Research On Multicast Optimization Of Coaxial-cable IPTV Transmission System

With the fast development of communication and internet technologies, the requirement that people want to get timely information is becoming more and more urgent. At the same time, the traditional passive method to receive information, such as broadcast and TV, cannot satisfy the increasing requirement of interactive communication any more. Just under this background, a new technology called as Internet Protocol TV (IPTV) based on IP networks multimedia services appears. IPTV is defined as an interactive network television, which can provide interactive multimedia services with perfect quality of service (QoS), good user experience, guaranteed security and reliability for consumers.The research work in this thesis is based on the background of the integration of telecommunication networks, cable TV networks and internet networks, which is put forward by State Administration of Radio, Film and Television (SARFT). The IPTV multimedia services in the coaxial transmission network of tri-networks have been studied. Furthermore, the realization processes of multicast technology in the IPTV multimedia services have been researched as an emphasis.At first, the IPTV system architecture and the emerged reason of multicast services are introduced. At the same time, the protocol of internet group management (IGMP) and its’application in the IPTV system are analyzed. Moreover, one of the key parts in the IPTV multimedia services system is the design of multicast scheme in MAC layer, so chapter3focuses on the design strategies of MAC multicast services, meanwhile the scheduling of multicast resource and multicast retransmission approach are also studied in detail.In order to improve the transmission efficiency, the data header compression methods for multicast IP packets are introduced into the IPTV system. In addition, the optimization design of ARQ scheme in the coaxial cable transmission system is developed. For the sake of guaranteeing the transmission quality when IPTV system is undertaking heavy flow and enhancing the QoS guarantee, partial windows multi-refused ARQ mechanism is employed, in which multiple services are distinguished so as to improve system performance.Finally, the performance of multicast scheme is evaluated by using Vxsim of Tornado2.0, the developed testing hardware board based on Cavium5600and personal computer. The network throughput is tested by sending measure data through software of Iperf, the test results demonstrate that the expected purposes are realized.