tailieunhanh - IP-Based Next-Generation Wireless Networks phần 7

Trường này được dành riêng để sử dụng trong tương lai và phải được thiết lập là 0 bởi người gửi và phải được bỏ qua tiếp nhận. . Nhà cung cấp / Org-ID: Trường này chứa các định danh của các nhà cung cấp hoặc tổ chức đang sử dụng phần mở rộng này. . | 240 MOBILITY MANAGEMENT receives from the PS CN domain the user data destined to the mobile and then distributes the data inside the RAN to the mobile. In order for a mobile to exchange signaling messages with the PS CN . to set up and manage the traffic bearers to perform location update a dedicated logical signaling connection needs to be established between the mobile and the SGSN. Recall that this signaling connection consists of a signaling Radio Bearer and an Iu Signaling Bearer. A mobile does not have to maintain all the traffic bearers in the RAN or the CN if it does not expect to send or receive user data soon. The mobile does not even need to maintain its dedicated signaling connection to the SGSN at all times. Releasing the radio resources that a mobile is unlikely to need soon allows these radio resources to be used by other mobiles and helps conserve the scarce power resources on the mobile. Which network connections bearers that make up the host-specific route between a mobile and its serving GGSN need to be changed when the mobile moves around depend on the scope of mobility. Figure illustrates the different scopes of mobility and which parts of the host-specific route between a mobile and its serving GGSN may be affected in each mobility scope. Inter-Node B Handoff Handoff from one Node B called the source Node B to another Node B called the target Node B requires that the mobile s Radio Bearers to be changed from the source Node B to the target Node B. Inter-RNC Handoff With an inter-RNC handoff a mobile moves its radio bearers from one RNC called the source RNC to another RNC called the Fig. Scope of mobility in 3GPP packet-switched domain MOBILITY MANAGEMENT IN 3GPP PACKET NETWORKS 241 target RNC . Therefore if the target RNC also becomes the mobile s serving RNC after the handoff . in a hard inter-RNC handoff the mobile s Iu Bearers also need to be changed in addition to the changes of the Radio Bearers. Inter-SGSN Handoff .