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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/32077
標題: | 無線網路上SIP Transaction之研究 A study on SIP Transaction over Wireless Networks |
作者: | Wang-Jui Hsieh 謝旺叡 |
指導教授: | 逄愛君 |
關鍵字: | 無線網路,信令交換,重傳機制, Wireless,SIP,SIP Transaction,Adaptive Retransmission Mechanism, |
出版年 : | 2006 |
學位: | 碩士 |
摘要: | 本論文研究RFC 3261中定義的SIP Transaction在無線網路上會面臨到的問題。SIP Transaction定義了一套重傳機制,當底層缺乏可靠性傳輸時,此機制可以提供User Agent可靠性傳輸。而此機制因為缺乏彈性,導致在無線網路環境中進行SIP信令交換時會因為重傳而缺乏效率。因此本論文提出了一套根據網路狀況動態調整的重傳機制(Adaptive Retransmission Mechanism),以提升SIP信令交換的效率性。 Session Initiation Protocol (SIP) is an application-layer signaling protocol for creating, modifying and terminating multimedia sessions or calls such as voice over IP (VoIP). In SIP, an application-level timeout and retransmission mechanism called SIP Transaction are defined to recover loss/error when unreliable transport is used. Due to the lack of flexibility of the retransmission mechanism, the original design of SIP Transaction results in long call setup delay and additional message transmission overheads for wireless VoIP systems. In this thesis, we develope a two-stage adaptive retransmission mechanism (ARM) to improve the efficiency of SIP Transaction based on the proposed network architecture. An NS2-based simulation model for our ARM is presented. A series of experiments are conducted to investigate the performance of our ARM in terms of average call setup delay, number of retransmissions and power consumption. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/32077 |
全文授權: | 有償授權 |
顯示於系所單位: | 資訊工程學系 |
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