A cross-layer scheduling algorithm for H.264 video transmission over wireless networks

A cross-layer scheduling algorithm that streams pre-coded H.264 video over wireless networks to multiple users is presented. The algorithm can be used with the emerging wireless standards such as IEEE 802.16 and HSDPA. Our focus is maximizing the video perceptual quality after delivery with constraint of the limited wireless resources and the delay requirements from the practical point of view. At the application layer, the relative importance of each packet to the video perceptual quality is estimated by a Packet Relative Importance Index in a low complexity computation, which is evaluated directly in video compressed domain. At the physical layer, the channel state information is derived and an adaptive modulation coding design is introduced. Thus, the scheduling algorithm at the media access control layer for multiple mobile users is proposed depending on the information provided by the application and physical layer with the objective of maximizing the video quality. Simulations show that the proposed scheme performs significantly than the conventional scheduling schemes for video transmission.