1.1System Overview 
      Video on demand is the product of the development of computer technology, network technique and multimedia technology. It is a completely new information service. Video on demand gets rid of the shackles which traditional TV is limited to in time and space. The problem of whatever was wanted and whenever you want to watch is solved. Great’s Video on Demand System (VOD) utilizes the cable TV network, applies multimedia technology to integrate voice, image, graphs, words, data into a whole, playing the leisure-time activities of  audiovisual programs which are designated by particular users. Besides, various kinds of service modes such as payment by times, shuffling, real-time on-demand based on needs are offered.     
      It can be widely used in customer groups such as city communities, hotels, clubs, as well as small and medium-sized enterprises.
1.2System Instruction 
       Business function: high definition video on demand；
       Control functions: fast forward, fast rewind, pause, stop, play, select time, forward step by step, drag to position, etc.； 
       Billing method: Free on Demand(FOD), Staggered Video on Demand(SVOD), True Video on Demand(TVOD)；
      Communication modes: two-way video-on-demand(Cable Modem, IP broadband, EOC), one-way on demand(SMS, telephone, internet)；
      Program format: MPEG1, MPEG2, MPEG4/H.264；
      Network management: SMS system with operators, AMS system network, automatically realized user and resource information management；
      Navigation management: enable operators to customize VOD menu structure and performance effect flexibly;
      Preferential way: discounts, spacialspecial offers, membership cards, consumption points, program package, advertisement click points, etc. 
      Data backup: supporting comprehensive hot-standby; 
      Remote debugging: supporting remote accessing and monitoring of the running state of each server, and can implement remote maintenance; 
      Encrypting transmission: carry out encrypted transmission for user ID, account numbers, passwords and other sensitive data; 
      Statistical statement: make a variety of statisticstatistical analysis and reports for operating income;
      Information query: may check user information from TV at any time;
      Program search: search program by Chinese phonetic alphabet and Chinese input.