A cross-layer QoS scheme for MPEG-4 streams

Video streams over wireless channel requires stringent QoS constraints, such as low packet loss and latency. It becomes the main challenge to design a network to achieving these QoS objectives. In this paper, a priority-based cross-layer quality-of-service (QoS) scheme for wireless channel and video applications was introduced. The application layer sends an inquiry to examine the link state. Respectively, the link layer feedbacks a trigger to indicate the state of link information. On the other hand, unequal error protection was adapted for retransmission decision. When a packet was dropped, ARQ decision will be make according to the priority-based adaptive QoS of MPEG-4 video streams. Simulation results demonstrate that video processed in cross-layer scheme experiences much better than that of traditional scheme, not only in PSNR but also in visual quality.