The Subway CCTV system comprises two levels: one for platforms, subway trains, parking lots and the other for control center. Besides, the CCTV system for subway police consists of three levels including platforms, subway trains, parking lots, subordinate police service centers and superior police service center.
Structured by end-to-end NGN, the system realizes the following functions: optimized network flow by real-time video stream multicasting with no repeated occupying of bandwidth when recalled by many users; enhanced emergency respond speed by direct-to-IPSAN storage with no file packaging, the reliability is higher with fast searching within a second and immediate playback; N + M storage backup structure for specialized CCTV foreign domains’ backup with high performance-price ratio; dual-streams direct storage for Public Security Department with two backup streams for important surveillance sites.
