Multimedia & Applications

Biography

Biography: Tsang-Ling Sheu

Abstract

Multicast is an effective mechanism to substantially save network bandwidth while transmitting real-time video streams in a wireless mobile communication network (such as 3G/4G). However, today it lacks of a packet retransmission scheme for real-time video multicasting in mobile communication networks. The last hop of a mobile communication network is defined as the hop between a base station (BS)/gateway and a mobile station (MS). Packet errors happen very easily in the last hop because wireless channels in a mobile communication network are error-prone. As a result, packet errors in the last hop may bring a critical deterioration of video quality at MS. Besides, an end-to-end retransmission scheme, such as TCP, cannot meet the strict delay constraints of a real-time video stream. Hence, in this paper, we propose a retransmission scheme to improve the quality of video multicasting in the last-hop of a mobile communication network. The proposed retransmission scheme requires MS in a multicast group to feedback ARQ (Automatic Repeated Request) messages to BS/Gateway. The proposed retransmission scheme is invoked under three considerations: the extra bandwidth cost for retransmitting the erroneous blocks, the retransmission delay, and the acceptable delay constraints at MS. NS-3 simulation is performed to demonstrate the superiority of the proposed retransmission scheme. From simulation, we reveal how well the retransmission scheme can reconstruct the quality of a multicast video stream at MS. Furthermore, the extra bandwidth cost for retransmitting erroneous blocks is investigated.