3gpp accesses

Bước tiến đầu tiên của công nghệ truy nhập vô tuyến WCDMA là đưa ra công nghệ trung nhập gói tốc độ cao đường xuống HSDPA (High Speed Downlink Packet Access) trong phát hành. HSDPA đã mang lại những tiến bộ xa hơn trong việc cung cấp các dịch vụ dữ liệu gói trong WCDMA, cả về mặt hệ thống lẫn hiệu năng người dùng. Việc làm tăng dữ liệu gói đường xuống của HSDPA được hoàn chỉnh bởi những cải tiến đường lên (Enhanced Uplink) được giới thiệu trong phát hành của 3GPP/WCDMA. HSDPA và Enhanced Uplink thường được gọi là HDSA. HSPA+ là tên gọi chung cho những cải tiến của HSPA trong 3GPP phát hành.

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Time Division Multiple Access (TDMA) is the most prevalent wireless access system to date GSM, ANSI-136, EDGE, DECT, PHS, Tetra. Direct Sequence Code Division Multiple Access (DS-CDMA) became commercial only in the mid 90’s IS-95 (A,B, HDR,1x,3x,...), cdma-2000 (3GPP2), W-CDMA (3GPP)

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The terminal performs continuous measurements on its own and neighboring cells and send measurement reports when required. Once the measurement report is sent the serving eNB can take a handover decision and start the handover preparation phase. When the terminal successfully receives the handover command no more communication is required in the source cell T1 is the time from when the handover should occur until it do occur.

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IMS security is divided into access security (specified in 3GPP TS 33.203 [28]) and network security (specified in 3GPP TS 33.210 [29]). Access security (which we describe in Section 12.1) includes authentication of users and the network, and protection of the traffic between the IMS terminal and the network. Network security (which we describe in Section 12.2) deals with traffic protection between network nodes, which may belong to the same or to different operators.

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3GPP, or the Third Generation Partnership Project, was formed in late 1998 to specify the evolution of GSM into a third generation cellular system. Although much focus was placed on new higher bandwidth radio access methods, it was realized that the network infrastructure must also evolve in order to provide the rich services capable of taking advantage of higher bandwidths. The original GSM network infrastructure was very much circuit- and voicecentric. Although data capabilities were added over time the system retained much of its circuit-switched heritage and its inherent limitations.

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