- 學位論文
以IPv6多播功能進行隨按即說服務(PTT)之效能提升手段
Performance Improvement of Push to Talk (PTT) Service with IPv6 Multicast
摘要
隨按即說(Push to Talk, PTT)的技術從早期的無線電對講機(Walkie-Talkies)到 現在常用的手機對講服務(Push to Talk over Cellular, PoC)已有久遠的歷史。最早， 對講機是作為軍事用途，近年來各國則致力於研究關鍵任務一按通服務(Mission Critical Push-to-Talk, MCPTT)，也就是將 PTT 應用於公共安全上，改善第一線人 員使用公共安全通訊系統(Public Safety Communication)的運作效能。由於現今的 PTT 是建立在網路電話(Voice over IP, VoIP)的技術上，所以 PTT 聲音的延遲程度、 多人通話是否造成效能降低以及對行動通訊的支援能力也是大家所關注的。 在本篇論文中，我們設計出在 IPv6 (Internet Protocol Version 6)的環境下，使 用 SIP 協定(Session Initiation Protocol) 以及 TBCP 協定的概念(Talk Burst Control Protocol) 來完成系統中信令(Signaling)控制，並以 GLM (Group List Management) 及 3PCC 協定(Third Party Call Control)完成多播群組(Multicast Group)的建立以及 管理。有別於過往電信業者的 PoC 系統，本篇論文在 IPv6 環境中利用 SIP 代理 伺服器 (Proxy)服務以及 IPV6 多播的方式，讓使用者的聲音串流無須透過伺服 器，也無須複製多份資料給群組內其他使用者，就能達到隨按即說的功能，並 且利用多播方式減少往返伺服器所需傳送的信令。因此提供一個傳輸資料更有 效率，信令交換時間更簡短的即時 PTT 系統。
並列摘要
From the early Walkie-Talkies, to the recent Push to Talk over Cellular (PoC), it has been a long history where the PTT (Push to Talk) technology is applied. Although Walkie-Talkies have been used in military operations in decades, many countries are recently devoted to the Mission Critical Push-to-Talk (MCPTT) technology, which applies PTT to improve the performance of public safety communication for first responders. Because PTT is based on voice over IP (VoIP) technologies, the performance, security, and mobility of PTT are also of great concerns to researchers and manufacturers. This paper proposed a design and implementation of a PTT system, using the SIP (Session Initiation Protocol) and TBCP (Talk Burst Control Protocol) to transport signaling and using GLM (Group List Management) and 3PCC (Third Party Call Control) protocol to create/manage multicast groups. Additionally, in contrast to commercial PoC systems, this paper fully utilizes a subtle design in the SIP protocol and the IPv6 multicast feature, which allows users to send audio data without going through the PTT server, which was the major factor of transmission delay. In summary, this paper provides a more efficient PTT system