A Novel Geographic Routing Strategy over VANET 指導教授：許子衡　教授 報告學生：董藝興　學生 作者：Yan-Bo Wang; Tin-Yu Wu; Wei-Tsong Lee; Chih-Heng Ke;  出處：Advanced Information Networking and Applications Workshops (WAINA), 2010 IEEE 24th International Conference on 

Introduction The structure of wireless network can be divided into two modes: Infrastructure Mode and Ad-Hoc Mode. In Infrastructure Mode, there are usually Base Stations (BS) and Access Points (AP) to connect to the large-scale wire network for network communications. 無線網絡的結構可分為兩種模式：基礎模式和Ad - Hoc模式。 在基礎結構模式，通常有基站（BS）和存取點（AP）連接到大型網絡的網絡通信線。

Introduction In no matter MANET or VANET, a mobile node must rely on Ad-hoc routing protocols to determine how to deliver its messages to the destination node. 無論在MANET中或VANET，移動節點必須依靠的Ad - hoc路由協議，以確定如何執行其信息傳遞給目標節點。

Related work

Proposed algorithm A. System Model Assumes that each vehicle is equipped with GPS to obtain the location information of itself. Every vehicle knows its own coordinates. In a fixed beacon interval, each vehicle exchanges the information of the neighbouring vehicles and updates the neighbour list table by beacon messages. RNG and GG graphs are omitted to reduce the calculating time and the complexity of the algorithm. 假定每個車輛配備了GPS獲取位置信息本身。 每部車輛知道自己的坐標。 在一個固定的信標間隔，每輛車的信息交流與鄰近車輛和更新表中的鄰居列表燈塔消息。 RNG和GG被省略，以減少計算時間和複雜度的算法。

Proposed algorithm

Proposed algorithm B. Proposed Algorithm Our proposed algorithm consists of four parts: the purpose of beacon message, the strategy in straight roads, the strategy at the intersections, and the recovery strategy when the algorithm fails. B.擬議的算法 我們所提出的算法包括四個部分：信標消息的目的，在直路的策略，該策略在十字路口，和當算法失敗恢復策略。

Proposed algorithm Beacon Message Each vehicle broadcasts beacon messages periodically to obtain the information of the neighbouring vehicles. Therefore, the beacon message includes the position, velocity and direction acquired from GPS. 廣播信標消息每輛車定期向信標消息獲取信息的鄰近車輛。 因此，從GPS取得信標消息包括位置，速度和方向，。

Proposed algorithm 在圖 6中，有四個鄰國車輛 C的鄰居列表表：車輛的A，B，D和E 此外，車輛比較 A，B和C的鄰居列表表，我們發現，A和B存在車輛的車輛 C的覆蓋面。 但汽車 A和B不顯示在對方的鄰居名單表。 因此，可以推斷，信號被障礙物阻擋或建築物 A和B之間的車輛，車輛 A和B是在不同的道路。 因此，車輛ç即在汽車覆蓋 A和B很可能是在十字路口。 在本文中，我們假設每輛車可以判斷他們是否在十字路口。

Proposed algorithm Straight Road On a straight road, greedy forwarding routing protocol is our chosen strategy. 直路直路，貪婪轉發路由協議是我們選擇的策略。 在貪婪模式，而接收的數據包需要轉發到目的地後，車輛本身的需要為中心的坐標軸，從自身的向量計算到目的地。 接到信號後，有一個協調員進取，貪婪模式將改變在預測模式，這將進一步說明在下一節。

Proposed algorithm Intersection As above mentioned, we assume that a vehicle can judge whether it is the coordinator by beacon messages. When a vehicle broadcasts the signal that it is a coordinator, the neighboring nodes will change to predictive mode to predict the movement of the neighboring nodes. 交叉口上文所述，我們假設一輛車可以判斷它是協調員燈塔消息。 當車輛廣播的信號，表明它是一個協調者，鄰近的節點將改變在預測模式來預測的走勢鄰近的節點。

Proposed algorithm

Proposed algorithm When a vehicle broadcasts the signal that it is a coordinator, the neighboring nodes will change to predictive mode to predict the movement of the neighboring nodes. 當車輛廣播的信號，表明它是一個協調者，鄰近的節點將改變在預測模式來預測的走勢鄰近的節點。 坐標（xn的，yn的）代表第n車輛中的範圍內發現。

Proposed algorithm 例如，在圖 9中的時顯示車輛 S下降到本地最大的，它會變成恢復模式，並使用右手規則，數據包轉發到十字路口。

Simulation scenario

Simulation scenario

Simulation scenario

Simulation scenario