3GPP定義IP多媒體多媒體子系統為3G移動系統的核心網路,也提出IP多媒體多媒體子系統會在下一代網路中扮演重要的角色,在封包交換中支援多媒體服務。在使用IP多媒體多媒體子系統服務前,使用者必須先取得無線網路的使用權限然後再向IP多媒體多媒體子系統的核心網路做註冊。我們在無線網路中的認證伺服器內使用快取機制,並在 IP 多媒體子系統核心網路中管理使用者資訊的伺服器內存放接取網路的認證資訊,提出一個新的冊機制做到快速認證,並減少IP多媒體多媒體子系統核心網路內的訊息交換和註冊時間。然後我們使用交大網路模擬器,模擬提出的註冊機制和標準註冊流程,並比較兩方所費時的註冊時間。模擬結果指出我們提出新的註冊機制相對於標準註冊流程在延遲上有較好的表現。
The IP Multimedia Subsystem (IMS) is originally defined as the core network for 3G mobile systems by the 3rd Generation Partnership Project (3GPP), and has been proposed as a key element in Next Generation Networks (NGN) that supports multimedia services in the packet switched domain. Before using IMS services, users should first obtain access to radio networks and then register to IMS core network. We propose an improved registration mechanism to reduce the number of message exchange in IMS core network and latency. The mechanism caches and stores access authentication information separately in the AAA server in access network and in the HSS. We compare registration latency of our proposed mechanism with the standard through NCTUns simulator. The simulation results confirm better performance of our proposed mechanism.