Cross-layer Optimization Combining With IL-FEC For Video Transimission Over Mobile Network

With the increasement of performance of mobile equipments including smartphone and Pad etc.,people are becoming more dependently on obtain multimedia information on the Internet by using mobile equipments,accompanied by the popular and abundance of multimedia services.Recently,the data traffic in mobile networks is increased rapidly,and the traffic of video services accounts for about 70%of the total traffic.Although the development of mobile networks promotes the growth of mobile network services,the increasing mobile service data brings more and more powerful pressure and challenge to recent mobile networks.A more efficient video transmission mechanism becomes a hot research topic in recent network framework due to the crucial ratio of video service traffic to total traffic in mobile networks.Firstly,H.264/SVC which is the mainly video encoding standard recently divides a video sequence to a Base Layer(BL)and many Enhancement Layers(EL).When the BL data is transmitted in failure owing to channel fading or other reasons,EL data would be discarded even though transmitted rightly.This is because EL data is decoded depended on BL data,and this way causes the waste of bandwidth resource allocated for EL data.In recent LTE systems,although it introduces QCI mechanism in resource schedule,it adopts equal error protection(EEC)to process data in physical layer.Thus,this paper proposes an interlayer encoding method(IL-FEC)based on recent LTE frameworks and Turbo channel coding.It achieves unequal error protection(UEC)to video service data by introducing the relevant of data between different layers in the module of precoding on the side of encoding,combining iteration of co-decoding on the side of decoding.Secondly,in the evaluation of QoE of the transmission quality for video service from end to end,the delay of video image,video caton and other parameters has higher importance than the quality of video image in terms of QoE.Hence,from this point of view,this paper provides an advanced BFPF schedule algorithm which combines the states of decoder on the side of receiver,based on PF resource schedule algorithm in MAC layer in recent LTE systems.It aims at enhancing the QoE of video transmission and facheieves the cross-layer optimization of video data transmission.This paper combines the IL-FEC channel coding/decoding and the cross-layer optimization of BFPF schedule algorithm.The simulation shows,with the same decoding performance of EL data,when transmitting video service data in mobile networks,the BLER of BL data is reduced about 30%so that the number of HARQ retransmission is also reduced effectively.Moreover,the delay and caton of video service from end to end have fallen dramatically about 50%.The scheme of this paper reduces the consummation of bandwidth resource of mobile video service data transmission efficiently,increases the QoE from end to end and enhances the supporting ability for video service in recent mobile networks.