Elastically Reliable Video Transport Protocol Over Lossy Satellite Links

As there is a growing demand for providing high-definition (HD) video and satellite TV services over satellite networks, interconnection and multimedia applications need new-type satellite services to ensure good quality-of-experience (QoE) for these Internet flows. The characteristics of satellite channels (notably the lossy and long-delay environment) can heavily influence transferring protocols exclusively designed for terrestrial network, and using a radically reliable method (TCP) or unreliable method (UDP) is not the best way for the transmission of multimedia applications over satellite networks, such as HD video. In order to cope with the contradiction between high quality and real-time transfer, this paper presents a retransmission-based partially reliable transfer protocol, called automatically partially reliable transfer protocol (APRT). For the purpose of tracing the network status, the hidden Markov model (HMM) is employed to depict reliable level of the transfer strategy. Through off-line training initialization and online prediction, current network status is then mapped to a reliable level, which can represent good video quality and minimum packet delay. Meanwhile, APRT can retransmit the lost packets as the network changing without losing key frames. Extensive simulation results show that for both single and coexisting flow scenarios, APRT can improve video quality of services (QoSs) against reliable and unreliable transfer strategies in terms of different metrics. For single video flow, PSNR of APRT outperforms than that of other strategies under lossy and long-delay networks up to 36.53% and achieves short packet delay. For coexisting scenario, APRT shows good performance in terms of latency and video quality.