藍芽是一種短距離無線通訊網路的前瞻性技術，主要是用來取代有線的設備。在藍芽技術的規格中，只定義了如何建立一個互相連接的網路，稱為Piconet。因此，在文獻上已經有一些方法被提出來，探討如何將數個Piconets連接成更大的Scatternet網路。此建構Scatternet的過程稱為Scatternet formation。我們稱樹狀結構的Scatternet為Bluetree，這種結構有三個缺點：第一、資料繞送的效能不佳。Bluetree若非平衡樹而是歪斜樹將造成嚴重的繞送路徑問題。第二、在Bluetree中父節點極易形成通訊的瓶頸。第三、缺乏可靠性。當父節點因為關機或是離開通訊範圍時，Bluetree將會造成幾個不連接的子樹。
在這篇論文中，我們提出了一個階層式建構Bluetree的方法，將藍芽裝置一層一層地加入Bluetree中。這種階層式長成之的Bluetree架構解決了傳統Bluetree的缺點，它讓Bluetree一直保持在平衡樹的狀態，使得繞送路徑可以維持較短的距離，同時在兄弟節點之間建立了連線，以提供額外的繞送路徑。如此一來，不但父節點的流量瓶頸問題可以大大改善，而且當一個父節點斷裂後只會造成兩個分裂的部份，而可以得到較佳的可靠度。

Bluetooth is a promising technology for short-range wireless communication and networking, mainly used as a replacement for connected cables. Since the Bluetooth specification only defines how to build a Piconet, several solutions have been proposed to construct a Scatternet from the Piconets in the literatures. The process of constructing a Scatternet is called the Scatternet formation. We find that a tree shape Scatternet, called Bluetree, has three defects: First, it lacks efficiency in routing because the Bluetree may form a skewed tree instead of a balanced tree, resulting in serious longer routing path. Second, the parent nodes in Bluetree are very likely to become the bottlenecks of communication. Third, it is not reliable. When a parent node is lost, several separate subtrees will be caused.
In this thesis, we present a method that generates the Bluetree hierarchically; that is, the nodes are added into the Bluetree level by level. This hierarchical grown bluetree (HGB) topology resolves the defects of conventional Bluetree. During growing up, HGB always remains balanced so as to preserve shorter routing paths. Besides, the connections between the siblings provide alternative paths for routing. As a result, the traffic load at parent nodes can be greatly improved and only two separate parts will be induced if a parent node is lost. Better reliability is therefore achieved.

中文摘要…………………………………………………………………I
英文摘要…………………………………………………………………III
目錄………………………………………………………………………V
圖目錄……………………………………………………………………VI
表格目錄…………………………………………………………………VII
第一章 簡介……………………………………………………………1
第二章 相關研究………………………………………………………14
第三章 階層式長成藍芽樹……………………………………………19
第3.1節 階層式長成藍芽樹建構方法…………………………………21
第3.2節 階層式長成藍芽樹繞送方法…………………………………31
第四章 實驗結果………………………………………………………38
第4.1節 ARP評估………………………………………………………40
第4.2節 DDR評估………………………………………………………42
第4.3節 Throughput評估………………………………………………43
第五章 結論……………………………………………………………48
參考文獻…………………………………………………………………50

[1]Bluetooth Core Specification, http://www.bluetooth.com
[2]BluetoothTM 1.1: Connect Without Cables by Jennifer Bray and Charles F. Sturman.
[3]Jaap Haartsen, Mahmoud Naghshineh, Jon Inouye, Olaf J. Joeresson, and Warren Allen, “Bluetooth: Vision, Goals, and Architecture,” ACM Mobile Computing and Communications Review, Volume 2, Number 4, October 1998, pp. 38-45. Invited paper.
[4]Theodoros Salonidis, Pravin Bhagwat, Leandros Tassiulas, Richard LaMaire, “Distributed Topology Construction of Bluetooth Personal Area Networks,” IEEE INFOCOM 2001, Anchorage, Alaska, April 2001.
[5]G.V. Zaruba, S. Basagni, I. Chlamtac, “Bluetrees - Scatternet formation to enable Bluetooth-based ad hoc networks,” IEEE International Conference on Communications (ICC) 2001, pp. 273-277.
[6]Godfrey Tan, Allen Miu, John Guttag and Hari Balakrishnan, “Forming Scatternets from Bluetooth Personal Area Networks,” MIT Technical Report, MIT-LCS-TR-826, October 2001.
[7]Ching Law and Kai-Yeung Siu, “A Bluetooth Scatternet formation algorithm,” Proceedings of the IEEE Symposium on Ad Hoc Wireless Networks 2001, San Antonio, Texas, USA, November 2001.
[8]Z. Wang, R.J. Thomas, and Z.J. Haas, “Bluenet - a New Scatternet Formation Scheme,” 35th Hawaii International Conference on System Science (HICSS-35), Big Island, Hawaii, January 7-10, 2002.
[9]S. Basagni, C. Petrioli, “A Scatternet Formation Protocol for Ad Hoc Networks of Bluetooth Devices,” IEEE Vehicular Technology Conference Spring 2002, Vol. 1, pp 424-428.
[10]M. Sun, C.K. Chang and T.H. Lai, “A Self-Routing Topology for Bluetooth Scatternets,” Proc. I-SPAN 2002, Manila, Philippines, May 2002.
[11]C.C. Foo, K.C. Chua, “BlueRings - Bluetooth Scatternets with Ring Structures,” IASTED International Conference on Wireless and Optical Communication (WOC 2002), Banff, Canada, July 2002.
[12]P. Bhagwat, A. Segall, “A routing vector method (RVM) for routing in bluetooth Scatternets,” Proc. IEEE International Workshop MoMuC, pp. 375-379. Nov. 1999.
[13]ns-Network Simulator: http://www.isi.edu/nsnam/ns/
[14]ns manual: http://www.isi.edu/nsnam/ns/ns-documentation.html
[15]C. Lee and A. Helal, “An ns-based Bluetooth LAP Simulator,” Proceedings of the 26th Annual IEEE Conference on Local Computer Networks (LCN), November 14, 2001, Tampa, Florida