A Cooperative Multicast Strategy in Wireless Networks

Multicast is a bandwidth-efficient mechanism to provide wireless services for a group of terminals. Providing reliable wireless multicast is challenging due to packet loss and channel fading. In this research, we investigate the medium-access-control (MAC) layer cooperation to enhance the reliability of wireless multicast. We show that the optimal relaying strategy is a pure threshold policy, i.e., the optimal number of relays is bounded by a threshold. We also propose a simple and efficient algorithm to find the optimal time allocation for the direct and relay transmissions.