| 摘要: | 在現在的社會中，人們對於便利性的需求不斷上升，有線設備礙於繁雜的線路與昂貴的佈線暨維護成本，有線傳輸方式已經不能滿足人們的需求，隨著科技的日新月異，無線通訊已經取代了有線的連接方式。
IEEE 802.11 標準於1997 年被制訂完成，它是IEEE 所提出的第一個無線區域網路標準協定，是一組用來管理無線網路傳輸方法的IEEE 標準，而802.11b 是第一個被廣泛使用的協定，其次是802.11a、802.11g、802.11n 最後是802.11ac。
IEEE 802.11s 標準是IEEE 802.11 針對mesh network 的修訂，它
定義了無線設備可以互相連接並創建一個WLAN mesh network，並且可以用在static topology 以及ad-hoc topology。IEEE 802.11s 擴增了IEEE 802.11 的MAC 標準並且支援broadcast、multicast 以及unicast 傳播，IEEE 802.11s 本身依賴IEEE 802.11a、IEEE 802.11b、IEEE 802.11g 或IEEE 802.11n 任一種模式乘載實際流量，並採用Hybrid Wireless Mesh Protocol (HWMP)作為預設路由協定，但其他的路由協定像是OLSR，B.A.T.M.A.N、AODVUU、DYMOUM 等
這些支援MAC address 的協定也可以使用。
本研究目的是利用OMNeT++ 模擬器模擬Wireless mesh networks (WMNs)，在車載網路環境中分析現有的路由協定以及於不同的traffic type 下效能差異，像是throughput, end-to-end delay, packet delivery ratio。
In recent years, the increasing demand for a more convenient life has led to the development of wireless network technologies. Traditional wireline communication infrastructure suffers from the complexity of both deployment and maintenance, while wireless network technologies can cope with these problems easily.
IEEE 802.11-1997 is the first wireless LAN standard, followed by 802.11b, 802.11a, 802.11g, 802.11n, and 802.11ac. IEEE 802.11s is an IEEE 802.11 amendment for mesh networking that supports unicast, broadcast, and multicast delivery using radio-wave metrics over self-configuring multi-hop topologies. The default routing protocol in IEEE 802.11s is Hybrid Wireless Mesh Protocol (HWMP), however other mesh protocols such as OLSR, B.A.T.M.A.N., AODVUU, DYMOUM are also supported.
In this research, we use OMNeT++ to simulate wireless vehicular mesh networks based on the IEEE 802.11s standard. Then we measure the network performance with the combination of different traffic types and different wireless mesh protocols. The measurement includes packet delivery ratio, end-to-end delay, throughput, and jitter. |
