀點實作的模型，並透過NS-2與SUMO等實作的方式，模擬本研究的實作結果，並加以探討。

Vehicular networks promise increased road safety while providing additional data transport. This abstract network is an overlay relying on the physical backbone of mobile nodes wirelessly meshed together. The vehicular related services and communication standards enable vehicles to form VANETs in which the vehicles can communicate each other without central access points. Research in this area is maturing rapidly, building upon preliminary work established by MANET research. Benefits of wireless ad hoc networks will provide safety and elective functionalities at far lower cost than current wireless subscriber technologies.

This work is focused on the improvement of packet delivery ratio and delay characteristics for Geographical Routed Delay Tolerant Networks. The pedigree is attributed to Karp's GPSR and Zhao's VADD, which both propose models to represent the vehicular network and then provide a method to perform routing decisions per packet. We follow along the same lines of thought with added emphasis on density to maximize successful transmission opportunities and hence, delivery. When road segments have sufficient vehicle density, the network edge representing the road segment has better capacity to carry information. If network node information is distributed actively over a geographical area, the speed at which packets traverse the wireless mesh would be maximized. This is the heart of this thesis and we provide implementation details and parameters with a discussion as to the benefits of this approach.

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