藍牙(Bluetooth)是為了與攜帶型電子設備(portable electronic devices)傳輸時，取代短距離連接線而發展出來的一個新的通用無線傳輸介面。由於藍牙是通用的傳輸介面，，所以個人區域網路(Wireless Personal Area Network)可以隨時隨地，很容易地建構起來。另外，幾個個人區域網路可能藉由藍牙無線電而形成一個無基地台式的分散式網路(ad hoc network)，繼而導入多點代傳(multi-hop)的通訊傳輸。然而，對於多點代傳的通訊傳輸，在藍牙的規格中並沒有一個明確而具體的方案。而且，在這種無線分散式網路中傳輸多媒體資訊時，所面臨的品質保證(QoS)問題，包含端點到端點間的即時封包延遲，以及端點到端點間的頻寬保留，在藍牙規格上也沒有具體說明。 這篇論文提出了一個以DSDV為基礎的繞路方式，架構在L2CAP層之上來支援資料轉送。在我們提出的系統中，並不需要週期性地廣播來維持繞路表格的一致性。這是由於藍牙的通訊協定提供了連線狀態自動通知的機制，同時，我們又強制繞路的訊息必須在可靠的通道(reliable channel)上傳輸，才得到此效果。利用這樣的方式，就可以提供多點代傳的能力了。在論文中也提出了一個QoS保留(reservation)方法來支援多媒體傳輸，我們稱之為Virtual Link Path (VLP)保留協定。另外，為了增進效率，論文中提出了先測試(pre-probe)輪詢(polling)的排程方法。在模擬實驗中，先測試(pre-probe)輪詢和環式復始(round-robin)輪詢方法做了比較，VLP的保留協定也有進一步的模擬評估。 Bluetooth is a new universal radio interface developed as a short-range cable replacement for linking portable electronic devices. With the “universal” property of Bluetooth, a Wireless Personal Area Network (WPAN) is easily constructed any time any place. Besides, several WPANs may form an ad hoc network via Bluetooth radio and then involve in multi-hop transport. However, there is no specific solution for multi-hop communications in Bluetooth. And further, considering multimedia traffic over such wireless ad hoc network, significant QoS issues including end-to-end real-time packet delay and end-to-end bandwidth reservation are not specified in Bluetooth either. This thesis proposes a routing method based on DSDV to support data forwarding over L2CAP layer. In our system, periodic advertisements are not required to maintain the consistency, since we force routing information to be sent over reliable channel and the Bluetooth protocol provides automatic link status notification. With the basis of this method, the multi-hop transport is available. A QoS reservation method, named as Virtual Link Path (VLP) reservation protocol, is also proposed for multimedia transmission. For improving efficiency, the pre-probe polling schedule is proposed. In the simulation, the pre-probe polling schedule is compared with the round-robin polling schedule, and the VLP reservation protocol is also evaluated.
