Research And Implementation On Unicast-based Iptv Fast Channel Change System

Because of its interactive enhancement,Internet Protocol Television (IPTV) service can increase the ARPU value and it is more successful to retain customers, which will help communications and media service providers get new profit growth. But the IPTV channel switch with a long time delay greatly reduces the degree of user experience. This paper presents a solution by adding a cache server in the network which is aid to provide fast channel change and retranssmission, using a combination of unicast and broadcast application, it can not only consider the bandwidth constraints, but also maximize the efficiency of channel switching that less than one second can be achieved.This paper makes an overview of the structure of existing IPTV networks,including the network architecture and components, introduces the communication protocols involved, and describes the key technologies of IPTV. After researching on the statistical data about the existing channel switching time,get the three main factors which effect channel switching delay, including the delay on leaving or joining muticast, waiting for key information and the delay on client cache, in which the most important one is the delay to wait for critical information.This paper introduces several fast channel change solutions and analyzes their advantages and disadvantages, and makes this proposal at last. The network structure of the program is described in detail, including the various components and functions. This proposal uses the special protocols which is made for fast channel switching using unicast-based communication, on which the data packet structure is discussed.Based on the linux platform this paper implements the fast channel change system including the client and server side, of which the design of each part was explained, the system workflow is also described. Using Network Damage Meter this paper sets up a network to simulate the reality of IPTV network environment, on which the client and caching server are tested. At last the high efficiency of this fast channel change system is proved,with recording and analysis of the channel switching time.