A practical ACK-leader selection scheme for multicast QoS enhancement

Reliable multicast is desired to meet the QoS requirements of multimedia traffic. In this paper, we propose a practical and adaptive ACK-leader selection scheme to enhance the reliability of multicast. The proposed scheme addresses the problem of selecting appropriate multicast recipients with high PER to engage in acknowledging data packets. The PER estimation is improved by exploiting the bitmap of B-ACK frame. The correlation indicated by bitmaps is also utilized to further reduce the number of selected ACK-leaders. Particular procedure of multicast policy matching the proposed ACK-leader selection is also investigated. Simulation results show that the proposed scheme can use less number of ACK-leaders to achieve higher performance of multicast compared to existing selection scheme.