Cooperative packet transmission scheduling between multicast and unicast flows for communication efficiency in wireles LAN

Abstract

Recently, wireless LAN has been diffused. Although unicast transmission is mainly used currently, multicast transmission, such as distribution of multimedia information, is expected to increase in near future. Thus, channel utilization of wireless LAN needs to be improved in general environments where multicast flows coexist with unicast. Although many packet transmission methods that achieve high channel utilization have been proposed, they focus on situations that only either multicast or unicast transmission exists. In this paper, focusing on general environments where multicast and unicast flows are communicated in parallel, we propose new packet transfer scheduling so that high network bandwidth and channel utilization can be realized by transmitting packets at as high rate as possible, by reducing packet loss, and by omitting the overhead to communicate control frames. These improvements are realized by effective cooperation between multicast and unicast flows. Evaluation results demonstrate that network throughputs of both unicast and multicast are increased while decreasing packet transfer delay.