A Cross-Layer Design Approach to Multicast in Wireless Networks

Abstract

We study rate optimization for multicast communications at the media access control (MAC) layer, and explore transport layer erasure coding to enhance multicast reliability in wireless networks. We start with investigating network models with single-input-single-output (SISO) links. For threshold-T based multicast policies, we characterize the optimal transmission rates that maximize the throughput in stable networks and in saturated networks, respectively. We investigate the tradeoff between stability and throughput therein. We then generalize our study to network models with multiple-input-multiple-output (MIMO) links and non-i.i.d. channel links, and investigate the optimal transmission rate. In addition, to ensure multicast reliability while no retransmission is required at the MAC layer, we propose to use transport layer erasure coding for reliability enhancement, where the problem boils down to jointly optimizing the transmission rate and the multicast threshold. We provide a solution to this optimization problem accordingly