Kiến trúc hệ thống và biểu Tổng mô tả các mạng GSM được cấu trúc hệ thống dọc (Hình ). Họ đáng kể của khu vực hành chính bao gồm ít nhất một, mà là giao cho một Trung tâm Chuyển mạch di động (MSC). Mỗi khu vực hành chính được tạo thành ít nhất một Địa điểm Diện tích (LA). Đôi khi LA cũng được gọi là khu vực truy cập. LA An bao gồm các nhóm tế bào khác nhau. Mỗi nhóm tế bào được phân công một Base Station Controller (BSC). Vì vậy đối với từng LA tồn. | GSM Switching Services and Protocols . Second Edition. Jörg Eberspächer Hans-Jörg Vögel and Christian Bettstetter Copyright 2001 John Wiley Sons Ltd Print ISBN 0-471-49903-X Online ISBN 0-470-84174-5 3 System Architecture and Addressing General Description GSM networks are structured hierarchically Figure . They substantially consist of at least one administrative region which is assigned to a Mobile Switching Center MSC . Each administrative region is made up of at least one Location Area LA . Sometimes the LA is also called the visited area. An LA consists of several cell groups. Each cell group is assigned to a Base Station Controller BSC . Therefore for each LA there exists at least one BSC but cells of one BSC may belong to different LAs. Figure GSM system hierarchy The exact partitioning of the service area into cells and their organization or administration with regard to LAs BSCs and MSCs is however not Linic Lic 1 y determined and is left to the respective network operator who thus has many possibilities for optimization. Figure shows the system architecture of a GSM Public Land Mobile Network PLMN with essential components. The hierarchical construction of the GSM infrastructure becomes evident again. The cell is formed by the radio area coverage of a Base Transceiver Station BTS . Several base stations together are controlled by one BSC. The combined traffic of the mobile stations in their respective cells is routed through a switch the Mobile Switching Center MSC . Calls originating from or terminating in the fixed network . the Integrated Services Digital Network ISDN 7f are handled by a dedicated Gateway 30 3 System Architecture and Addressing MS Mobile Station BTS Base Transceiver Station HLR Home Location Register BSC Base Station Controller VLR Visited Location Register MSC Mobile Switching Center EIR Equipment Identity Register GMSC Gateway MSC AUC Authentication Center ISC International Switching Center OMC Operation and .
