現今，Wi-Fi Direct技術被廣為運用於實現裝置對裝置通訊。為了減少大量裝置所帶來的網路流量負擔，一個不需要集中式網路設備的裝置對裝置網路被認為是下一世代重要的技術。在緊急狀況發生時，網路拓樸被要求能夠動態並且自動的形成。在這篇文章當中，我們提出一個針對Wi-Fi Direct裝置對裝置網路設計之自律式多重群組建立與通訊機制。我們研讀前人的成果並整理、比較出優缺點，也從中總結出將會面臨的議題。最後，我們成功地解決上述問題並實作於一未修改系統原始碼之Android智慧裝置上。從實驗結果來看，透過語音通話來驗證我們提出的方法是能夠正常運作於一般智慧裝置上。

Nowadays, WFD is widely used to realize D2D communication. To reduce the network traffic loading, a D2D network without infrastructure facilities is required. Due to the emergency scenario like the disaster, network topology has to be established dynamically and automatically. In this paper, we propose an autonomous formation mechanism to form the D2D network with multiple WFD groups and realize the multi-group communication. We have discussed and compared the other previous works to summarize the issues that we will face. Finally, we solved these problems even working in a non-rooted operating system. In the experimental results, our method is validated by a voice communication application on Android device.

1 Introduction ------------------- 1
2 Overview of Wi-Fi Direct ------- 3
3 Literature Review -------------- 5
4 Problem Statement -------------- 8
5 Autonomous Network Formation --- 12
6 Implementation ----------------- 16
7 Numerical Results -------------- 20
8 Conclusion --------------------- 26

[1] Wi-Fi P2P technical specification v1.5. Wi-Fi Allicance, August 2014.
[2] C. Casetti, C. F. Chiasserini, L. C. Pelle, C. D. Valle, Y. Duan, and P. Giaccone. Contentcentric
routing in Wi-Fi Direct multi-group networks. In 2015 IEEE 16th International
Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), pages
1–9, June 2015.
[3] Paul Wong, Vijay Varikota, Duong Nguyen, and Ahmed Abukmail. Automatic Androidbased
wireless mesh networks. Informatica (Slovenia), pages 313–320, 38(4) 2014 (not in
IEEE).
[4] A. A. Shahin and M. Younis. Efficient multi-group formation and communication protocol
for Wi-Fi Direct. In 2015 IEEE 40th Conference on Local Computer Networks (LCN),
pages 233–236, Oct 2015.
[5] Online. Serval mesh documentation. http://developer.servalproject.org/, Oct 2013.