Scalable Video-on-demand Streaming For Heterogeneous Clients In Wireless Network

With the rapid advancement of mobile networks and the rapid popularization of smart mobile terminals such as smart phones and tablet computers,multimedia mobile applications and content have been experiencing an explosive growth.The flourish growth of mobile terminal traffic has posed a serious challenge to the video streaming service: the visual quality of video,the richness of media content and the rapid response of on-demand resources are also increasing.In the wireless network environment,Video-on-Demand(VoD)system can provide users more personalized and diversified video services.Users no longer receive video content in a passive way,but at any time they can request the desired content.However,transplanting the VoD systems to the wireless context is still difficult,the challenge lies in three aspects.First,in the wireless network bandwidth is still a scarce resource.Second,the unstable wireless network channel conditions may lead to the discontinuous playing of video.Finally,VoD system client reception bandwidth is heterogeneous,requiring the system to meet the heterogeneous users of differentiated services.Therefore,in order to solve the above three problems,a scalable wireless VoD broadcasting system is designed for heterogeneous users.Furthermore,we propose an HQOBA(Heterogeneous Quality-Oriented Bandwidth Allocation)method to maximize the client perceptual quality.In this paper,a scalable wireless VoD broadcasting system for heterogeneous clients is proposed.The system transmits different enhancement layer stream in different network environments with the adaptability of FGS to bandwidth variation.Even if the wireless channel conditions change,our proposed system can guarantee the continuous playout and download.The FGS video stream is transmitted using the periodic broadcast protocol and the video stream is dynamically truncated according to the currently available system bandwidth and the performance of the heterogeneous user receiving bandwidth.By extending the periodic broadcast protocol to FGS video coding,we can cope with unstable channel condition of wireless network and the limited bandwidth resource.In addition,we propose a dynamic allocation algorithm of server bandwidth HQOBA based on the proposed broadcasting system to maximize the client perceptual visual quality.The bandwidth allocated to each FGS video stream is dynamically adjusted in each time slot of VoD system,by which we can dynamically allocate the server bandwidth resources.The heterogeneous clients with different reception bandwidth receive different number of enhancement layer streams in HQOBA.The bandwidth allocation of the broadcasting channels also meets the requirements of the heterogeneous client reception bandwidth,which makes the proposed VoD broadcasting system have good compatibility with heterogeneous clients.Finally,the factors that influence the bandwidth allocation of VoD broadcasting system are discussed in this paper,and the experimental results of HQOBA scheme also validate the effectiveness.