Program Multiplexing And Conditional Access Technology Of Digital Television System

As social development and technological progress, the common users are watching the television programs with digital transmission mode. The countries all over the world have proposed the schedule transforming from analogue TV to digital TV. Our government also clearly put forward the realizing of the digital TV by 2015.This thesis studies the Cable Digital TV front end that is suitable for the local market quotation.A typical Cable Digital TV front end should include four parts: Multiplexing and Transmission System of Program Sources and Programs, Electronic Program Guide (EPG), Conditional Access System (CAS), Subscriber Management System (SMS).Sound-vedio coding, based on MEPG-2, is the core of the digital TV technology. DVB real-time encoder is responsible for gathering anolog sound-vedio source and digitizing, then compression coding in MPEG-2. Multiplexing of DVB is divided into program-level and system-level. Program-level Multiplexing refers to those from PES to SPTS while System-level Multiplexing refers to those from SPTS to MSTS.The electronic program guide broadcasting system provides a perfect platform for application of EPG and is responsible for the allocation and coordination of digital TV broadcast network resource and achieves the generating and broadcasting of digital television including the standard table of PSI / SI, the private descriptors and various kinds of application data. Generally speaking, this part of work is completed by a special SI server, and data streams including SI data and programs is on the System-level Multiplexing, then it flows in TS streams.Conditional Access System, which is a comprehensive system, can realize authorization management and control the access of digital television broadcasting. This system involves wide multiple technologies including systems management, network, scrambling and descrambling, encryption and decryption, digital coding and decoding, digital multiplexing, receiving, smart card, and the user management, program management, toll management etc.The CAS and SMS of digital television are inseparable and indispensable. Digital television operation business only can control and manage users precisely through these two systems. It is to say that the SMS is a part of CAS. In CAS, the correlation instruction is sended out from SMS to CA, and the authorized information is producted and transmitted by CA. SMS controls the user through CA, and packs the program according to different combination, generates different products which are also completed through CA by instruction from SMS. SMS, in fact, which is an operation management software platform, provides an integrity, effective management and support. It consists the functions of user management, charging, bookkeeping, customer service, statistical analysis, decision support and customer relations management. It is the essential tool of paying television service and other increment service of the operation business.This thesis introduces the Electronic Program Guide, the principle and application of Conditional Access System, integration of Conditional Access System and Subscriber Management System firstly. The application of this system in Zhangqiu Radio & Television Bureau has been explained emphatically in chapter six.