1、基於車間 Geocast 之一種具穩定性通訊拓撲之適應性路由控制機制設計Adaptive Routing Control Mechanism with Provision of StableCommunication Topology Based on Inter-Vehicle Geocast郭茂源 Kuo, Mao-Yuan指導教授：龔旭陽 Kung, Hsu-Yang 【摘要】隨著車載資通訊產業的興起，在車用行動通訊網路(Vehicular Ad-hoc Network)的環境下已有許多研究進行探討，由於其環境下容易因節點具高速移動之特性的情況下常常受到無線傳輸距離範圍有限及節點移動性導
2、致容易造成多變的網路拓撲之情況。本論文設計車間通訊架構之基於車間 Geocast 之一種具穩定性通訊拓撲之適應性路由控制機制設計(Adaptive Routing Control Mechanism with Provision of Stable Communication Topology Based on Inter-Vehicle Geocast, ARSC)主要以專用短距通訊(Dedicated Short Range Communication, DSRC)設備於車間通訊中複雜的車間通訊網路環境中進行網路拓樸的尋找，以地域性群播之概念於特定地理區域內限制車隊探索訊息的散播區域範圍找
3、尋目的地車輛，且考慮行駛中車間之行駛資訊及地理位置資訊尋找具穩定性車隊車間通訊路由拓撲，根據車輛行駛資訊評估分析以調適傳輸路由策略，提供車間通訊適應性拓撲控制方法。最後，本論文透過專用距離通訊設備 IWCU 進行車間通訊之建立與訊息分享，並藉由交通模擬系統 Vissim 結合交通部國道高速公路局提供之實際高速公路交通資訊數據來模擬真實高速公路上常見之各種交通車流量、車輛密度及各種車流量下之平均速度情形來驗證此機制的效能，由模擬及分析結果我們能證明此機制的準確性與可行性，透過本機制設計以更精確的預測模型來預測車輛行駛之行 為，並同時提升整體路由連結時間。相信此路由探索機制能為車用行動通訊網路上的
4、車間通訊服務提供新的方向及做法。關鍵字：車用行動通訊網路、車間通訊、地域性群播、適應性路由調適【Abstract 】In recent year, Vehicular Ad-Hoc Networks (VANETs) are an emerging Telematics environment. With the use of Global Positioning System, geocast allows to efficiently limit the message dissemination to geocast region. We utilized the inter-vehic
5、le geocast which consists informing the fleet of highway about any information such as driving or danger information. This work proposes a communication control mechanism achieve the stable inter-vehicle connection, which is based on Geocast. The operation principle of inter-vehicle geocast is that
6、the information sharing among vehicles is defined by the information in the specific geographical region. Within the specific geocast region the stable inter-vehicle communication is provided based on the highway conditions and vehicle statuses, including the vehicle speed, transmission distance and
7、 location information on the road of the specific region. The key idea of the proposed adaptive routing algorithm is the adaptive defer time routing which is used to construct the route connection of the fleet and to predict the connection life time which the new relay vehicles are also be identifie
8、d before network disconnection occurs. Finally, we use Vissim to simulate the real vehicle mobility in highway. The results show that ARSC is longest life time method for highway and reduces the route number of disconnection. The proposed adaptive routing scheme achieves the stable inter-vehicle communication and dynamic information sharing under the normal or jam traffic situations.Keywords：VANETs, Inter-Vehicle Communication, Geocast, Adaptive Routing
