這篇論文主要的目的是實作一個應用在數位家庭中的多聲道數位無線喇叭。傳統家庭中都是用有線的方式來連接家電，例如電視、錄放影機…等，但有線的缺點是昂貴、佈線複雜以及容易造成危險。所以使用IEEE802.11無線通訊協定來取代傳統的有線系統。經過調查顯示，聆聽動聽的音樂是每個家庭中最普遍的娛樂且也是每個房間都不能缺少的服務。實作多聲道數位無線喇叭放置在每一個房間，使用者可以透過網頁選擇想聽的歌曲，然後由家中的多媒體伺服器以串流技術的方式傳送至無線喇叭播出。為了讓使用者能享受環繞音效，採用分散的無線喇叭設計，每一個聲道都是獨立的。所以在此情況下，必須去考慮每個聲道是不是可以同步的播出聲音。無線網路的時間同步有很多議題被提出來討論，同時也有很多時間同步的演算法被提出來。我們在實作中結合NTP和RBS演算法的優點，讓數位無線喇叭達成同步，並且解決軟體同步以及封包遺失的機制。

In this paper, we propose a multi-channel digital wireless speaker system for our digital home. Cabling systems have been a source of annoyance to users due to some drawbacks such as expensive cost, complexity, dirtiness and danger. In our system, we use IEEE802.11 wireless network instead of traditional cable system. Through our survey, we know the service of audio needed in each room in family. We place our wireless speaker in each room; users can connect to streaming media server through web page and select song which want to listen. To let user can enjoy sound surround, we adopt distributed wireless speaker. So under the cooperative relation environment, we must synchronize each member of this wireless speaker. Time synchronization is an important issue in wireless network; it aims to provide a common timescale for local clocks of nodes in the network. In this paper, we implement an algorithm to combine the advantage of Network Time Protocol (NTP) and Reference Broadcast Synchronization (RBS) algorithm, and use the streaming technology of Real Time Protocol (RTP). We resolve these problems: time synchronization, software synchronization and resend the lost packets in our experiment.

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