WiMAX 망에서 낮은 자원 사용량을 지원하는 QoE 기반의 이동 IPTV 멀티캐스트 시스템

Abstract

In this dissertation, we propose two mobile IPTV multicast systems to improve subscribers' QoE with low resource usage over WiMAX network. Mobile IPTV service needs considerable network resources and strict QoE requirements compared to traditional data services, which is a big burden on wireless networks with very limited resources. Therefore, mobile IPTV multicast system should be designed to efficiently manage resource usage of IPTV channel streams according to the wireless link states of subscribers and to necessarily guarantee subscribers' QoE.First, we present a simple but effective system for the transmission of H.264 MGS coding-based IPTV multicast stream over WiMAX network. The proposed system is implemented to provide more subscribers with an enhanced mobile IPTV service considering their wireless link states. In the proposed system, the base layer of the IPTV channel stream is transmitted with the sparsest modulation scheme and the lowest coding rate to provide IPTV service of minimum quality to as many subscribers as possible. And some parts of the enhancement layer are transmitted with the modulation scheme and the coding rate adaptive to wireless link states of subscribers. Basically, we pursue an efficient tradeoff between the number of subscribers that receive the enhancement layer stream and their IPTV service quality.Second, we present a novel fountain code-based mobile IPTV multicast system over WiMAX network. In the proposed system, the transmission algorithm at a base station determines the control parameters of a fountain-encoded IPTV multicast stream adaptively to the wireless link states of subscribers in order to provide a stable IPTV service with minimum resource usage on WiMAX network, and the channel grouping algorithm at a server makes near-optimal channel grouping based on channel selection preferences to pursue an effective tradeoff between the channel zapping time and the processing complexity of a subscriber.