基於WiFi Direct/D2D協定來建構網狀網路

Design of a Wireless Mesh Network System based on Wi-Fi Direct/D2D

黃霈哲(Pei-Che Huang)

指導教授 ： 李皇辰

國立中正大學/工學院/通訊工程學系/碩士(2014年)

摘要

具有對外網路連線能力的智慧型裝置，例如手機與平板電腦等，改變了我們對於網路的應用，例如: 社群通訊軟體(social network)和社交通訊軟體(instant messaging)。使用這些通訊軟體的前提是必須要有網際網路連線，因此衍生以下兩項問題：(1)現場沒有網際網路連線的地方，如郊外、地下室、災難現場等，無法使用。(2)通訊的目標就在隔壁，要彼此通訊時，仍需將所有資料傳遞到基地台再送到網際網路，再轉送到目的地，導致通訊效益低。
使用智慧型手持裝置內建的Wi-Fi Direct/D2D功能，可以讓裝置和裝置之間直接地進行資料交換，無須透過基地台或是特殊通訊設備做為媒介，就可以解決上述兩項問題，並減少網路傳輸的成本，增加網路的使用效率。但是，若是這些通訊裝置散布的區域較大，例如：散佈於一整棟大樓或地下室，則因Wi-Fi Direct的傳輸距離有限，就無法讓這區域內的所有裝置直接進行通訊。
本研究為目前首見於Wi-Fi Direct上實作mesh network的前瞻研究。本研究使用Wi-Fi Direct，並將mesh network區域型網路架構建立在其之上，讓區域內的裝置就算無法以Wi-Fi Direct直接通訊，也可以透過mesh network的拓樸，尋找出目的端到接收端的路徑，並且透過multi-hop方式來達到訊息交換的目的。本研究於Android平台上實作本設計，並且進行通訊性能的測試。結果證實本研究之可行性。

關鍵字

多跳點網狀網路 ； 網狀網路

並列摘要

Smart handheld devices with the Internet connectivity, like smart phone and tablet, brings significant impacts on the way we use networks, such as using social network and instant messaging applications. However, the Internet connection is required when we use these applications and arising the following two problems: (1) It cannot work in the environments without the Internet connection, i.e., remote area, basement and disaster scene. (2) The communication target is nearby, but all the data still require to be transfer to the base station of mobile network, and relay to the Internet, and then send to the target, which causes low network efficiency.
WiFi-Direct/D2D has been adapted in newly introduced devices and enabling devices to exchange data directly without base station support, and therefore, solve the two problems mentioned above. However, its usage is still limited if the distance between devices is exceeded the limitation of Wi-Fi direct or radio signal blocked by in-between obstacles. For example, several smart phones distributed in a building with multiple floors or basement floor cannot communicate to each other by Wi-Fi Direct.
In order to deal with this situation, we present an unprecedented study by building a mesh network topology on Wi-Fi Direct, this helps the devices in the mesh network can send and receive messages based on the known routing paths, and transfer data over a multi-hop Wi-Fi Direct network. This study implements the design on the Android platform, and evaluates the communication performance. The results support the feasibility of the proposed design.

並列關鍵字

Mesh network ； P2P ； D2D ； Wi-Fi P2P ； Wi-Fi Direct ； Wi-Fi D2D ； Multi-hop

參考文獻

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