A new high layer ACK mechanism for real-time video transmission in multi-hop wireless network

摘要

This paper proposes a new high layer ACK mechanism for real-time video transmission in multi-hop wireless network. In order to ensure the quality-of-service (QoS) of the video and minimize the frequency of retransmitting the lost packets of B-frames and P-frames, an ACK is only sent in reply if the packet belonging to I-frame is received successfully. In the end-to-end link, if some of intermediate nodes' rates of success forwarding are below the threshold value, one of these intermediate nodes, which saves the copy of current packet, replies ACK to the source node and forwards the packet to the destination node. Finally, the intermediate node waits the ACK replied by destination node. In this ACK mechanism, nodes can send the next packet immediately. When the packet is not transmitted to the destination node, the next packet needs not to wait the retransmission of its previous packet. If the nodes do not receive the ACK from the destination node, they will periodically retransmit the copy of packets in a fixed time period. The simulation is performed in MATLAB, the result show that this mechanism can reduce the average delay of packets delivery and improve the QoS of the received video.